Most powerful combi boiler
 

What's the most powerful combi you can get? I haven't seen much above
35kw.

M.

"Markus Splenius" wrote in message
...
What's the most powerful combi you can get? I haven't seen much above
35kw.

M.

Worcester HI Flow?

"Markus Splenius" wrote in message
...

What's the most powerful combi you can get? I haven't seen much above
35kw.

What do you mean in power? The flowrate?

Here is a run down on combi's:

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure. To confuse a little, some can run at very low
pressures and even off tanks. Generally most are fed from the mains. It is
generally a matter of mounting the boiler and connect up the pipes. The
expert designers have done the hard work for you and put all in one case.

Types of combi:

1) The Infinitely Continuous Combi -

Heats cold mains water instantly as it runs through the combi. It never runs
out of hot water. This is the most common type of combi, generally having
lower flowrates than Nos 2 & 3 below. The largest flow rate instant combi is
a two bathroom model, 22 litres/min ECO-Hometec. Being a condenser it is
very economical too. http://www.eco-hometec.co.uk

2) Unvented Cylinder Combi -

An unvented cylinder is a similar to a conventional cylinder but run off the
high-pressure cold mains. A combi with an integral unvented cylinder has
approx 60 litre cylinder heated to approx 80C, with a quick recovery coil
that takes all the boilers output. A fast acting cylinder thermostat ensures
the boiler pumps heat into the cylinder ASAP with a recovery rate from cold
around 5-8 mins (Ariston claim 8 mins). The 80C water is blended down to
about 45-50C. e.g's, Ariston Genus 27 Plus, Glow Worm, Powermax, Alpha
CB50.

3) Infinately Continuous/Unvented cylinder combi -

An example being the Alpha CB50, a combination of both having a two stage
flowrate, of high flowrate when using the stored water with an automatic
flow regulator switching in to reduce flow to an invinately continuous
flowrate of approx 11 litres/min.
http://www.alpha-boilers.com/products/CB50.html

4) Heat Bank Combi -

Incoming water is instantly heated running through a plate heat exchanger
(as is most instantaneous combi's) that takes its heat from a "domestic hot
water only" store of water at approx 80C (instantaneous combi's take the
heat from a heat-exchanger heater via the burner). A fast acting thermostat
ensures the boiler pumps all of its heat into the store ASAP with a recovery
rate about 5-8 mins from cold. The 80C water is blended down to about
45-50C. They are generally two stage flow rates, in that when the thermal
store is exhausted it reverts to what the burner can produce, which is
approx 11-12 litre/minute. e.g. Vokera & Worcester floor standing models
(standard washing machine sizes).

N.B. The heat bank is a variation of a thermal store, but is "not" a thermal
store in the conventional sense in that a coil carrying cold mains water
runs though a store of hot water kept at about 80C. Heat-banks are far more
efficient and give higher flowrates than conventional coiled thermal stores.
The stainless steel plate heat-exchangers do not scale up so easily.

5) Combined Primary Storage Unit

(Not classed as a combi, but a derivative of a combi, but still a one box
solution, so still in the same family)

These are a combination of a large thermal store, or heat bank, and boiler
in one casing. The units are large (larger than standard washing machine
size) and floor mounted. The heating is taken off the thermal store, which
in many cases the DHW taken off the store using a plate heat-exchanger
(heat-bank). Unlike the Heat-bank in 3) above the thermal store supplies
heating "and" DHW, giving the "combined" to the title. They are available
from 1 to 2.5 bathroom models. Gledhill do an excellent condensing
version, the Gulfsream 2000. http://www.gledhill.net

Nos. 2), 3), 4) & 5) have high flowrates. No. 1 "generally" has low
flowrates but there are always exceptions and some can be high - e.g. the
ECO-Hometec infinitely continuous combi, actually has a very high flowrate.
Nos 2), 3), 4) & 5) use stored water, but in different ways. Unlike No. 1
"some" versions will eventually run cold, but that takes quite a time, hence
some are referred to as "two bathroom" models, having the ability to fill
two baths with very fast recovery rates. As hot water is being drawn off
the high rating burner is also reheating. Very rare do these combi's run
out of hot water in average use. When taking one shower the burner may be
re-heating faster than what can be drawn-off. No. 3) above uses stored
water but will not run out of hot water (high and low flowrates). Most
versions of No. 4) above are two stage flowrate models (high and low
flowrates) and will also not run out of hot water.

There are combi models that give hot water and heating simultaneously as
Combined Primary Storage Units do. Most don't as they are hot water
priority.

Many thanks for the info IMM, I shall study it tomorrow - can't take
it all in now since I just got back from the pub! :-)

Basically what I want is a shower that nails you to the floor and a
bath that fills up in 3 minutes.

M


On Thu, 6 Jan 2005 22:20:07 -0000, "IMM" wrote:


"Markus Splenius" wrote in message
.. .

What's the most powerful combi you can get? I haven't seen much above
35kw.

What do you mean in power? The flowrate?

Here is a run down on combi's:

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure. To confuse a little, some can run at very low
pressures and even off tanks. Generally most are fed from the mains. It is
generally a matter of mounting the boiler and connect up the pipes. The
expert designers have done the hard work for you and put all in one case.

Types of combi:

1) The Infinitely Continuous Combi -

Heats cold mains water instantly as it runs through the combi. It never runs
out of hot water. This is the most common type of combi, generally having
lower flowrates than Nos 2 & 3 below. The largest flow rate instant combi is
a two bathroom model, 22 litres/min ECO-Hometec. Being a condenser it is
very economical too. http://www.eco-hometec.co.uk

2) Unvented Cylinder Combi -

An unvented cylinder is a similar to a conventional cylinder but run off the
high-pressure cold mains. A combi with an integral unvented cylinder has
approx 60 litre cylinder heated to approx 80C, with a quick recovery coil
that takes all the boilers output. A fast acting cylinder thermostat ensures
the boiler pumps heat into the cylinder ASAP with a recovery rate from cold
around 5-8 mins (Ariston claim 8 mins). The 80C water is blended down to
about 45-50C. e.g's, Ariston Genus 27 Plus, Glow Worm, Powermax, Alpha
CB50.

3) Infinately Continuous/Unvented cylinder combi -

An example being the Alpha CB50, a combination of both having a two stage
flowrate, of high flowrate when using the stored water with an automatic
flow regulator switching in to reduce flow to an invinately continuous
flowrate of approx 11 litres/min.
http://www.alpha-boilers.com/products/CB50.html

4) Heat Bank Combi -

Incoming water is instantly heated running through a plate heat exchanger
(as is most instantaneous combi's) that takes its heat from a "domestic hot
water only" store of water at approx 80C (instantaneous combi's take the
heat from a heat-exchanger heater via the burner). A fast acting thermostat
ensures the boiler pumps all of its heat into the store ASAP with a recovery
rate about 5-8 mins from cold. The 80C water is blended down to about
45-50C. They are generally two stage flow rates, in that when the thermal
store is exhausted it reverts to what the burner can produce, which is
approx 11-12 litre/minute. e.g. Vokera & Worcester floor standing models
(standard washing machine sizes).

N.B. The heat bank is a variation of a thermal store, but is "not" a thermal
store in the conventional sense in that a coil carrying cold mains water
runs though a store of hot water kept at about 80C. Heat-banks are far more
efficient and give higher flowrates than conventional coiled thermal stores.
The stainless steel plate heat-exchangers do not scale up so easily.

5) Combined Primary Storage Unit

(Not classed as a combi, but a derivative of a combi, but still a one box
solution, so still in the same family)

These are a combination of a large thermal store, or heat bank, and boiler
in one casing. The units are large (larger than standard washing machine
size) and floor mounted. The heating is taken off the thermal store, which
in many cases the DHW taken off the store using a plate heat-exchanger
(heat-bank). Unlike the Heat-bank in 3) above the thermal store supplies
heating "and" DHW, giving the "combined" to the title. They are available
from 1 to 2.5 bathroom models. Gledhill do an excellent condensing
version, the Gulfsream 2000. http://www.gledhill.net

Nos. 2), 3), 4) & 5) have high flowrates. No. 1 "generally" has low
flowrates but there are always exceptions and some can be high - e.g. the
ECO-Hometec infinitely continuous combi, actually has a very high flowrate.
Nos 2), 3), 4) & 5) use stored water, but in different ways. Unlike No. 1
"some" versions will eventually run cold, but that takes quite a time, hence
some are referred to as "two bathroom" models, having the ability to fill
two baths with very fast recovery rates. As hot water is being drawn off
the high rating burner is also reheating. Very rare do these combi's run
out of hot water in average use. When taking one shower the burner may be
re-heating faster than what can be drawn-off. No. 3) above uses stored
water but will not run out of hot water (high and low flowrates). Most
versions of No. 4) above are two stage flowrate models (high and low
flowrates) and will also not run out of hot water.

There are combi models that give hot water and heating simultaneously as
Combined Primary Storage Units do. Most don't as they are hot water
priority.

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much above
35kw.

40kW units are available from a number of makers. Some like Man do 76kW
one IIRC (you will need a pretty serious gas supply for that ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Fri, 07 Jan 2005 00:38:48 +0000, Markus Splenius
wrote:

Many thanks for the info IMM, I shall study it tomorrow - can't take
it all in now since I just got back from the pub! :-)

Basically what I want is a shower that nails you to the floor and a
bath that fills up in 3 minutes.

Then check specifications very carefully, particularly as regards
issues like two flow rates. Some of them are a con.

Boilers with some form of storage are able to deliver the volume of
hot water of the store initially - basically limited by mains flow
rate, and then the rate will fall to whatever the boiler can provide
on an instant basis, and that can be a great deal less.

A decent sized bath will take approximately 120 - 150 litres of water.
You would be hard pushed filling that from many mains supplies in 3
minutes anyway. A 39kW boiler (e.g. Worcester Greenstar will give
about 16 litres per minute of water at 40 degrees and winter mains
temperatures, so basically you would need a boiler or other
arrangement able to store a good 80 litres or so of hot water at 60
degrees or even higher to be able to mix with cold.

Remembe that it doesn't matter how sophisticated a system might appear
to be, it can't exceed the basic laws of physics....




M


On Thu, 6 Jan 2005 22:20:07 -0000, "IMM" wrote:


"Markus Splenius" wrote in message
. ..

What's the most powerful combi you can get? I haven't seen much above
35kw.



--

..andy

To email, substitute .nospam with .gl

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much above
35kw.

40kW units are available from a number of makers. Some like Man do 76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

I've had fitted an alpha cb50 for exactly those reasons and it fits the
bill perfectly

Shower will take your skin off, and bath fills v quickly with
scaldingly hot water (you can of course turn the thermostat down)

only drawback of converting from the old HW cylinder was that the new
pressurised system found lots of tiny leaks in the old radiators - so
I'm gradually replacing them

John

In article ,
Markus Splenius wrote:
Many thanks for the info IMM, I shall study it tomorrow - can't take
it all in now since I just got back from the pub! :-)

Basically what I want is a shower that nails you to the floor and a
bath that fills up in 3 minutes.

Then you definitely don't want a combi. To fill a bath in three minutes to
an adequate temperature in winter where the incoming mains water is cold
is a no no with a combi. You'll need a storage system. Which of course,
some combis incorporate, but then it's not truly a combi.

--
*Frankly, scallop, I don't give a clam

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

On Fri, 07 Jan 2005 08:51:09 +0000, Markus Splenius
wrote:

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much above
35kw.

40kW units are available from a number of makers. Some like Man do 76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

Around 60kW.

Don't forget that you have to allow for other appliances like hobs and
ovens in that, so practically maybe 50kW....





--

..andy

To email, substitute .nospam with .gl

On 7 Jan 2005 01:02:00 -0800, "Jape"
wrote:


only drawback of converting from the old HW cylinder was that the new
pressurised system found lots of tiny leaks in the old radiators - so
I'm gradually replacing them

Hmm, did you get lots of tiny leaks in the compression joints in the
pipework too? I wouldn't want to replace all my ground floor ceilings!
I suppose you can fit a valve to limit the pressure in the CH circuit?

M

On Thu, 6 Jan 2005 22:20:07 -0000, "IMM" wrote:

-- snipped description of combi boilers ---
1) The Infinitely Continuous Combi -

Heats cold mains water instantly as it runs through the combi. It never runs
out of hot water. This is the most common type of combi, generally having
lower flowrates than Nos 2 & 3 below. The largest flow rate instant combi is
a two bathroom model, 22 litres/min ECO-Hometec. Being a condenser it is
very economical too. http://www.eco-hometec.co.uk

Sorry to be pinikity but it's hard to compare the flowrate of the ECO
hometec range since they quote their flow rate at a lower temperature
rise of 30K rather than the normal 35K that other manufacturers use.
However the ECO 38 is likely to have a very good flow rate since it
has a power of 46kW. Their efficiency figures are also weird because
they use a figure of 110% to represent 100% efficiency!

Further more that are extremely expensive.

However I'm sure they are very good.

BTW: Worcester-Bosch do a 40kW Combi. Again they are quite expensive.
Once you go above 30-35kW the prices rise rapidly.

W.

"Dave Plowman (News)" wrote in message
...
In article ,
Markus Splenius wrote:
Many thanks for the info IMM, I shall study it tomorrow - can't take
it all in now since I just got back from the pub! :-)

Basically what I want is a shower that nails you to the floor and a
bath that fills up in 3 minutes.

Then you definitely don't want a combi.

Take no notice of this.

"Andy Hall" wrote in message
...
On Fri, 07 Jan 2005 08:51:09 +0000, Markus Splenius
wrote:

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much above
35kw.

40kW units are available from a number of makers. Some like Man do 76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

Around 60kW.

62.13 kW in fact. In reality you can go about 25% over that as the U6
meters have 100% overload. But private sharks Transco will only stick to
212 cu foot/hr and charge to uprate.

Don't forget that you have to allow for other appliances like hobs and
ovens in that, so practically maybe 50kW....

On Fri, 07 Jan 2005 11:23:42 +0000, W
wrote:

On Thu, 6 Jan 2005 22:20:07 -0000, "IMM" wrote:

-- snipped description of combi boilers ---
1) The Infinitely Continuous Combi -

Heats cold mains water instantly as it runs through the combi. It never runs
out of hot water. This is the most common type of combi, generally having
lower flowrates than Nos 2 & 3 below. The largest flow rate instant combi is
a two bathroom model, 22 litres/min ECO-Hometec. Being a condenser it is
very economical too. http://www.eco-hometec.co.uk

Sorry to be pinikity but it's hard to compare the flowrate of the ECO
hometec range since they quote their flow rate at a lower temperature
rise of 30K rather than the normal 35K that other manufacturers use.
However the ECO 38 is likely to have a very good flow rate since it
has a power of 46kW.

You can work out the results on the simple mass, specific heat and
temperature rise.

Their efficiency figures are also weird because
they use a figure of 110% to represent 100% efficiency!

Net figures as used elsewhere in Europe as opposed to the gross
figures used in the UK. Some people have difficulty understanding
the concept of latent heat unfortunately.


Further more that are extremely expensive.

Just good value for money.


However I'm sure they are very good.

Mmmm.



--

..andy

To email, substitute .nospam with .gl

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Fri, 07 Jan 2005 08:51:09 +0000, Markus Splenius
wrote:

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much above
35kw.

40kW units are available from a number of makers. Some like Man do 76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

Around 60kW.

62.13 kW in fact. In reality you can go about 25% over that as the U6
meters have 100% overload. But private sharks Transco will only stick to
212 cu foot/hr and charge to uprate.

Don't forget that you have to allow for other appliances like hobs and
ovens in that, so practically maybe 50kW....


A spec. is a spec.



--

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Fri, 07 Jan 2005 08:51:09 +0000, Markus Splenius
wrote:

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much
above
35kw.

40kW units are available from a number of makers. Some like Man do
76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

Around 60kW.

62.13 kW in fact. In reality you can go about 25% over that as the U6
meters have 100% overload. But private sharks Transco will only stick to
212 cu foot/hr and charge to uprate.

Don't forget that you have to allow for other appliances like hobs and
ovens in that, so practically maybe 50kW....


A spec. is a spec.

They changed the specs to suit themselves.

"W" wrote in message
...

BTW: Worcester-Bosch do a 40kW Combi.
Again they are quite expensive.
Once you go above 30-35kW the prices
rise rapidly.

Then you use two combi's. The outputs can be combined for the bath taps
using two check valves and a small shock arrestor after the valves. Check
with the makers first. Worcester say you can using the Juniors. This is
highly cost effective and you can get 50-60kW combined output using two
cheapish combi's. Mid range combi's are cheap as they are the bulk of the
combi market and are competitive.

Best to split the outputs of the combi's: one does one shower, one the
other, etc and combine the outlets for the bath. One can also do downstairs
and one upstairs giving easy and cheap zoning.

A few installers are now using this method as it solves many problems very
cheaply.

In article ,
IMM wrote:
Basically what I want is a shower that nails you to the floor and a
bath that fills up in 3 minutes.

Then you definitely don't want a combi.

Take no notice of this.

Perhaps you'd give the figures for a domestic combi that will fill a
standard bath with hot water in 3 minutes in winter? And of course, one
which doesn't store any water since that's no longer a true combi, but a
form of storage system...

Of course you can't, because such an animal doesn't exist.

Sad you didn't make a new year resolution to tell the truth and stop
peddling your usual misinformation.

--
*Okay, who stopped the payment on my reality check? *

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

I make a good living repairing combis. I have an open vented hot water cylinder at home and a regular boiler. You couldn't get me to put a combi in to replace that if you gave it me. I would actually think you were mad. If you offered as a means of filling a bath quickly another combi I would call for the men in white coats.

Thank goodness combis are so popular, I'm guaranteed work for many years to come.

Thank goodness I have enough intelligence to learn from other peoples mistakes and kept my airing cupboard.

Dave Plowman (News) wrote:


Perhaps you'd give the figures for a domestic combi that will fill a
standard bath with hot water in 3 minutes in winter? And of course, one
which doesn't store any water since that's no longer a true combi, but a
form of storage system...

Of course you can't, because such an animal doesn't exist.

Sad you didn't make a new year resolution to tell the truth and stop
peddling your usual misinformation.

Simple test fot the OP to try.

Time how long it takes to fill you bath from the cold tap alone with it
full on. If it is longer than three minutes then no amount of combi
power alone will do what you want. If the cold main is not up to the job
you will either need to upgrade it and/or accumulate water somewhere in
order to get the flow rate you desire.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
Basically what I want is a shower that nails you to the floor and a
bath that fills up in 3 minutes.

Then you definitely don't want a combi.

Take no notice of this.

Perhaps you'd give the

Read the other posts on this thread.

"John Rumm" wrote in message
...
Dave Plowman (News) wrote:


Perhaps you'd give the figures for a domestic combi that will fill a
standard bath with hot water in 3 minutes in winter? And of course, one
which doesn't store any water since that's no longer a true combi, but a
form of storage system...

Of course you can't, because such an animal doesn't exist.

Sad you didn't make a new year resolution to tell the truth and stop
peddling your usual misinformation.

Simple test fot the OP to try.

Time how long it takes to fill you bath from the cold tap alone with it
full on. If it is longer than three minutes then no amount of combi
power alone will do what you want. If the cold main is not up to the job
you will either need to upgrade it and/or accumulate water somewhere in
order to get the flow rate you desire.

The bath tap may not take all the mains flow.

On Fri, 07 Jan 2005 14:34:51 +0000, Andy Hall wrote:

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message
. ..
On Fri, 07 Jan 2005 08:51:09 +0000, Markus Splenius
wrote:

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much above
35kw.

40kW units are available from a number of makers. Some like Man do 76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

Around 60kW.

62.13 kW in fact. In reality you can go about 25% over that as the U6
meters have 100% overload. But private sharks Transco will only stick to
212 cu foot/hr and charge to uprate.

Don't forget that you have to allow for other appliances like hobs and
ovens in that, so practically maybe 50kW....


A spec. is a spec.

Precisely.

I think it's a bit like saying that you can get 16A from a 13A plug.
Which no doubt you can (since the fuse will likely not blow
for hours if at all). However on a hot day with a 99p 4-way
extension lead feeding a cheap plug that _claims_ to be BS 1363 and CE
approved (but is made and bought on cost for the sheds by Fook Yu of
China) you can expect trouble.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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 Fri, 7 Jan 2005 19:51:13 +0000, Paul Barker
wrote:


I make a good living repairing combis. I have an open vented hot water
cylinder at home and a regular boiler. You couldn't get me to put a
combi in to replace that if you gave it me. I would actually think you
were mad. If you offered as a means of filling a bath quickly another
combi I would call for the men in white coats.

Thank goodness combis are so popular, I'm guaranteed work for many
years to come.

Thank goodness I have enough intelligence to learn from other peoples
mistakes and kept my airing cupboard.

You should ask IMM for his mug (sorry customer) list. These people
have two combis so you could clean up.





--

..andy

To email, substitute .nospam with .gl

"Paul Barker" wrote in message
...

I make a good living repairing combis.

Ah a maitenance man! I can't see how you do as you don't understand the
benefits. There again changing fans and the likes doesn't take that much
knowledge of systems.

I have an open vented hot water
cylinder at home and a regular boiler.

You poor sod.

You couldn't get me to put a
combi in to replace that if you gave it me.

Don't understand the benefits eh?

I would actually think you
were mad. If you offered as
a means of filling a bath quickly another
combi I would call for the men in white coats.

Still don't understand the benefits eh?

Thank goodness combis are so popular,
I'm guaranteed work for many
years to come.

Just as well you don't design sytems for them, you wouldn't know were the
hell to fit one.

Thank goodness I have enough intelligence
to learn from other peoples
mistakes and kept my airing cupboard.

Boy the maintenance man doesn't know does he. You can fit a small rad at
the back to do the same job and store more clothes.

You must only repair the crappy ones. BTW, many people will say the exact
opposite to you who repair them on a daily basis.

If you want low presure showers (or have a a ridiculous noisy, expensive
power shower pump) and can't use most of your airing cupbiard then fine. Is
Fred Dibnah your hero? (bless him)

In case you didn't know. Most of the world laugh at our water sytems with
cylinders and tanks in the loft. They think we are mad. BTW, only the UK
and Ireland have the tank/cylinder setup.

For your info, as you should know, the difference between a system boiler
and a combi is negilible these days in complexity.

Read my posts on using two combi's and the combi explainations, I'm you
didn't know. If you know anything about system design you will conclude it
is the cheapest approach to acheive zoning, full main pressure and no airing
cuboards that look like a school boiler house. Do you hang your underwear
off the CH pump? Many do.

"Ed Sirett" wrote in message
n.co.uk...
On Fri, 07 Jan 2005 14:34:51 +0000, Andy Hall wrote:

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message
. ..
On Fri, 07 Jan 2005 08:51:09 +0000, Markus Splenius
wrote:

On Fri, 07 Jan 2005 01:09:32 +0000, John Rumm
wrote:

Markus Splenius wrote:

What's the most powerful combi you can get? I haven't seen much
above
35kw.

40kW units are available from a number of makers. Some like Man do
76kW
one IIRC (you will need a pretty serious gas supply for that ;-)

What are the limitations of a "standard" gas supply? I have a 3
bedroom detached house.

M.

Around 60kW.

62.13 kW in fact. In reality you can go about 25% over that as the U6
meters have 100% overload. But private sharks Transco will only stick
to
212 cu foot/hr and charge to uprate.

Don't forget that you have to allow for other appliances like hobs and
ovens in that, so practically maybe 50kW....


A spec. is a spec.

Precisely.

I think it's a bit like saying that you can get 16A from a 13A plug.
Which no doubt you can (since the fuse will likely not blow
for hours if at all).

Balls!!! I used to design gas systems in the 70s. U6 meters have an 100%
overload. We would take them up to 350 cu foot an hour. Go to your meter.
Take off the outlet pipe and fit a 1" hose to outside, then turn on the
maintap. Time the dial for 30 secs or a minute. See how much gas it then
passes for an hour. I bet it is more than 212 cu foot an hour.

On Fri, 7 Jan 2005 22:43:31 -0000, "IMM" wrote:


"Ed Sirett" wrote in message
on.co.uk...
On Fri, 07 Jan 2005 14:34:51 +0000, Andy Hall wrote:

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message

A spec. is a spec.

Precisely.

I think it's a bit like saying that you can get 16A from a 13A plug.
Which no doubt you can (since the fuse will likely not blow
for hours if at all).

Balls!!! I used to design gas systems in the 70s.

Perhaps you could let us know where so that Transco can be called to
correct the errors.

U6 meters have an 100%
overload.

With full accuracy and full lifetime?

We would take them up to 350 cu foot an hour.

Nearly double the specified rating? Was this official gas board
policy?

Go to your meter.
Take off the outlet pipe and fit a 1" hose to outside, then turn on the
maintap. Time the dial for 30 secs or a minute. See how much gas it then
passes for an hour. I bet it is more than 212 cu foot an hour.

That it may, but it does not mean that it is correct engineering
practice.












--

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Fri, 7 Jan 2005 22:43:31 -0000, "IMM" wrote:


"Ed Sirett" wrote in message
on.co.uk...
On Fri, 07 Jan 2005 14:34:51 +0000, Andy Hall wrote:

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message

A spec. is a spec.

Precisely.

I think it's a bit like saying that you can get 16A from a 13A plug.
Which no doubt you can (since the fuse will likely not blow
for hours if at all).

Balls!!! I used to design gas systems in the 70s.

Perhaps you could let us know where so that Transco can be called to
correct the errors.

U6 meters have an 100%
overload.

With full accuracy and full lifetime?

They could run at 100% over for a very long time. I forget the figures now.

We would take them up to 350 cu foot an hour.

Nearly double the specified rating? Was this official gas board
policy?

Yep.

Go to your meter.
Take off the outlet pipe and fit a 1" hose to outside, then turn on the
maintap. Time the dial for 30 secs or a minute. See how much gas it
then
passes for an hour. I bet it is more than 212 cu foot an hour.

That it may, but it does not mean that
it is correct engineering practice.

It was in the 1970s. Now private rip off artists like Transco make you pay
when there is no need to.

If I recall rightly. There was:

1. 100 cu ft/hr (3/4" connections. known as 5 light connections because it
could only take 5 lights in Victorian times on town gas. The term is still
used)

2. 250 cu ft/hr (1" connections. known as 10 light connections)

3. 400 cu ft/hr (1" connections. known as 10 light connections)

4. 800 cu ft/hr (1 1/4" connections. known as 20 or 30 light connections I
think [all vague now])

They were all replaced with only two meters:

1. U6 (6 cu meters/hr) 212 cu ft/hr (1" connections. known as 10 light
connections)

2. U16. (16 cu metres/hr) 560 cu ft/hr (1 1/4" connections)

We fitted U6s for less than 350 cu foot/hr and U16 for above. The U16, if I
recall rightly, we fitted for up to 800 cu ft/hr.

If a premises required less than 100 cu ft/hr. we left in the old 3/4" iron
mains pipe. If above 1" was used. A U16 meter required a 1 1/4" mains
pipe. The exception were there was a very pressure gas main. Some roads
had very pressure trunk mains that fed a district, and was governed down
normal pressure. If a hosue was on this mains pipe special high pressure
meter regulators, with a blow-off to outside, were installed and a U16 may
have been OK with a 1" mains pipe.

All from memory, so may not be 100% right.

In article ,
IMM wrote:
Balls!!! I used to design gas systems in the 70s.

That's why they brought in the CORGI registration, then?

--
*Procrastination is the art of keeping up with yesterday.

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

On Fri, 7 Jan 2005 23:54:40 -0000, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Fri, 7 Jan 2005 22:43:31 -0000, "IMM" wrote:


"Ed Sirett" wrote in message
on.co.uk...
On Fri, 07 Jan 2005 14:34:51 +0000, Andy Hall wrote:

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message

A spec. is a spec.

Precisely.

I think it's a bit like saying that you can get 16A from a 13A plug.
Which no doubt you can (since the fuse will likely not blow
for hours if at all).

Balls!!! I used to design gas systems in the 70s.

Perhaps you could let us know where so that Transco can be called to
correct the errors.

U6 meters have an 100%
overload.

With full accuracy and full lifetime?

They could run at 100% over for a very long time. I forget the figures now.

I imagine that you did then as well by the look of it.


We would take them up to 350 cu foot an hour.

Nearly double the specified rating? Was this official gas board
policy?

Yep.

No wonder they were shut down.


Go to your meter.
Take off the outlet pipe and fit a 1" hose to outside, then turn on the
maintap. Time the dial for 30 secs or a minute. See how much gas it
then
passes for an hour. I bet it is more than 212 cu foot an hour.

That it may, but it does not mean that
it is correct engineering practice.

It was in the 1970s. Now private rip off artists like Transco make you pay
when there is no need to.

It seems that they are delivering and using equipment within
specification. Ownership has no relevance to that.



If I recall rightly. There was:

1. 100 cu ft/hr (3/4" connections. known as 5 light connections because it
could only take 5 lights in Victorian times on town gas. The term is still
used)

You did say the *19* 70s when you were doing these design bodges?



2. 250 cu ft/hr (1" connections. known as 10 light connections)

3. 400 cu ft/hr (1" connections. known as 10 light connections)

4. 800 cu ft/hr (1 1/4" connections. known as 20 or 30 light connections I
think [all vague now])

They were all replaced with only two meters:

1. U6 (6 cu meters/hr) 212 cu ft/hr (1" connections. known as 10 light
connections)

2. U16. (16 cu metres/hr) 560 cu ft/hr (1 1/4" connections)

We fitted U6s for less than 350 cu foot/hr and U16 for above. The U16, if I
recall rightly, we fitted for up to 800 cu ft/hr.

If a premises required less than 100 cu ft/hr. we left in the old 3/4" iron
mains pipe. If above 1" was used. A U16 meter required a 1 1/4" mains
pipe. The exception were there was a very pressure gas main. Some roads
had very pressure trunk mains that fed a district, and was governed down
normal pressure. If a hosue was on this mains pipe special high pressure
meter regulators, with a blow-off to outside, were installed and a U16 may
have been OK with a 1" mains pipe.

All from memory, so may not be 100% right.


I just wonder how much of this bodged up infrastructure is still in
place. It seems that one of the less palatable sides of a public
monopoly organisation is to make up its own rules as it goes along
with the customer having no knowledge or choice in the potential
danger or billing error that may have been introduced.

I would much rather have a choice of organisations implementing a
defined specification.....



--

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Fri, 7 Jan 2005 23:54:40 -0000, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Fri, 7 Jan 2005 22:43:31 -0000, "IMM" wrote:


"Ed Sirett" wrote in message
on.co.uk...
On Fri, 07 Jan 2005 14:34:51 +0000, Andy Hall wrote:

On Fri, 7 Jan 2005 12:57:13 -0000, "IMM" wrote:


"Andy Hall" wrote in message

A spec. is a spec.

Precisely.

I think it's a bit like saying that you can get 16A from a 13A plug.
Which no doubt you can (since the fuse will likely not blow
for hours if at all).

Balls!!! I used to design gas systems in the 70s.

Perhaps you could let us know where so that Transco can be called to
correct the errors.

U6 meters have an 100%
overload.

With full accuracy and full lifetime?

They could run at 100% over for a very long time. I forget the figures
now.

I imagine that you did then as well by the look of it.


We would take them up to 350 cu foot an hour.

Nearly double the specified rating? Was this official gas board
policy?

Yep.

No wonder they were shut down.


Go to your meter.
Take off the outlet pipe and fit a 1" hose to outside, then turn on
the
maintap. Time the dial for 30 secs or a minute. See how much gas it
then
passes for an hour. I bet it is more than 212 cu foot an hour.

That it may, but it does not mean that
it is correct engineering practice.

It was in the 1970s. Now private rip off artists like Transco make you
pay
when there is no need to.

It seems that they are delivering and using equipment within
specification. Ownership has no relevance to that.



If I recall rightly. There was:

1. 100 cu ft/hr (3/4" connections. known as 5 light connections because
it
could only take 5 lights in Victorian times on town gas. The term is
still
used)

You did say the *19* 70s when you were doing these design bodges?



2. 250 cu ft/hr (1" connections. known as 10 light connections)

3. 400 cu ft/hr (1" connections. known as 10 light connections)

4. 800 cu ft/hr (1 1/4" connections. known as 20 or 30 light connections
I
think [all vague now])

They were all replaced with only two meters:

1. U6 (6 cu meters/hr) 212 cu ft/hr (1" connections. known as 10 light
connections)

2. U16. (16 cu metres/hr) 560 cu ft/hr (1 1/4" connections)

We fitted U6s for less than 350 cu foot/hr and U16 for above. The U16,
if I
recall rightly, we fitted for up to 800 cu ft/hr.

If a premises required less than 100 cu ft/hr. we left in the old 3/4"
iron
mains pipe. If above 1" was used. A U16 meter required a 1 1/4" mains
pipe. The exception were there was a very pressure gas main. Some roads
had very pressure trunk mains that fed a district, and was governed down
normal pressure. If a hosue was on this mains pipe special high pressure
meter regulators, with a blow-off to outside, were installed and a U16
may
have been OK with a 1" mains pipe.

All from memory, so may not be 100% right.


I just wonder how much of this bodged up infrastructure is still in
place.

You wouldn't know a bodged up job if you fell on one. Why do you persist in
making a part of yourself?


It seems that one of the less palatable
sides of a public monopoly organisation
is to make up its own rules as it goes along
with the customer having no knowledge or
choice in the potential danger or billing
error that may have been introduced.

Stop babbling crap!

I would much rather have a choice of organisations implementing a
defined specification.....

Yep that is what they did, as stated above.

On Sat, 8 Jan 2005 01:26:53 -0000, "IMM" wrote:


"Andy Hall" wrote in message

I just wonder how much of this bodged up infrastructure is still in
place.

You wouldn't know a bodged up job if you fell on one. Why do you persist in
making a part of yourself?


It seems that one of the less palatable
sides of a public monopoly organisation
is to make up its own rules as it goes along
with the customer having no knowledge or
choice in the potential danger or billing
error that may have been introduced.

Stop babbling crap!

I would much rather have a choice of organisations implementing a
defined specification.....

Yep that is what they did, as stated above.



So please explain why it's OK for a public monopoly organisation to
exceed the manufacturers specifications on products that it uses - if
indeed it did on a widespread basis, but that it's not when its
replacement organisations does installations within those
specifications.

Did you get fired for incompetence?

If the manufacturers intended their meters to run as a design goal at
50% over stated capacity, they would rate them that way.
Alternatively, they would manufacture them down to the stated spec.
with much less headroom and more cheaply.

If there is overdesign on the part of the manufacturers it is for
reasons of a safety or accuracy purpose.

It doesn't seem very plausible that they will have sat down one day
and thought "Now there's that bodger, IMM, at the gas board and we
know he's going to use the meter at 50% more than the spec allows, so
we'd better overdesign it and not tell him"

More likely they will have thought "We'd better put a warning note
with pictures in every box warning him not to use a hacksaw to install
it".






--

..andy

To email, substitute .nospam with .gl

In article ,
IMM wrote:
I just wonder how much of this bodged up infrastructure is still in
place.

You wouldn't know a bodged up job if you fell on one. Why do you
persist in making a part of yourself?

Are you trying to do a hacksaw job on Andy?

--
*I don't have a license to kill, but I do have a learner's permit.

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

"Andy Hall" wrote in message
...
On Sat, 8 Jan 2005 01:26:53 -0000, "IMM" wrote:


"Andy Hall" wrote in message

I just wonder how much of this bodged up infrastructure is still in
place.

You wouldn't know a bodged up job if you fell on one. Why do you persist
in
making a part of yourself?


It seems that one of the less palatable
sides of a public monopoly organisation
is to make up its own rules as it goes along
with the customer having no knowledge or
choice in the potential danger or billing
error that may have been introduced.

Stop babbling crap!

I would much rather have a choice of organisations implementing a
defined specification.....

Yep that is what they did, as stated above.

So please explain why it's OK for
a public monopoly organisation to
exceed the manufacturers specifications
on products that it uses

The makers stated overload was fine. When privatisation comes along, there
is none and the punter pays through the nose. As time went on and houses
became insulated and boilers more efficient using less gas, overload was far
less of a problem.

Did you get fired for incompetence?

They wanted to keep me on and gave shining references.

If the manufacturers intended their meters to run as a design goal at
50% over stated capacity, they would rate them that way.

How do you know?

If there is overdesign on the part of the manufacturers it is for
reasons of a safety or accuracy purpose.

If I recall, the meters were not recommended to operate at 100% overload at
100% of the time. A domestic boiler is intermittent in operation, and
modern boilers modulate down, meaning meter overload is even more feasible
these days.

snip babble from a man who doesn't know

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
I just wonder how much of this bodged up infrastructure is still in
place.

You wouldn't know a bodged up job if you fell on one. Why do you
persist in making a prat of yourself?

Are you trying to do a hacksaw job on Andy?

At times he does required ad-hoc surgery.

"IMM" wrote in message
...

"Andy Hall" wrote in message
...
On Sat, 8 Jan 2005 01:26:53 -0000, "IMM" wrote:


"Andy Hall" wrote in message


Did you get fired for incompetence?

They wanted to keep me on and gave shining references.

eye eye

Jim A

On Sat, 8 Jan 2005 11:08:37 -0000, "IMM" wrote:




The makers stated overload was fine.

Really? In writing?


When privatisation comes along, there
is none and the punter pays through the nose. As time went on and houses
became insulated and boilers more efficient using less gas, overload was far
less of a problem.

I see. Here comes the fudge.



Did you get fired for incompetence?

They wanted to keep me on and gave shining references.

I guess something along the lines of:

"IMM worked for us for 20 years, during which time he was seldom
late".



If the manufacturers intended their meters to run as a design goal at
50% over stated capacity, they would rate them that way.

How do you know?

If there is overdesign on the part of the manufacturers it is for
reasons of a safety or accuracy purpose.

If I recall, the meters were not recommended to operate at 100% overload at
100% of the time.

The subtle change of tune.


A domestic boiler is intermittent in operation, and
modern boilers modulate down, meaning meter overload is even more feasible
these days.

Accompanied by more fudge.

It's getting very sweet and sticky here.....






--

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Sat, 8 Jan 2005 11:08:37 -0000, "IMM" wrote:




The makers stated overload was fine.

Really? In writing?

We had it in writing from the gas boards. Tables etc.

When privatisation comes along, there
is none and the punter pays through the nose. As time went on and houses
became insulated and boilers more efficient using less gas, overload was
far
less of a problem.

I see. Here comes the fudge.



Did you get fired for incompetence?

They wanted to keep me on and gave shining references.

I guess something along the lines of:

"IMM worked for us for 20 years, during which time he was seldom
late".



If the manufacturers intended their meters to run as a design goal at
50% over stated capacity, they would rate them that way.

How do you know?

If there is overdesign on the part of the manufacturers it is for
reasons of a safety or accuracy purpose.

If I recall, the meters were not recommended
to operate at 100% overload at
100% of the time.

The subtle change of tune.

No. They could operate at 100% overload, but 100% of the time. Very clear.
One would not be fitted to a commercial installation that ran at 100% over
24/7. For domestic it was fine. Got it? Read again if you haven't.

A domestic boiler is intermittent in operation, and
modern boilers modulate down, meaning meter
overload is even more feasible these days.

Accompanied by more fudge.

As you are hard of thinking, these days overload would be minimal compared
to 25 years ago. But the private sharks will still not accomodate it.

In article ,
IMM wrote:
No. They could operate at 100% overload, but 100% of the time. Very
clear. One would not be fitted to a commercial installation that ran at
100% over 24/7. For domestic it was fine. Got it? Read again if you
haven't.

Have done and it's still rubbish.

--
*According to my calculations, the problem doesn't exist.

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