We moved into our house 7 months ago. It has a gloworm back boiler at the moment (it's old but not sure how old). Having a new central heating system and all new rads and pipework. It's a fairly large detached house, 2 double bedrooms and 1 large double bedroom, 1 bathroom and a downstairs wc. We have 10 rads at the moment but will need 11. The immersion and water tank are in the bathroom but if we keep them we would create more room in the bathroom and move the immersion to one of the bedrooms and the water tank to the loft. I've spent ages on the internet looking at different boilers and systems but cannot decide. We've had quotes for combi's, unvented cylinders and heat only boilers, the quotes being from £2500 to £6000 from various plumbers, the combi being the cheapest. We've decided which plumber we are having (has a very good reputation). Would like advice on what people think would be best system and which boiler to have.

We need more information about your expected water usage. In particular, we
need to know:

1. How many people live there?
2. How many teenage daughters? (better not publish your address though!)
3. Does anyone in the house prefer baths?
4. Does anyone like having long showers?
5. Are you likely to add an additional bathroom, in a loft
conversion/extension, say?
6. What is the maximum flow from your kitchen tap? (measure with bucket and
timer)
7. Is your electricity supply reliable?
8. Is cost a major factor?

There are several possible solutions. The answers to the above questions
will determine the best solution for you. Some possible suggestions a

1. Instantaneous combi. The cheapest solution will provide unlimited length
showers of good quality. Requires about 20lpm from the mains water supply.
Bath filling will be slow. Temperature regulation will be poor, but not a
problem if the shower mixer is chosen carefully. It will be the most energy
efficient, assuming similar boiler types.

2. Unvented cylinder. This will be the most expensive solution. It will
provide oodles of hot water at mains pressure, enough to drive the largest
and most obscene panel shower with body jets. It will require yearly
maintenance to ensure continued safety. It will fill a bath as rapidly as
the water can enter your house down the supply pipe.

3. Heat bank. This will cost a fraction less than the unvented cylinder.
Purchase costs are similar, but installation is simpler. It will also
provide mains pressure hot water, but flow rates might be slightly limited
if your mains water supply is really strong. It will still fill a bath in 3
minutes, so this isn't a problem. It is inherently safer than an unvented
cylinder, reducing the need for maintenance, but might be slightly less
energy efficient, as the condensing boiler may need to run at a higher
temperature. Some installers will not have heard of them, and so may refuse
to fit them. The hot water is never stored in this type of system, meaning
that the hot tap provides drinking water (unless you have a water softener).
This can be useful when filling kettles/saucepans, if you're not a patient
type.

4. Conventional gravity system. This will be cheaper than the mains pressure
options. It is a good system when the mains water supply is poor. When pump
assisted, it can provide excellent shower and bath filling performance, as
the expense of noise and pump maintenance implications. It requires a large
cold cistern in the loft, which can be problematic if it is decided to have
a loft conversion, or the loft space is not suitable for other reasons.

Some combi boilers work on the principle of (2) and (3) above, but with
small stores. They can be useful in some situations, particularly when space
is limited. However, they can be expensive, often more so than the full
sized discrete systems they emulate.

Christian.

On Mon, 10 Jan 2005 10:10:47 -0000, "Christian McArdle"
wrote:

We need more information about your expected water usage. In particular, we
need to know:

1. How many people live there?
2. How many teenage daughters? (better not publish your address though!)


Teenage sons are worse - once they discover girls.......



--

..andy

To email, substitute .nospam with .gl

Thanks for that. Some more info for you.

There are 2 of us, no children (at the moment).
Mainly shower, occasional baths. Fairly long showers.
Would maybe add an ensuite shower, but that wouldn't be yet.
Flow from tap approx 21 lpm.
Electricity supply has been reliable so far.
We would fit the rads and pipework ourselves and get the plumber to do the boiler. Around £1500 (maybe a little bit more) to spend on boiler inc fitting.

Sam

We would fit the rads and pipework ourselves and get the plumber to do
the boiler. Around £1500 (maybe a little bit more) to spend on boiler
inc fitting.

OK, if you're happy doing the radiators, you'd be happy fitting a heat bank.
It is plumbed in just like a radiator, but with additional mains cold in and
hot water out. It is much more suited to quick DIY installations than a
mains pressure cylinder, which has to have all sorts of additional safety
equipment, pressure relief runs etc.

So, I would narrow your choices to a high flow combi and a heat bank system.
Something like:

Worcester Bosch HE35+ for 1140 inc VAT. (instant combi)

or

DPS Pandora + Worcester Bosch HE28 for around 1500 inc VAT total.

You'll need to budget a few hundred to get a CORGI round to install the
gas/flue, if you're not happy to describe yourself as competent for these
tasks. You'll need more if it requires a new gas run.

Note that you won't get the full benefit of the heat bank at only 21lpm,
although it will still be noticeably quicker than the combi and less prone
to temperature fluctuation. However, you may find that after rejigging, the
total throughput of water in the house actually exceeds 21lpm anyway.
Kitchen taps often aren't as wide bored as they used to be and you can find
the bathroom taps, with their twin wider passages can pass more water.

If you are replumbing the house, consider replacing all cold water pipework
with 22mm bore (except runs to toilets and basins). Provided pressure is
high enough, I'd then use 15mm for hot water pipework between tank and
kitchen and either 15mm or 22mm from tank to bathroom, remembering that
there will be more wastage and longer lead times if 22mm is used, although
it might marginally increase flow rate.

Christian.

On Mon, 10 Jan 2005 17:02:40 -0000, "Christian McArdle"
wrote:

We would fit the rads and pipework ourselves and get the plumber to do
the boiler. Around £1500 (maybe a little bit more) to spend on boiler
inc fitting.

OK, if you're happy doing the radiators, you'd be happy fitting a heat bank.
It is plumbed in just like a radiator, but with additional mains cold in and
hot water out. It is much more suited to quick DIY installations than a
mains pressure cylinder, which has to have all sorts of additional safety
equipment, pressure relief runs etc.

So, I would narrow your choices to a high flow combi and a heat bank system.
Something like:

Worcester Bosch HE35+ for 1140 inc VAT. (instant combi)


or

DPS Pandora + Worcester Bosch HE28 for around 1500 inc VAT total.

I would have though this would be more like £1750, depending on the
options fitted to the Pandora.

I think a heat bank is OTT for this application. I'm sure the cheaper
solution would be fine (combi).

Mark

DPS Pandora + Worcester Bosch HE28 for around 1500 inc VAT total.

I would have though this would be more like £1750, depending on the
options fitted to the Pandora.

It is what I paid for exactly that system. The boiler has since dropped
around 20 quid. I got the impression that I could have got the Pandora
cheaper if I improved my non-existent negotiating skills.

Christian.

On Mon, 10 Jan 2005 10:10:47 +0000, Christian McArdle wrote:

We need more information about your expected water usage. In particular, we
need to know:

1. How many people live there?
2. How many teenage daughters? (better not publish your address though!)
3. Does anyone in the house prefer baths?
4. Does anyone like having long showers?
5. Are you likely to add an additional bathroom, in a loft
conversion/extension, say?
6. What is the maximum flow from your kitchen tap? (measure with bucket and
timer)
7. Is your electricity supply reliable?
8. Is cost a major factor?

There are several possible solutions. The answers to the above questions
will determine the best solution for you. Some possible suggestions a

1. Instantaneous combi. The cheapest solution will provide unlimited length
showers of good quality. Requires about 20lpm from the mains water supply.
Bath filling will be slow. Temperature regulation will be poor, but not a
problem if the shower mixer is chosen carefully. It will be the most energy
efficient, assuming similar boiler types.

2. Unvented cylinder. This will be the most expensive solution. It will
provide oodles of hot water at mains pressure, enough to drive the largest
and most obscene panel shower with body jets. It will require yearly
maintenance to ensure continued safety. It will fill a bath as rapidly as
the water can enter your house down the supply pipe.

3. Heat bank. This will cost a fraction less than the unvented cylinder.
Purchase costs are similar, but installation is simpler. It will also
provide mains pressure hot water, but flow rates might be slightly limited
if your mains water supply is really strong. It will still fill a bath in 3
minutes, so this isn't a problem. It is inherently safer than an unvented
cylinder, reducing the need for maintenance, but might be slightly less
energy efficient, as the condensing boiler may need to run at a higher
temperature. Some installers will not have heard of them, and so may refuse
to fit them. The hot water is never stored in this type of system, meaning
that the hot tap provides drinking water (unless you have a water softener).
This can be useful when filling kettles/saucepans, if you're not a patient
type.

4. Conventional gravity system. This will be cheaper than the mains pressure
options. It is a good system when the mains water supply is poor. When pump
assisted, it can provide excellent shower and bath filling performance, as
the expense of noise and pump maintenance implications. It requires a large
cold cistern in the loft, which can be problematic if it is decided to have
a loft conversion, or the loft space is not suitable for other reasons.

Some combi boilers work on the principle of (2) and (3) above, but with
small stores. They can be useful in some situations, particularly when space
is limited. However, they can be expensive, often more so than the full
sized discrete systems they emulate.


It's refreshing to see a good range of options listed with the strengths
and weaknesses listed instead of a one-size-fits all slanging match.


--
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

"Ed Sirett" wrote in message
news
SNIP



It's refreshing to see a good range of options listed with the strengths
and weaknesses listed instead of a one-size-fits all slanging match.


YET! g

"Christian McArdle" wrote in message
. net...
We need more information about your expected water usage. In particular,
we
need to know:

1. How many people live there?
2. How many teenage daughters? (better not publish your address though!)
3. Does anyone in the house prefer baths?
4. Does anyone like having long showers?
5. Are you likely to add an additional bathroom, in a loft
conversion/extension, say?
6. What is the maximum flow from your kitchen tap? (measure with bucket
and
timer)
7. Is your electricity supply reliable?
8. Is cost a major factor?

There are several possible solutions. The answers to the above questions
will determine the best solution for you. Some possible suggestions a

1. Instantaneous combi. The cheapest
solution will provide unlimited length
showers of good quality. Requires about
20lpm from the mains water supply.
Bath filling will be slow.

Not true - misinformation. Old wives tales. Some models fill baths as fast
as a conventional cylinder.

Temperature regulation will be
poor,

Not true - misinformation. Old wives tales. On some models it is very
good. This section is misleading as it is so sparse.

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
CD50.

3) Infinately Continuous/Unvented cylinder combi -

An example being the Alpha CD50, 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 infinately continuous
flowrate of approx 13-14 litres/min.
http://www.alpha-boilers.com/products/CD50.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.

2. Unvented cylinder. This will be the most expensive solution. It will
provide oodles of hot water at mains pressure, enough to drive the largest
and most obscene panel shower with body jets. It will require yearly
maintenance to ensure continued safety. It will fill a bath as rapidly as
the water can enter your house down the supply pipe.

Not so. They are reduced in pressure, whiuch can restrict the flowrate.

3. Heat bank. This will cost a fraction less than the unvented cylinder.
Purchase costs are similar, but installation is simpler. It will also
provide mains pressure hot water, but flow rates might be slightly limited
if your mains water supply is really strong. It will still fill a bath in
3
minutes, so this isn't a problem. It is inherently safer than an unvented
cylinder, reducing the need for maintenance, but might be slightly less
energy efficient, as the condensing boiler may need to run at a higher
temperature. Some installers will not have heard of them, and so may
refuse
to fit them. The hot water is never stored in this type of system, meaning
that the hot tap provides drinking water (unless you have a water
softener).
This can be useful when filling kettles/saucepans, if you're not a patient
type.

4. Conventional gravity system. This will be cheaper
than the mains pressure options.

Nor so. This can be much more expensive than a combi system as a tank is
in the loft, cylinder, etc, complete with a large amount of pipe and
fittings

It is a good system when the mains water supply is poor. When pump
assisted, it can provide excellent shower and bath filling performance, as
the expense of noise and pump maintenance implications. It requires a
large
cold cistern in the loft, which can be problematic if it is decided to
have
a loft conversion, or the loft space is not suitable for other reasons.

That's better.

"Andy Hall" wrote in message
...
On Mon, 10 Jan 2005 10:10:47 -0000, "Christian McArdle"
wrote:

We need more information about your expected water usage. In particular,
we
need to know:

1. How many people live there?
2. How many teenage daughters? (better not publish your address though!)

Teenage sons are worse - once they discover girls.......

.....and booze and football. They sceam in their sleep, get your tits out
for the lads.

"Ed Sirett" wrote in message
news
On Mon, 10 Jan 2005 10:10:47 +0000, Christian McArdle wrote:

We need more information about your expected water usage. In particular,
we
need to know:

1. How many people live there?
2. How many teenage daughters? (better not publish your address though!)
3. Does anyone in the house prefer baths?
4. Does anyone like having long showers?
5. Are you likely to add an additional bathroom, in a loft
conversion/extension, say?
6. What is the maximum flow from your kitchen tap? (measure with bucket
and
timer)
7. Is your electricity supply reliable?
8. Is cost a major factor?

There are several possible solutions. The answers to the above questions
will determine the best solution for you. Some possible suggestions a

1. Instantaneous combi. The cheapest solution will provide unlimited
length
showers of good quality. Requires about 20lpm from the mains water
supply.
Bath filling will be slow. Temperature regulation will be poor, but not
a
problem if the shower mixer is chosen carefully. It will be the most
energy
efficient, assuming similar boiler types.

2. Unvented cylinder. This will be the most expensive solution. It will
provide oodles of hot water at mains pressure, enough to drive the
largest
and most obscene panel shower with body jets. It will require yearly
maintenance to ensure continued safety. It will fill a bath as rapidly
as
the water can enter your house down the supply pipe.

3. Heat bank. This will cost a fraction less than the unvented cylinder.
Purchase costs are similar, but installation is simpler. It will also
provide mains pressure hot water, but flow rates might be slightly
limited
if your mains water supply is really strong. It will still fill a bath
in 3
minutes, so this isn't a problem. It is inherently safer than an
unvented
cylinder, reducing the need for maintenance, but might be slightly less
energy efficient, as the condensing boiler may need to run at a higher
temperature. Some installers will not have heard of them, and so may
refuse
to fit them. The hot water is never stored in this type of system,
meaning
that the hot tap provides drinking water (unless you have a water
softener).
This can be useful when filling kettles/saucepans, if you're not a
patient
type.

4. Conventional gravity system. This will be cheaper than the mains
pressure
options. It is a good system when the mains water supply is poor. When
pump
assisted, it can provide excellent shower and bath filling performance,
as
the expense of noise and pump maintenance implications. It requires a
large
cold cistern in the loft, which can be problematic if it is decided to
have
a loft conversion, or the loft space is not suitable for other reasons.

Some combi boilers work on the principle of (2) and (3) above, but with
small stores. They can be useful in some situations, particularly when
space
is limited. However, they can be expensive, often more so than the full
sized discrete systems they emulate.


It's refreshing to see a good range of options listed with the strengths
and weaknesses listed instead of a one-size-fits all slanging match.

You are having a laugh of course.

The message
from "IMM" contains these words:

Not true

snip dIMMS dishonest drivel.

--
Roger

"Roger" wrote in message
k...
The message
from "IMM" contains these words:

Not true


snip drivel

The message
from "IMM" contains these words:

Not true


snip drivel

That's more like it. dIMM has at last snipped dIMMs dishonest drivel.

--
Roger

"Roger" wrote in message
k...
The message
from "IMM" contains these words:

Not true


snip drivel

That's

snip drivel

The message
from "IMM" contains these words:



snip drivel


And again dIMM snips dIMMs dishonest drivel.

--
Roger

"Roger" wrote in message
k...
The message
from "IMM" contains these words:

snip drivel

And

snip drivel