We've decided to abandon our major heating overhaul, until such time as
our kitchen needs re-doing - otherwise kitchen would nee major work and
we would need to demolish a chimney and re-site the boiler, which is a
major PITA given the access problems we have. Would also have real
problems siting the consending pipe for a new boiler

As a short-medium term solution, we were thinking of keeping the
current Thorn floorstanding boiler (touch wood, it's 20 years old but
it works fine) and replacing the standard copper cylinder with a fast
recovery one, like an Albion superduty. Plumbcentre also do one called
a Centercyl.

The current problem is that in depths of winter, two people can't
shower as hot water runs out (its a 36 * 18 copper cylinder). It's a
pumped shower. Will a fast recovery make much of a difference. Max BTU
of boiler is 40,000.

Also, is =A3350 a decent price to change the cylinder - including a
flush through and new inhibitor.=20

Thanks

KS

On 18 Apr 2005 04:20:54 -0700, "KS" wrote:

We've decided to abandon our major heating overhaul, until such time as
our kitchen needs re-doing - otherwise kitchen would nee major work and
we would need to demolish a chimney and re-site the boiler, which is a
major PITA given the access problems we have. Would also have real
problems siting the consending pipe for a new boiler

As a short-medium term solution, we were thinking of keeping the
current Thorn floorstanding boiler (touch wood, it's 20 years old but
it works fine) and replacing the standard copper cylinder with a fast
recovery one, like an Albion superduty. Plumbcentre also do one called
a Centercyl.

The current problem is that in depths of winter, two people can't
shower as hot water runs out (its a 36 * 18 copper cylinder). It's a
pumped shower. Will a fast recovery make much of a difference. Max BTU
of boiler is 40,000.

This is approx. a 10kW boiler (BTUs are deprecated units :-) )

If it is currently connected via gravity circulation and not pumped,
then converting to pumped would help and pumped with the larger coil
area a little more.

However, the first fundamental problem is that the boiler is too small
to take much advantage of a fast recovery cylinder - they can usually
take at least 20kW.

The second is that the cylinder is too small. Even if you could
take all of the output of the boiler, 10kW will not produce anything
close to the amount of heat required to reheat the water fast enough.
If you were able to heat it at a rate of 20-30kW by having a larger
boiler, you could possibly get away with this size.

Given that you don't want to change the boiler right now, since you
are replacing the cylinder, then going for a 160 or even 180 litre
fast recovery one would be the way around this problem. The
footprint is the same, just higher.


Also, is £350 a decent price to change the cylinder - including a
flush through and new inhibitor.




--

..andy

To email, substitute .nospam with .gl

The current problem is that in depths of winter, two people
can't shower as hot water runs out (its a 36 * 18 copper
cylinder). It's a pumped shower. Will a fast recovery make
much of a difference. Max BTU of boiler is 40,000.

Make sure that you go for a larger cylinder than you already have. With only
a diddy boiler, the coil size will make little difference to your problem,
although it will be useful when the new boiler arrives.

If you have a good mains water supply, then consider fitting either an
unvented cylinder or a heat bank instead. These provide mains pressure
showers and rapid bath filling without the need for a noisy shower pump,
although it will cost more to do, being more of a Rolls Royce option.

Christian.

Christian McArdle wrote:
The current problem is that in depths of winter, two people
can't shower as hot water runs out (its a 36 * 18 copper
cylinder). It's a pumped shower. Will a fast recovery make
much of a difference. Max BTU of boiler is 40,000.

Make sure that you go for a larger cylinder than you already have.
With only
a diddy boiler, the coil size will make little difference to your
problem,
although it will be useful when the new boiler arrives.

If you have a good mains water supply, then consider fitting either
an
unvented cylinder or a heat bank instead. These provide mains
pressure
showers and rapid bath filling without the need for a noisy shower
pump,
although it will cost more to do, being more of a Rolls Royce option.

Thanks for the feedback.

If it is not going to make that much difference, I wonder if it is
worth doing. We only have one bathroom so I would have thought the
current 120l tank was sufficient - but as you say, the boiler just
really isn't up to the job!

We did think about unvented or a combi but our flow rate yesterday was
18 lpm, and that was Sunday afternoon. The plumber reckoned it would
drop to below 15 on a busy morning with everyone using water and that
was very much borderline. He did want to come back and check pressure
but suspected it was a bit low.

He said it would be best to upgrade the mains to get the full benefit
of an unvested cylinder or a combi.

KS

If it is not going to make that much difference, I wonder if it is
worth doing. We only have one bathroom so I would have thought the
current 120l tank was sufficient - but as you say, the boiler just
really isn't up to the job!

Well, 120L clearly isn't sufficient, because you are running out!

We did think about unvented or a combi but our flow rate yesterday was
18 lpm, and that was Sunday afternoon. The plumber reckoned it would
drop to below 15 on a busy morning with everyone using water and that
was very much borderline. He did want to come back and check pressure
but suspected it was a bit low.

Fair enough.

BTW, the water is running cold rather than actually stopping isn't it? If it
is running cold, it is your hot water cylinder running out of capacity. If
it stops running altogether, then your cold cistern is too small. This can
happen when using a 25 gallon tank with a poor mains water feed.

Christian.

"Christian McArdle" wrote in message
t...
If it is not going to make that much difference, I wonder if it is
worth doing. We only have one bathroom so I would have thought the
current 120l tank was sufficient - but as you say, the boiler just
really isn't up to the job!

Well, 120L clearly isn't sufficient, because you are running out!

We did think about unvented or a combi but our flow rate yesterday was
18 lpm, and that was Sunday afternoon. The plumber reckoned it would
drop to below 15 on a busy morning with everyone using water and that
was very much borderline. He did want to come back and check pressure
but suspected it was a bit low.

Fair enough.

BTW, the water is running cold rather than actually stopping isn't it? If
it
is running cold, it is your hot water cylinder running out of capacity. If
it stops running altogether, then your cold cistern is too small. This can
happen when using a 25 gallon tank with a poor mains water feed.

Christian.




Is the current cylinder plumbed properly, with the cold feed into the
bottom, and hot out of the top? I've seen one plumbed the wrong way round
with the result of very little hot water before it goes cold!
My cylinder is similar size to yours (36" x 18") and I can easily get 2
showers back-to-back from it, or a shower and (reasonably filled!) bath. Or
do you like loooong showers?

Alan.

In article .com,
KS wrote:
The current problem is that in depths of winter, two people can't
shower as hot water runs out (its a 36 * 18 copper cylinder). It's a
pumped shower. Will a fast recovery make much of a difference. Max BTU
of boiler is 40,000.

I doubt it - the boiler is simply too small to heat the water fast enough
regardless of the type of cylinder. And your cylinder is rather smaller
than ideal, too.

I've got a 100,000 BTU boiler older than yours with a fast recovery 160
litre cylinder, and feeding a shower gravity fed via 22mm pipe, it's
impossible to run it cold in practice. Of course if an entire football
team were using it one after another without the pause for undressing,
drying and dressing then yes. ;-)

--
*A clear conscience is usually the sign of a bad memory *

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