I'm seeking advice.

We're currently looking to replace our system boiler and hot water tank.
The boiler and tank are too small for our house (detached, 30s, 3 beds,
one bath, 3 downstairs rooms with small kitchen extension).

We've had a couple of heating engineers in and are receiving conflicting
advice; as I am sure I will get here!

First chap said that a combi would be no good for our house. He said he
would never use them and that they are no good for a house of our size.
He also said that we would need to replace our old iron gas supply, even
though it appears to be large enough.

Second man said that a combi would be fine, he recommended a
floor-standing, Worcester Greenflow. Said we wouldn't need to replace
the gas supply it would be fine. Said a wall mounted boiler would not be
big enough. Having a floor standing boiler is less than ideal as it
would take up much needed floor space in our small kitchen.

Third man says we would be fine with a wall mounted combi but said we'd
need a new gas supply as old iron pipes a likely to rust and this can
get inside the boiler. He also said they are prone to cracking and leaking.

What we would ideally like is: a combi, wall-mounted, with no new gas
supply if possible. We are a small family (2 little kids), with not a
lot of spare cash, and not a lot of room in our kitchen for the boiler.

I know that, ultimately, the decision is ours but if anyone has any
advice for us it would be much appreciated.

thanks in advance, dan

On Wed, 21 Dec 2005 15:07:14 +0000, danw
wrote:

I'm seeking advice.

Gas pipe-the main thing is,is the diameter adequate enough to pass the
correct flow rate without excessive pressure loss? if so then it
shouldnt need replaceing if its in good condition. There may be
minimal chance of dust/rust but its unlikely that this would bother
the boiler as the flow would not be at a high rate and it would not be
turbullent flow. Anyway its easy enough to put a filter on the gas
inlet if the boiler doesnt already incorporate one.

The main issue with type of boiler is water delivery rate. Now then if
you have a family house and have high water demands I'd suggest you
stick with a system boiler and cylinder. Whether that cylinder is open
vented or pressurised is up to you!.

Combi technology has improved greatly but for big family houses,they
can still be tedious.





Remove antispam and add 670 after bra to email

http://www.no2id.org/

danw wrote:
I'm seeking advice.

We're currently looking to replace our system boiler and hot water tank.
The boiler and tank are too small for our house (detached, 30s, 3 beds,
one bath, 3 downstairs rooms with small kitchen extension).

We've had a couple of heating engineers in and are receiving conflicting
advice; as I am sure I will get here!

First chap said that a combi would be no good for our house. He said he
would never use them and that they are no good for a house of our size.
He also said that we would need to replace our old iron gas supply, even
though it appears to be large enough.

Second man said that a combi would be fine, he recommended a
floor-standing, Worcester Greenflow. Said we wouldn't need to replace
the gas supply it would be fine. Said a wall mounted boiler would not be
big enough. Having a floor standing boiler is less than ideal as it
would take up much needed floor space in our small kitchen.

Third man says we would be fine with a wall mounted combi but said we'd
need a new gas supply as old iron pipes a likely to rust and this can
get inside the boiler. He also said they are prone to cracking and leaking.

What we would ideally like is: a combi, wall-mounted, with no new gas
supply if possible. We are a small family (2 little kids), with not a
lot of spare cash, and not a lot of room in our kitchen for the boiler.

I know that, ultimately, the decision is ours but if anyone has any
advice for us it would be much appreciated.

thanks in advance, dan

Personally (and I'm not a heating engineer!), I'd say your house would
suit a combi perfectly. We have a 4 bed detatched and we run happily off
a combi with no real problems at all.
The only real advice I can give is to measure your flow of cold water,
(in litres per min) and then make sure you get a combi that can heat
roughly that much water. I guess what I mean is, if you only get 12L per
min, there is no point buying a big floor standing combi, that will heat
20L/min. Equally, if you get 20L, then you are going to have problems
with a 12L/min combi.

Obviously, this is all in my opinion only!

Cheers
Mike

On Wed, 21 Dec 2005 15:07:14 +0000, danw
wrote:

I'm seeking advice.

We're currently looking to replace our system boiler and hot water tank.
The boiler and tank are too small for our house (detached, 30s, 3 beds,
one bath, 3 downstairs rooms with small kitchen extension).

We've had a couple of heating engineers in and are receiving conflicting
advice; as I am sure I will get here!

First chap said that a combi would be no good for our house. He said he
would never use them and that they are no good for a house of our size.
He also said that we would need to replace our old iron gas supply, even
though it appears to be large enough.

Second man said that a combi would be fine, he recommended a
floor-standing, Worcester Greenflow. Said we wouldn't need to replace
the gas supply it would be fine. Said a wall mounted boiler would not be
big enough. Having a floor standing boiler is less than ideal as it
would take up much needed floor space in our small kitchen.

Third man says we would be fine with a wall mounted combi but said we'd
need a new gas supply as old iron pipes a likely to rust and this can
get inside the boiler. He also said they are prone to cracking and leaking.

What we would ideally like is: a combi, wall-mounted, with no new gas
supply if possible. We are a small family (2 little kids), with not a
lot of spare cash, and not a lot of room in our kitchen for the boiler.

I know that, ultimately, the decision is ours but if anyone has any
advice for us it would be much appreciated.

thanks in advance, dan

There are a whole bunch of things he

- If you are thinking about any form of direct mains fed hot water,
then measuring the cold water rate at the cold tap in the kitchen is
very important. If the supply is less than about 20 litres/min, you
will be quite disappointed by the results in comparison with the
existing storage system in terms of time to fill the bath. With two
small kids, this will matter increasingly.

- An instantaneous boiler, be it a simple combi or one with storage
like the floor standing WB Highflow (was that what you meant?) need a
substantial gas supply. Normally in a run of copper tube, 22mm is
used and on longer runs, 28mm. Remember that the iron pipe will have
thicker walls and the inner diameter of something that looks to be
around 22mm or more on the outside is not a lot larger than 15mm on
the inside. The fitter should do the proper calculations, but it is
possible that the pipe is inadequate. If you don't want to change
the supply, this may rule out combi type boilers.

- The house size is not typically that important. With either a combi
or a system boiler, in modern models the burner modulates, meaning
reduces output to match required load. In a house of your size, it
would be unlikely that the heating load would exceed the requirement
of water heating unless you went for a peewilly little combi of
11-13lpm which you probably wouldn't want anyway.

- Bear in mind that combis have a flow rate specified in litres/min
for a 35 degree temperature rise normally. If you consider that in
the winter, cold mains temperature is often around 5 degrees, the
effective bath water temperature being 40 degrees means that the
specified flow rate becomes the total flow rate.
For a 150 litre bath, the filling time can be frustrating if the
boiler is too small.

- CPSU boilers like the WB Highflow help with this to a point, but
only to the extent of the store. Once that runs out, the rate is
reduced to that of the unaided boiler - around 12lpm. The
manufacturer quotes 20lpm, but that includes the store behaviour and
they don't specify how they made the measurement. Either way, it's
possible to calculate how long it will take to deliver a certain
volume of water at a certain temperature.
Nevertheless, with the caveats, this might be a good choice. Have you
thought about siting it in the airing cupboard instead of the
cylinder? Is recovering the cylinder space important?

- There are larger wall mounted combi boilers with storage like the
Alpha. However, at dimensions of 900x600x450, it is not going to look
petite on your kitchen wall. Of course it needs a substantial gas
supply.

- If you wanted the minimum impact solution, a replacement system
boiler (condensing model) and a fast recovery perhaps slightly larger
cylinder could well be a good option. You could choose a boiler that
wouldn't require a supply upgrade and the HW performance could be
improved substantially.



--

..andy

In article ,
Mike Hibbert wrote:
Personally (and I'm not a heating engineer!), I'd say your house would
suit a combi perfectly. We have a 4 bed detatched and we run happily off
a combi with no real problems at all.

The size of the house has little bearing on a combi or not - pretty well
all are large enough to heat them. It's the speed of hot water delivery
that may be a problem for baths, etc.

--
*I didn't fight my way to the top of the food chain to be a vegetarian.

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 21 Dec 2005 15:07:14 +0000, danw wrote:

I'm seeking advice.

We're currently looking to replace our system boiler and hot water tank.
The boiler and tank are too small for our house (detached, 30s, 3 beds,
one bath, 3 downstairs rooms with small kitchen extension).

We've had a couple of heating engineers in and are receiving conflicting
advice; as I am sure I will get here!

First chap said that a combi would be no good for our house. He said he
would never use them and that they are no good for a house of our size.
He also said that we would need to replace our old iron gas supply, even
though it appears to be large enough.

Second man said that a combi would be fine, he recommended a
floor-standing, Worcester Greenflow. Said we wouldn't need to replace
the gas supply it would be fine. Said a wall mounted boiler would not be
big enough. Having a floor standing boiler is less than ideal as it
would take up much needed floor space in our small kitchen.

Third man says we would be fine with a wall mounted combi but said we'd
need a new gas supply as old iron pipes a likely to rust and this can
get inside the boiler. He also said they are prone to cracking and leaking.

What we would ideally like is: a combi, wall-mounted, with no new gas
supply if possible. We are a small family (2 little kids), with not a
lot of spare cash, and not a lot of room in our kitchen for the boiler.

I know that, ultimately, the decision is ours but if anyone has any
advice for us it would be much appreciated.

For a wall hung combi you have to ask yourself if you are going to be
happy with around 10 litres/minute of HW flow. You may well be or you may
well not be, the matter is one of taste and _must_ be answered before the
rest of the questions.

I would expect that for your house around 15-20kW will be
sufficient, what is the power of the current boiler? Did it ever heat the
house?

A 'standard' (900-450mm) replacement unvented cylinder complying to
current regs should provided enough HW for a bath every 20mins.

IME it is often not the capacity of the cylinder that is the problem but
the reheat time.

If the gas pipe work is not rusting and adequate size it can be reused.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"danw" wrote in message
...
I'm seeking advice.

We're currently looking to replace our system boiler and hot water tank.
The boiler and tank are too small for our house (detached, 30s, 3 beds,
one bath, 3 downstairs rooms with small kitchen extension).

We've had a couple of heating engineers in and are receiving conflicting
advice; as I am sure I will get here!

First chap said that a combi would be no good for our house. He said he
would never use them and that they are no good for a house of our size.
He also said that we would need to replace our old iron gas supply, even
though it appears to be large enough.

Second man said that a combi would be fine, he recommended a
floor-standing, Worcester Greenflow. Said we wouldn't need to replace
the gas supply it would be fine. Said a wall mounted boiler would not be
big enough. Having a floor standing boiler is less than ideal as it
would take up much needed floor space in our small kitchen.

Third man says we would be fine with a wall mounted combi but said we'd
need a new gas supply as old iron pipes a likely to rust and this can
get inside the boiler. He also said they are prone to cracking and
leaking.

What we would ideally like is: a combi, wall-mounted, with no new gas
supply if possible. We are a small family (2 little kids), with not a
lot of spare cash, and not a lot of room in our kitchen for the boiler.

I know that, ultimately, the decision is ours but if anyone has any
advice for us it would be much appreciated.

thanks in advance, dan

FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50 fitted,
bath filling is on a par with the old cylinder system, its wall mounting and
stuck in the loft on the gable wall - worth a look

Regards Jeff

In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50 fitted,
bath filling is on a par with the old cylinder system, its wall mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

--
*I'm not as think as you drunk I am.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50 fitted,
bath filling is on a par with the old cylinder system, its wall mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)

Regards Jeff

On Thu, 22 Dec 2005 11:51:26 -0000, "Jeff"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50 fitted,
bath filling is on a par with the old cylinder system, its wall mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)


Well, yes, one would hope.

The point is that one's perspective depends on the place from which
one starts.

--

..andy

Dave Plowman (News) wrote:
In article ,
Mike Hibbert wrote:

Personally (and I'm not a heating engineer!), I'd say your house would
suit a combi perfectly. We have a 4 bed detatched and we run happily off
a combi with no real problems at all.


The size of the house has little bearing on a combi or not - pretty well
all are large enough to heat them. It's the speed of hot water delivery
that may be a problem for baths, etc.

Thanks for all the replies.

Speed of hot water delivery is not a major problem for me. At present,
the system boiler + tanks provides a very slow delivery of hot water and
it's not really enough to fill our bath.

My assumption is that a combi would take it closer to the cold water
pressure, though I may be wrong here.

It's likely that, once we have a shower fitted, baths will be a rare
occurrence. So, waiting for one to fill wil not be a major problem.

Dan.

Thanks for all the info.

Andy Hall wrote:
- If you are thinking about any form of direct mains fed hot water,
then measuring the cold water rate at the cold tap in the kitchen is
very important. If the supply is less than about 20 litres/min, you
will be quite disappointed by the results in comparison with the
existing storage system in terms of time to fill the bath. With two
small kids, this will matter increasingly.

Dumb question, but is measuring the water rate as simple as timing the
time it takes to fill a known volume, then extraploting?

Nevertheless, with the caveats, this might be a good choice. Have you
thought about siting it in the airing cupboard instead of the
cylinder? Is recovering the cylinder space important?

Yes, at present, the boiler and the hot water tank are in our smallest
bedroom. We don't really want to place them in another bedroom and we
don't have anywhere else we can put it. Unless we go for the loft but we
have no brick wall in our loft, so that would increase expense we believe.

thanks, dan

Ed Sirett wrote:
I would expect that for your house around 15-20kW will be
sufficient, what is the power of the current boiler?

Pass

Did it ever heat the
house?

I think it would just about mange it if we had thermostatic readioator
valves. As it is, some rooms end up too hot, others too cold.

thank, dan

On Thu, 22 Dec 2005 19:10:43 +0000, danw
wrote:

Thanks for all the info.

Andy Hall wrote:
- If you are thinking about any form of direct mains fed hot water,
then measuring the cold water rate at the cold tap in the kitchen is
very important. If the supply is less than about 20 litres/min, you
will be quite disappointed by the results in comparison with the
existing storage system in terms of time to fill the bath. With two
small kids, this will matter increasingly.

Dumb question, but is measuring the water rate as simple as timing the
time it takes to fill a known volume, then extraploting?

Basically yes. Simply time how long it takes to fill a reasonable
volume (e.g. marked bucket) and calculate from there.

One thing to realise is that it is not so much the pressure that
matters but rather the flow rate, because that ultimately affects
basic cold delivery rate.

For example, in an older property, and even some newer ones, the
service pipe from the street may not be particularly large. This is
because the assumption was that you would be filling a tank. Within
the house, it's conventional to have 15mm for cold water mains from
the rising point to the roof tank. Obviously you can do something
about the latter because you would run a 22mm pipe to the combi and
the same to the bath from there. However, depending on distance, a
new service pipe can run to several £k.

None of this is necessarily a problem, but it's a basic check that
people miss, assuming that because the supply now comes directly from
the main it must be faster and better. Yes, the pressure may be
higher on the back of your hand for low flow rates, but the flow rate
may be poor. The water suppliers are only legally required to
deliver 9 lpm which is pathetic.

Consider also that if you are likely to migrate to a shower, whether
you like the feeling of pressure or also good flow rate. It's
reasonably easy with a small shower head to produce a sensation of
pressure rather like needles on the skin (even using an electric
shower). However, you might or might not like that. Personally, I
like both flow and a degree of pressure rather than a dribble, but I
don't want to feel I'm pressure washing.





Nevertheless, with the caveats, this might be a good choice. Have you
thought about siting it in the airing cupboard instead of the
cylinder? Is recovering the cylinder space important?

Yes, at present, the boiler and the hot water tank are in our smallest
bedroom. We don't really want to place them in another bedroom and we
don't have anywhere else we can put it. Unless we go for the loft but we
have no brick wall in our loft, so that would increase expense we believe.




Another option is a heat bank. In your situation, a loft
installation of one could be a possibility and it can be heated with a
system boiler. With this, you can have mains pressure HW but
without a large box in the kitchen.
Have a look at www.heatweb.com




--

..andy

"Andy Hall" wrote in message
...
On Thu, 22 Dec 2005 11:51:26 -0000, "Jeff"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50
fitted,
bath filling is on a par with the old cylinder system, its wall
mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed
one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one
box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)


Well, yes, one would hope.

The point is that one's perspective depends on the place from which
one starts.

--

.andy


Alpha - just wait 'till it goes wrong. God awful boilers, same league as
Biasi and Ariston. I'd rather have a Plumb Center EVO.
Go Worcester or Vaillant - Rolls Royce boilers with customer service and
technical support to match. Glowworm or Baxi also at a push.

If you have two or more bathrooms/shower rooms, I strongly recommend
installing an electric shower in one of them (the most infrequesntly used)
if you plump for a combi. One day the diverter valve or flow switch will
malfunction in your boiler and you'll have bugger all hot water until it
gets repaired.

Angus

On Thu, 22 Dec 2005 23:07:14 +0000, Fentoozler wrote:

"Andy Hall" wrote in message
...
On Thu, 22 Dec 2005 11:51:26 -0000, "Jeff"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50
fitted,
bath filling is on a par with the old cylinder system, its wall
mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed
one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one
box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)


Well, yes, one would hope.

The point is that one's perspective depends on the place from which
one starts.

--

.andy


Alpha - just wait 'till it goes wrong. God awful boilers, same league as
Biasi and Ariston. I'd rather have a Plumb Center EVO.
Go Worcester or Vaillant - Rolls Royce boilers with customer service and
technical support to match. Glowworm or Baxi also at a push.

Baxi must have improved somewhat since the Barcelona?



If you have two or more bathrooms/shower rooms, I strongly recommend
installing an electric shower in one of them (the most infrequesntly used)
if you plump for a combi. One day the diverter valve or flow switch will
malfunction in your boiler and you'll have bugger all hot water until it
gets repaired.

Agreed.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Ed Sirett" wrote in message
news
On Thu, 22 Dec 2005 23:07:14 +0000, Fentoozler wrote:

"Andy Hall" wrote in message
...
On Thu, 22 Dec 2005 11:51:26 -0000, "Jeff"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50
fitted,
bath filling is on a par with the old cylinder system, its wall
mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed
one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one
box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)


Well, yes, one would hope.

The point is that one's perspective depends on the place from which
one starts.

--

.andy


Alpha - just wait 'till it goes wrong. God awful boilers, same league as
Biasi and Ariston. I'd rather have a Plumb Center EVO.
Go Worcester or Vaillant - Rolls Royce boilers with customer service and
technical support to match. Glowworm or Baxi also at a push.

Baxi must have improved somewhat since the Barcelona?



If you have two or more bathrooms/shower rooms, I strongly recommend
installing an electric shower in one of them (the most infrequesntly
used)
if you plump for a combi. One day the diverter valve or flow switch will
malfunction in your boiler and you'll have bugger all hot water until it
gets repaired.

Agreed.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html


They have - many recent boilers designed with the Service Engineer in mind.

On Thu, 22 Dec 2005 19:13:01 +0000, danw wrote:

Ed Sirett wrote:
I would expect that for your house around 15-20kW will be
sufficient, what is the power of the current boiler?

Pass

Did it ever heat the
house?

I think it would just about mange it if we had thermostatic radiator
valves. As it is, some rooms end up too hot, others too cold.

The boiler will have a maker, model and possible model number. Often the
model number is a strong hint as to the power without looking for the
rating plate.[1] If you find the rating plate it will have a lot of info
the one I'd like to know is something like "input rating", "output
rating", "Qin" or "Qout".

[1] Eg. Potterton Profile 50 means. 50k BTU/hr or about 15kW.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Thu, 22 Dec 2005 19:05:30 +0000, danw wrote:

Dave Plowman (News) wrote:
In article ,
Mike Hibbert wrote:

Personally (and I'm not a heating engineer!), I'd say your house would
suit a combi perfectly. We have a 4 bed detatched and we run happily off
a combi with no real problems at all.


The size of the house has little bearing on a combi or not - pretty well
all are large enough to heat them. It's the speed of hot water delivery
that may be a problem for baths, etc.

Thanks for all the replies.

Speed of hot water delivery is not a major problem for me. At present,
the system boiler + tanks provides a very slow delivery of hot water and
it's not really enough to fill our bath.

My assumption is that a combi would take it closer to the cold water
pressure, though I may be wrong here.

It's likely that, once we have a shower fitted, baths will be a rare
occurrence. So, waiting for one to fill wil not be a major problem.

OK. So you'd like to be able to have a good shower. The presenting problem
is that the bath filling rate is poor. (This could be due to a lot of
reasons but a very plausible reason for this age of property is that some
of the bathroom water is being delivered from the roof tank via the HW
cylinder through very badly restricted iron pipes.)

You might find that replacing some of the pipes and possibly adding a pump
serves you better in the medium term than a new boiler. With sensible use
of plastic pipes this job may not be as expensive or as disruptive as you
might imagine.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

Andy Hall wrote:

The water suppliers are only legally required to
deliver 9 lpm which is pathetic.


Bear in mind also that this flow rate varies according to the time of day.

Regards
Capitol

On Fri, 23 Dec 2005 20:38:10 +0000, Fentoozler wrote:

"Ed Sirett" wrote in message
news
On Thu, 22 Dec 2005 23:07:14 +0000, Fentoozler wrote:

"Andy Hall" wrote in message
...
On Thu, 22 Dec 2005 11:51:26 -0000, "Jeff"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50
fitted,
bath filling is on a par with the old cylinder system, its wall
mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed
one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one
box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)


Well, yes, one would hope.

The point is that one's perspective depends on the place from which
one starts.

--

.andy


Alpha - just wait 'till it goes wrong. God awful boilers, same league as
Biasi and Ariston. I'd rather have a Plumb Center EVO.
Go Worcester or Vaillant - Rolls Royce boilers with customer service and
technical support to match. Glowworm or Baxi also at a push.

Baxi must have improved somewhat since the Barcelona?



If you have two or more bathrooms/shower rooms, I strongly recommend
installing an electric shower in one of them (the most infrequesntly
used)
if you plump for a combi. One day the diverter valve or flow switch will
malfunction in your boiler and you'll have bugger all hot water until it
gets repaired.

Agreed.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html


They have - many recent boilers designed with the Service Engineer in mind.

Um... You could argue that the Barcelona was designed with the Service
Engineer in mind...


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

In message .uk, Ed
Sirett writes

They have - many recent boilers designed with the Service Engineer in mind.

Um... You could argue that the Barcelona was designed with the Service
Engineer in mind...

As in

.... ensure they're never out of work designed ?

--
geoff

Hi Ed,

I was wondering if you had seen any / many Wickes Combis, the 102,000 btu
item ?
It is a Halstead, possibly the Ace High, with a Wickes badge ?

Thanks,

Nick

On Mon, 26 Dec 2005 16:32:29 +0000, raden wrote:

In message .uk, Ed
Sirett writes

They have - many recent boilers designed with the Service Engineer in mind.

Um... You could argue that the Barcelona was designed with the Service
Engineer in mind...

As in

... ensure they're never out of work designed ?

That's about it.




--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many Wickes Combis, the 102,000 btu
item ?
It is a Halstead, possibly the Ace High, with a Wickes badge ?

The sheds and catalogues (Screwfux and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ. The gist of it would
be 1) "You get what you pay for (which might also be a name)."
2) "The cost of correct and legal fitting is so high relative to the
unit that it does not pay to go to the cheap end.

For a few hundred more there are some good 35kW combis.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Ed Sirett" wrote in message
news
On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many Wickes Combis, the 102,000 btu
item ?
It is a Halstead, possibly the Ace High, with a Wickes badge ?

The sheds and catalogues (Screwfux and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ. The gist of it would
be 1) "You get what you pay for (which might also be a name)."
2) "The cost of correct and legal fitting is so high relative to the
unit that it does not pay to go to the cheap end.

For a few hundred more there are some good 35kW combis.

Halstead boilers are decent. They are no Ravenheats.

"Ed Sirett" wrote in message
news
On Wed, 21 Dec 2005 15:07:14 +0000, danw wrote:

For a wall hung combi you have to ask
yourself if you are going to be
happy with around 10 litres/minute of
HW flow.

Oh NO. Not this garbage again. And you claim to be a professional as well.
Wall hung combis can go up to 22 litres/min. To state that they are only
fit for 10 litres/min is gross misinformation.

"Dave Plowman (News)" through a haze of senile
flatulence wrote in message ...
In article ,
Jeff wrote:

FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50 fitted,
bath filling is on a par with the old cylinder system, its wall mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Only if the cylinder is on the wall the other side of the bath taps, the
bath taps are wide bore, high flow, low pressure taps, The cold water tank
is directly above the cylinder and the cold feed is 28mm. Most are not like
that and just one 22mm elbow can reduce the flow quite a bit. Have the
cylinder and tanks away from each other and the bathroom down the hall and
the flow is greatly reduced to that about the same as the Alpha CD50.

"Dave Plowman (News)" through a haze of senile
flatulence wrote in message ...
In article ,
Jeff wrote:

FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50 fitted,
bath filling is on a par with the old cylinder system, its wall mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Only if the cylinder is on the wall the other side of the bath taps, the
bath taps are wide bore, high flow, low pressure "individual" taps, The cold
water tank is directly above the cylinder and the cold feed is 28mm. Most
are not like that and just one 22mm elbow can reduce the flow quite a bit.
Have the cylinder and tanks away from each other, the bathroom down the hall
and a mixer tap and the flow is greatly reduced to that about the same as
the Alpha CD50.

"Fentoozler" nospam@mapson wrote in message
...
"Andy Hall" wrote in message
...
On Thu, 22 Dec 2005 11:51:26 -0000, "Jeff"
wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Jeff wrote:
FWIW - 4 bed house, 2 bathrooms + ensuite, just had a Alpha CD50
fitted,
bath filling is on a par with the old cylinder system, its wall
mounting
and stuck in the loft on the gable wall - worth a look

You must have had a very poor 'cylinder system'. A correctly designed
one
should have given twice the flow at double the temperature of an Alpha
CD50 thus filling a bath to the wanted temperature in a quarter of the
time.

Yes it was poor - old thorn boiler and cylinder in the old outside
loo/coalhouse.
I agree that any combi is not going to me a match for a modern storage
system but for a household that mainly showers the alpha is a superb one
box
solution (the mira shower is superb vs the old 9.5Kw 'leccy one)


Well, yes, one would hope.

The point is that one's perspective depends on the place from which
one starts.

--

.andy

Alpha - just wait 'till it goes wrong. God awful boilers, same league as
Biasi and Ariston.

Total ********. You have never seen one. Alpha and Ariston have revamps
their whole ranges and give long guarantees. The older models were not that
brilliant, yet I know some who always swore by Alpha. The Alpha CD50 has a
FIVE year guarantee with a stainless steel water vessel and the Ariston
Microgenus has a 2 year guarantee with 5 years on the plate heat exchanger.
I have had a Microgenus for 3 years and it has been perfect. At the time it
was the smallest cased combi around. It is also has a very simple layout.
The main heat exchanger slides in and out. A doddle to work on.

Even BIASI are reliable and simple boilers (in the non-condensing version),
using industry standard parts.

I'd rather have a Plumb Center EVO.
Go Worcester or Vaillant - Rolls Royce boilers with customer service and
technical support to match.

You really don't know do you. The RR boilers are Viessmann, ECO-Hometec,
ATAG, etc.

Glowworm or

Glow Worm are made by Vaillant with the Vaillant parts.

Baxi also at a push.

A relative of mine had a Baxi 105e fitted 3 years ago (with the water vessel
inside). I stayed in their house and was quite impressed with it. They had
a small bath yet it filled it with no problems at all. No trickle fills. I
aced her if she thought the bath fills were slow, she said she never noticed
and it fills fast enough. The 105e is one of the better boilers Baxi have
made. The condensing version has the secondary heat exchanger and all
boiler with these should be avoided.

If you have two or more bathrooms/shower rooms, I strongly recommend
installing an electric shower in one of them

Oh my God!!! What tripe. Electric showers are made by Satan himself.
Electric backup can be provided by an in-line instant heater in the DHW
draw-off.

"Ed Sirett" wrote in message
news
Glowworm or Baxi also at a push.

Baxi must have improved somewhat since the Barcelona?

It is now badged as the Potterton Promax. The better boilers have a Baxi
badge.

If you have two or more bathrooms/shower
rooms, I strongly recommend
installing an electric shower in one of them
(the most infrequesntly used)
if you plump for a combi. One day the
diverter valve or flow switch will
malfunction in your boiler and you'll have
bugger all hot water until it gets repaired.

Agreed.

Another one who has never heard of an in-line instant electric heater in the
combi DHW draw-off.

"Nick" wrote in message
...
Hi Ed,

I was wondering if you had seen any / many Wickes Combis, the 102,000 btu
item ?

A decent boiler with a decent flowrate and a doddle to fit. The
non-condensing version was fine with a two year guarantee. You CAN'T fit
this boiler as it is not a condenser, unless the flue plume is nuisance.

It is a Halstead, possibly the Ace High, with a Wickes badge ?

Yes.

"Ed Sirett" wrote in message
news
On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many
Wickes Combis, the 102,000 btu item ?
It is a Halstead, possibly the Ace High,
with a Wickes badge ?

The sheds and catalogues (Screwfux
and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ.

Please don't has you clearly don't know too much about them. 10 litre/min
from wall hung combis? Please. The FAQ needs to have correct and factual
information, nothing that is misleading, no old wives tales or personal
prejudices.

On Tue, 27 Dec 2005 10:16:36 -0000, "Doctor Drivel"
wrote:


"Ed Sirett" wrote in message
news
On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many
Wickes Combis, the 102,000 btu item ?
It is a Halstead, possibly the Ace High,
with a Wickes badge ?

The sheds and catalogues (Screwfux
and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ.

Please don't has you clearly don't know too much about them. 10 litre/min
from wall hung combis? Please. The FAQ needs to have correct and factual
information, nothing that is misleading, no old wives tales or personal
prejudices.


So you won't be contributing then?


--

..andy

"Andy Hall" wrote in message
...
On Tue, 27 Dec 2005 10:16:36 -0000, "Doctor Drivel"
wrote:


"Ed Sirett" wrote in message
news
On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many
Wickes Combis, the 102,000 btu item ?
It is a Halstead, possibly the Ace High,
with a Wickes badge ?

The sheds and catalogues (Screwfux
and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ.

Please don't has you clearly don't know too much about them. 10 litre/min
from wall hung combis? Please. The FAQ needs to have correct and factual
information, nothing that is misleading, no old wives tales or personal
prejudices.


So you won't be contributing then?

I will edit the content.

On Tue, 27 Dec 2005 10:23:39 +0000, Andy Hall wrote:

On Tue, 27 Dec 2005 10:16:36 -0000, "Doctor Drivel"
wrote:


"Ed Sirett" wrote in message
news
On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many
Wickes Combis, the 102,000 btu item ?
It is a Halstead, possibly the Ace High,
with a Wickes badge ?

The sheds and catalogues (Screwfux
and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ.

Please don't has you clearly don't know too much about them. 10 litre/min
from wall hung combis? Please. The FAQ needs to have correct and factual
information, nothing that is misleading, no old wives tales or personal
prejudices.


So you won't be contributing then?

I'm about half way through. I'll willingly take into consideration
everyones comments. I'm quite pleased with the generosity of the good
doctor's offer to edit it. ISTR that when he looked at the Sealed CH FAQ
he only got to the first paragraph before giving up and declaring the
work as 'incomplete' and 'wrong'. This FAQ is about choosing a particular
maker/model not the type of boiler or heating system.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Ed Sirett" wrote in message
news
On Tue, 27 Dec 2005 10:23:39 +0000, Andy Hall wrote:

On Tue, 27 Dec 2005 10:16:36 -0000, "Doctor Drivel"
wrote:


"Ed Sirett" wrote in message
news On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many
Wickes Combis, the 102,000 btu item ?
It is a Halstead, possibly the Ace High,
with a Wickes badge ?

The sheds and catalogues (Screwfux
and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ.

Please don't has you clearly don't know too much about them. 10
litre/min
from wall hung combis? Please. The FAQ needs to have correct and
factual
information, nothing that is misleading, no old wives tales or personal
prejudices.

So you won't be contributing then?

I'm about half way through. I'll willingly take into consideration
everyones comments.

Take into account FACTS, NOT opinions!!!!!!!!!!!!!!!

I'm quite pleased with the generosity of the good
doctor's offer to edit it. ISTR that when he
looked at the Sealed CH FAQ
he only got to the first paragraph before
giving up and declaring the
work as 'incomplete' and 'wrong'.

If that is what I said then that is correct.

"Andy Hall" wrote in message
news
On Wed, 21 Dec 2005 15:07:14 +0000, danw
wrote:

I'm seeking advice.

We're currently looking to replace our system boiler and hot water tank.
The boiler and tank are too small for our house (detached, 30s, 3 beds,
one bath, 3 downstairs rooms with small kitchen extension).

We've had a couple of heating engineers in and are receiving conflicting
advice; as I am sure I will get here!

First chap said that a combi would be no good for our house. He said he
would never use them and that they are no good for a house of our size.
He also said that we would need to replace our old iron gas supply, even
though it appears to be large enough.

Second man said that a combi would be fine, he recommended a
floor-standing, Worcester Greenflow. Said we wouldn't need to replace
the gas supply it would be fine. Said a wall mounted boiler would not be
big enough. Having a floor standing boiler is less than ideal as it
would take up much needed floor space in our small kitchen.

Third man says we would be fine with a wall mounted combi but said we'd
need a new gas supply as old iron pipes a likely to rust and this can
get inside the boiler. He also said they are prone to cracking and
leaking.

What we would ideally like is: a combi, wall-mounted, with no new gas
supply if possible. We are a small family (2 little kids), with not a
lot of spare cash, and not a lot of room in our kitchen for the boiler.

I know that, ultimately, the decision is ours but if anyone has any
advice for us it would be much appreciated.

thanks in advance, dan

There are a whole bunch of things he

- If you are thinking about any form of direct mains fed hot water,
then measuring the cold water rate at the cold tap in the kitchen is
very important. If the supply is less than about 20 litres/min, you
will be quite disappointed by the results in comparison with the
existing storage system in terms of time to fill the bath. With two
small kids, this will matter increasingly.

- An instantaneous boiler, be it a simple combi or one with storage
like the floor standing WB Highflow (was that what you meant?) need a
substantial gas supply. Normally in a run of copper tube, 22mm is
used and on longer runs, 28mm. Remember that the iron pipe will have
thicker walls and the inner diameter of something that looks to be
around 22mm or more on the outside is not a lot larger than 15mm on
the inside. The fitter should do the proper calculations, but it is
possible that the pipe is inadequate. If you don't want to change
the supply, this may rule out combi type boilers.

- The house size is not typically that important. With either a combi
or a system boiler, in modern models the burner modulates, meaning
reduces output to match required load. In a house of your size, it
would be unlikely that the heating load would exceed the requirement
of water heating unless you went for a peewilly little combi of
11-13lpm which you probably wouldn't want anyway.

- Bear in mind that combis have a flow rate specified in litres/min
for a 35 degree temperature rise normally. If you consider that in
the winter, cold mains temperature is often around 5 degrees, the
effective bath water temperature being 40 degrees means that the
specified flow rate becomes the total flow rate.
For a 150 litre bath, the filling time can be frustrating if the
boiler is too small.

- CPSU boilers like the WB Highflow

The Highflow is NOT a CPSU.

In message .uk, Ed
Sirett writes
On Tue, 27 Dec 2005 10:23:39 +0000, Andy Hall wrote:

On Tue, 27 Dec 2005 10:16:36 -0000, "Doctor Drivel"
wrote:


"Ed Sirett" wrote in message
news On Mon, 26 Dec 2005 18:52:23 +0000, Nick wrote:

Hi Ed,

I was wondering if you had seen any / many
Wickes Combis, the 102,000 btu item ?
It is a Halstead, possibly the Ace High,
with a Wickes badge ?

The sheds and catalogues (Screwfux
and TollStation etc.) tend to rebadge
low end boilers to be sold on price.

I really must write the how to choose a boiler FAQ.

Please don't has you clearly don't know too much about them. 10 litre/min
from wall hung combis? Please. The FAQ needs to have correct and factual
information, nothing that is misleading, no old wives tales or personal
prejudices.


So you won't be contributing then?

I'm about half way through. I'll willingly take into consideration
everyones comments. I'm quite pleased with the generosity of the good
doctor's offer to edit it. ISTR that when he looked at the Sealed CH FAQ
he only got to the first paragraph before giving up and declaring the
work as 'incomplete' and 'wrong'.

What did you expect ?


--
geoff

On Tue, 27 Dec 2005 23:09:08 -0000, "Doctor Drivel"
wrote:



The Highflow is NOT a CPSU.

Just seeing if you were awake.....

The Highflow is classed as a storage combi since its store is under 70
litres and does not feed the radiators.


--

..andy