Had a bit of a scare the other day when a boiler started making a
whining sound. Enough to go through the house and wake us in the
morning. I say 'a' boiler as we have two in tandem (large house, not my
choice as they were already here 2 x Ideal ICOS24's - yes, I already
know that Ideal are far from ideal). The advantage was that I could
just turn the one making the noise off.

I thought it might be the fan but did a Google and concluded that it
could be the heat exchanger and the system needs good flush so got some
cleaner to see if it would work. I haven't used it as when I turned
that boiler back on to have another listen, it didn't whine any more
(Sod's Law). So for the moment, the diagnosis is inconclusive but I
shall probably give it a run through with cleaner anyway very soon, now
I've bought it.

The master plan had been to install a thermal store (we need to get some
mains water up to the second floor and it's currently from a cylinder on
the first floor with a header immediately above it. If Mr Rumm is
reading this, it would be interesting to know how the unvented cylinder
project went!). Then, when it became necessary, I would swap the
boilers out for one large one.

In the face of a potential failure, the idea of having two boilers in
tandem seems like a good one, since we've been quite happy with just one
running for the past week (I know the weather has warmed up a lot and
that's probably why, but it proves the principle).

The biggest reason for the thermal store idea was that combi's are
generally rubbish for running a bath (I should duck here, knowing what
that will precipitate) but it occurs to me they're fine for a shower
(which is used more and likely to be the way to go on the top floor).
The other reason is to relocate the water cylinder (or store) to space
available on the ground floor and generate a bigger main bathroom.

So, a new master plan might be to: a) relocate the hot water cylinder
to the ground floor, keeping the header tank on the first floor
(probably a new tank involved here to ensure it can take the extra head)
b) as and when one of the boilers gives up the ghost, replace it with a
combi, piped to provide dhw to taps and showers.

Does this sound like a reasonable way forward? I could do without
making too much of a job of it as I have other major work planned for
the summer, assuming it comes this year.

In the current setup, the shower in the main bathroom has next to no
head so is fed through a pump from the cylinder for hot and its header
for cold. If I move the cylinder down a floor and keep the header where
it is, is this arrangement likely to still work (until the time comes to
put a combi in)? My conception of the pressures says it should be no
different but perhaps someone knows otherwise.

Sorry that's a bit long but trying to give the necessary info.

In message , GMM
writes
Had a bit of a scare the other day when a boiler started making a
whining sound. Enough to go through the house and wake us in the
morning. I say 'a' boiler as we have two in tandem (large house, not
my choice as they were already here 2 x Ideal ICOS24's - yes, I already
know that Ideal are far from ideal). The advantage was that I could
just turn the one making the noise off.



It could be as simple as a split washer acting like a reed. You need to
home in on the noise


--
geoff

On 17/04/2013 21:47, geoff wrote:
In message , GMM
writes
Had a bit of a scare the other day when a boiler started making a
whining sound. Enough to go through the house and wake us in the
morning. I say 'a' boiler as we have two in tandem (large house, not
my choice as they were already here 2 x Ideal ICOS24's - yes, I
already know that Ideal are far from ideal). The advantage was that I
could just turn the one making the noise off.



It could be as simple as a split washer acting like a reed. You need to
home in on the noise


Indeed. Though, like any intermittent fault, tricky to do when it isn't
happening....

On Wednesday 17 April 2013 20:25 wrote in uk.d-i-y:

Had a bit of a scare the other day when a boiler started making a
whining sound. Enough to go through the house and wake us in the
morning. I say 'a' boiler as we have two in tandem (large house, not my
choice as they were already here 2 x Ideal ICOS24's - yes, I already
know that Ideal are far from ideal). The advantage was that I could
just turn the one making the noise off.

I thought it might be the fan but did a Google and concluded that it
could be the heat exchanger and the system needs good flush so got some
cleaner to see if it would work. I haven't used it as when I turned
that boiler back on to have another listen, it didn't whine any more
(Sod's Law). So for the moment, the diagnosis is inconclusive but I
shall probably give it a run through with cleaner anyway very soon, now
I've bought it.

The master plan had been to install a thermal store (we need to get some
mains water up to the second floor and it's currently from a cylinder on
the first floor with a header immediately above it. If Mr Rumm is
reading this, it would be interesting to know how the unvented cylinder
project went!). Then, when it became necessary, I would swap the
boilers out for one large one.

In the face of a potential failure, the idea of having two boilers in
tandem seems like a good one, since we've been quite happy with just one
running for the past week (I know the weather has warmed up a lot and
that's probably why, but it proves the principle).

The biggest reason for the thermal store idea was that combi's are
generally rubbish for running a bath (I should duck here, knowing what
that will precipitate) but it occurs to me they're fine for a shower
(which is used more and likely to be the way to go on the top floor).
The other reason is to relocate the water cylinder (or store) to space
available on the ground floor and generate a bigger main bathroom.

So, a new master plan might be to: a) relocate the hot water cylinder
to the ground floor, keeping the header tank on the first floor
(probably a new tank involved here to ensure it can take the extra head)
b) as and when one of the boilers gives up the ghost, replace it with a
combi, piped to provide dhw to taps and showers.

Does this sound like a reasonable way forward? I could do without
making too much of a job of it as I have other major work planned for
the summer, assuming it comes this year.

In the current setup, the shower in the main bathroom has next to no
head so is fed through a pump from the cylinder for hot and its header
for cold. If I move the cylinder down a floor and keep the header where
it is, is this arrangement likely to still work (until the time comes to
put a combi in)? My conception of the pressures says it should be no
different but perhaps someone knows otherwise.

Sorry that's a bit long but trying to give the necessary info.

Why not arrange for the thermal store to have a couple of immersion bosses -
both low down. Then you have the option to charge it via electricity which
could make sense with an Economy 7 tarrif - and gives you an elegant backup
if the one boiler goes pop.

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

Reading this on the web? See:
http://wiki.diyfaq.org.uk/index.php?title=Usenet

On 17/04/2013 20:25, GMM wrote:

The master plan had been to install a thermal store (we need to get some
mains water up to the second floor and it's currently from a cylinder on
the first floor with a header immediately above it. If Mr Rumm is
reading this,

fx: waves

it would be interesting to know how the unvented cylinder
project went!).

Well, so far so good - it meets expectations in pretty much every way.

There were two goals for the exercise... one was to sort the dismal hot
water performance, and the other to attempt to improve the efficiency of
the heating.

A summary of the problems with the old setup:

Hot water was a conventional gravity system. However given the house is
a chalet style conversion it meant the header tank was on the first
floor in a cupboard, about 5' off the floor level. That meant pressure
to taps upstairs was as little as 2' of head in some cases. You also
could not have an unpumped shower upstairs since the head would be above
the tank level. In addition, reheat times were not fast given it was a
"normal" cylinder heated indirectly from a fully pumped S Plan
arrangement. Mains cold water is available at 5 bar and fire hose flow
rates.

The second issue was heating... that was a problem in a few ways. Old
cast iron lump boiler, no pump overrun, single rad zone in a property
where the upstairs is a smaller and much better insulated area/volume
than the downstairs. Also an exposed location with high variability in
the rate of heat loss and hence heating requirements. Finally some areas
of the downstairs never really achieved target temperature in spite of
balancing the rads.

Options to fix:

To fix the heating system issues, I wanted to go S Plan+ with two
heating zones, each with its own prog stat. Plus a DHW zone. Rad sizes
needed adjusting downstairs to increase the output in some areas, and
also to add one to the utility room that would lose the contribution of
"waste" heat from the boiler itself. To gain maximum efficiency, year
round comfort, and deal with the variability of the heating load, I
decided that weather compensation[1] would be a sensible addition.

DHW really then came down to either a heat bank type of arrangement, or
unvented cylinder. Possibly with a combi in the mix to feed the
utility/kitchen that are on a longish dead leg of pipe.

Decision making process:

I rejected the traditional thermal store to do "everything" arrangement
on the grounds that firstly it would need to be *massive* to have a hope
of running 21 rads and coping with DHW demands of multiple baths /
showers, and secondly I was not convinced that there would be much
efficiency gain (if any) over a modern modulating boiler with weather
compensation. So that left a heat bank for DHW only, or unvented. The
commercial DHW heat banks like the Pandora looked ok in theory, but the
quote I got was too much (pushing 2K for a 250L IIRC). Pricing the DIY
heat bank, showed that it was in much the same ballpark as an unvented
cylinder by the time you have accumulated all the bits. So in the end I
opted for the unvented on the grounds that its easy to buy the whole
system in one box ready to go, and it will also integrate with the
boiler controls easily.

The boiler needed to be a "split temperature" capable device to allow
for reheat on the cylinder, while still being able to run the rads at
the weather compensated temperature demand (can be 40 degrees or less
when its not too cold outside). That limited the choice a bit, and I
also could not find a combi that would do that, so it meant using a
system boiler.

Solution implemented:

Replace three rads downstairs with larger ones, relocate two of the
liberated ones to replace smaller ones, and install the last "spare" one
in the utility room. Fit TRVs on 9 rads that did not have them. Split
the heating into two zones. Installed a Vaillant Eco+ 624 boiler,
Unistor 210L cylinder, VRC470 weather compensator (also acts as main
prog stat), their VR61/2 wiring centre (interfaces the 240V zone valves
to the ebus system used by the other bits), and a VR81/2 Aux control to
act as prog stat for upstairs.

Result:

Works nicely - downstairs is now a nice even temperature all round.
Upstairs does not overheat. System is quiet and effective. Will need to
see a years worth of bills to assess the impact on gas use though!

Hot water delivery is impressive everywhere (even the dead leg to the
kitchen is less of an issue due to the rate of delivery). There are no
obvious interactions caused by simultaneous demands either which is
nice. I also have a large cupboard in our en-suite that will make a nice
shower when I get the required shape of tuit. If I were doing it again,
I might have gone for the 300L cylinder. The cylinder will swallow heat
from the boiler at 22kW, so reheat is pretty close to optimal. The
boiler also condenses during reheat, and adjusts its flow temperature as
it goes to do as much of it at high efficiency as possible.

Then, when it became necessary, I would swap the
boilers out for one large one.

In the face of a potential failure, the idea of having two boilers in
tandem seems like a good one, since we've been quite happy with just one
running for the past week (I know the weather has warmed up a lot and
that's probably why, but it proves the principle).

The biggest reason for the thermal store idea was that combi's are
generally rubbish for running a bath (I should duck here, knowing what
that will precipitate) but it occurs to me they're fine for a shower

Remember you can also heat a cylinder (or store etc) from a combi as
well. (although see my comments on conflicting requirements above)

(which is used more and likely to be the way to go on the top floor).
The other reason is to relocate the water cylinder (or store) to space
available on the ground floor and generate a bigger main bathroom.

So, a new master plan might be to: a) relocate the hot water cylinder
to the ground floor, keeping the header tank on the first floor

Is there a loft available?

If not, then I would look at a solution that can use mains DHW if your
mains is good enough.

(probably a new tank involved here to ensure it can take the extra head)
b) as and when one of the boilers gives up the ghost, replace it with a
combi, piped to provide dhw to taps and showers.

Does this sound like a reasonable way forward? I could do without
making too much of a job of it as I have other major work planned for
the summer, assuming it comes this year.

Sounds doable certainly.

In the current setup, the shower in the main bathroom has next to no
head so is fed through a pump from the cylinder for hot and its header
for cold. If I move the cylinder down a floor and keep the header where
it is, is this arrangement likely to still work (until the time comes to
put a combi in)? My conception of the pressures says it should be no
different but perhaps someone knows otherwise.

It should work just the same... you may want to move the pump to be
closer to the cylinder though. The extra relative head at the cylinder
should also reduce the possibility of cavitation or air ingress.

Sorry that's a bit long but trying to give the necessary info.

Sorry for the long answer ;-)

[1] My ideal weather compensator ought to include an anemometer as well
here - since the cooling effect of the wind is noticeable.


--
Cheers,

John.

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

On 18/04/2013 10:24, Tim Watts wrote:
On Wednesday 17 April 2013 20:25 wrote in uk.d-i-y:

Had a bit of a scare the other day when a boiler started making a
whining sound. Enough to go through the house and wake us in the
morning. I say 'a' boiler as we have two in tandem (large house, not my
choice as they were already here 2 x Ideal ICOS24's - yes, I already
know that Ideal are far from ideal). The advantage was that I could
just turn the one making the noise off.

I thought it might be the fan but did a Google and concluded that it
could be the heat exchanger and the system needs good flush so got some
cleaner to see if it would work. I haven't used it as when I turned
that boiler back on to have another listen, it didn't whine any more
(Sod's Law). So for the moment, the diagnosis is inconclusive but I
shall probably give it a run through with cleaner anyway very soon, now
I've bought it.

The master plan had been to install a thermal store (we need to get some
mains water up to the second floor and it's currently from a cylinder on
the first floor with a header immediately above it. If Mr Rumm is
reading this, it would be interesting to know how the unvented cylinder
project went!). Then, when it became necessary, I would swap the
boilers out for one large one.

In the face of a potential failure, the idea of having two boilers in
tandem seems like a good one, since we've been quite happy with just one
running for the past week (I know the weather has warmed up a lot and
that's probably why, but it proves the principle).

The biggest reason for the thermal store idea was that combi's are
generally rubbish for running a bath (I should duck here, knowing what
that will precipitate) but it occurs to me they're fine for a shower
(which is used more and likely to be the way to go on the top floor).
The other reason is to relocate the water cylinder (or store) to space
available on the ground floor and generate a bigger main bathroom.

So, a new master plan might be to: a) relocate the hot water cylinder
to the ground floor, keeping the header tank on the first floor
(probably a new tank involved here to ensure it can take the extra head)
b) as and when one of the boilers gives up the ghost, replace it with a
combi, piped to provide dhw to taps and showers.

Does this sound like a reasonable way forward? I could do without
making too much of a job of it as I have other major work planned for
the summer, assuming it comes this year.

In the current setup, the shower in the main bathroom has next to no
head so is fed through a pump from the cylinder for hot and its header
for cold. If I move the cylinder down a floor and keep the header where
it is, is this arrangement likely to still work (until the time comes to
put a combi in)? My conception of the pressures says it should be no
different but perhaps someone knows otherwise.

Sorry that's a bit long but trying to give the necessary info.

Why not arrange for the thermal store to have a couple of immersion bosses -
both low down. Then you have the option to charge it via electricity which
could make sense with an Economy 7 tarrif - and gives you an elegant backup
if the one boiler goes pop.

I think I would certainly have one, even without the Economy 7, as a
backup, even though that would give 3 different ways of making dhw (!)

(all snipped out as we're getting pretty long!)

Many thanks for such an extensive description, John.

It sounds like a very similar situation to here, except we have the
added issue of an extra floor. The head in our bathroom is about
similar to your original setup, ie nowhere near enough, and then there's
another floor above that where I would like (eventually) to fit an
en-suite. Unfortunately, there's no loft above the top floor, so no
chance of getting any sort of head up there (ohh err vicar).

Also, we have very good mains pressure and flow. Next door measured 4
bar on the top floor and I had a new feed in from the main when we
moved in just over a year ago.

Similarly, I have never considered using a thermal store for all of the
heating as well as hot water: We have 20 rads and there will be UFH in
the conservatory replacement/extension, but I was thinking it might be
useful for feeding the UFH.

I think we may wind up with an unvented cylinder though, for the
pragmatic reason of cost over outcome, much the same as you did. I
don't have any sophisticated control on this system as yet (have been
considering whether that, and zoning, might help the massive gas bills),
just TRVs all round, but we're nowhere near as exposed and get some good
sun on the back of the house.

And the underfloor insulation made a huge difference, together with some
draughtproofing. I think it'll be a long time (and a lot of celotex)
before we ever see a nice even temperature around this place though!

I do rather like the idea of a tsunami every time a hot tap is opened.
If nothing else, it would make buying taps a lot easier when we refit
the bathroom and kitchen (!).

One nagging question I did have in contemplating mains pressure hot
water is whether I'll have to re-plumb the whole place to avoid leaks in
awkward spots: Judging by the standard of most visible plumbing, I've a
feeling it could be a real risk and I would feel a lot better if it was
all in continuous runs of plastic where it's not accessible. I don't
think that's as bad a job as it sounds since quite a bit of it needs
changing anyway to move things around and to get rid of some runs of
iron pipe. There might even be some lead at one point, if I'm guessing
correctly.

Apart from the efficiency, is there any other issue with the 210L
cylinder? It sounds like that should be enough to cope with most
demands unless you have a lot of people in the house.

At present, I'm relieved that the boiler doesn't seem to be about to
give up immediately and I have some more time to give this some thought,
as it's a pretty serious investment, whatever the details.

Cheers!

On 18/04/2013 23:53, GMM wrote:
(all snipped out as we're getting pretty long!)

Many thanks for such an extensive description, John.

It sounds like a very similar situation to here, except we have the
added issue of an extra floor. The head in our bathroom is about
similar to your original setup, ie nowhere near enough, and then there's
another floor above that where I would like (eventually) to fit an
en-suite. Unfortunately, there's no loft above the top floor, so no
chance of getting any sort of head up there (ohh err vicar).

Yup, I had a similar situation on the previous place when I did the loft
conversion.

While you can get negative head shower pumps etc...

Also, we have very good mains pressure and flow. Next door measured 4
bar on the top floor and I had a new feed in from the main when we moved
in just over a year ago.

....in these circumstances it seems sensible to go for a mains fed solution.

Similarly, I have never considered using a thermal store for all of the
heating as well as hot water: We have 20 rads and there will be UFH in
the conservatory replacement/extension, but I was thinking it might be
useful for feeding the UFH.

Indeed it could. Having said that, the box of tricks that I used to
interface my modern boiler to my "traditional" 2 port valves, also had
the capability of controlling blending valves for UFH zones. It could
support a couple of "controlled" (i.e. blended) zones if required.

I think we may wind up with an unvented cylinder though, for the
pragmatic reason of cost over outcome, much the same as you did. I
don't have any sophisticated control on this system as yet (have been
considering whether that, and zoning, might help the massive gas bills),
just TRVs all round, but we're nowhere near as exposed and get some good
sun on the back of the house.

The cylinder I used seemed pretty flexible in its installation and
integration capabilities. It came with a new zone valve, and the
temperature sensor that could feed the control system[1] as well as the
normal stats and interlocks etc. So you can hook them up to pretty much
anything.

[1] One of the irritations with the Vaillant documentation being that
the boiler manual gives details of system wiring using one particular
model of wiring centre. It gives the (quite logical) impression that the
supplied temperature sensor in the cylinder is wired back to the wiring
centre, and it communicates the required information to the boiler via
ebus. It was a tad annoying to be at the hooking things up stage to find
that the wiring centre had different ideas, and suddenly find you need
yet another wire directly back to the boiler from the sensor. (and when
it gets there, there is nowhere to terminate it, without first chopping
off an internal connector that would have been used on the combi varient
for its DHW water temp sensor, and chock block wiring it to that!)

And the underfloor insulation made a huge difference, together with some
draughtproofing. I think it'll be a long time (and a lot of celotex)
before we ever see a nice even temperature around this place though!

Indeed, and to be fair I was surprised that I managed it here... this
may have been by brute force (one or two of the new rads I put in a
fairly hefty). Controlling the under floor ventilation levels have also
helped.

Exterior wall insulation will be the next "big" job.

I do rather like the idea of a tsunami every time a hot tap is opened.
If nothing else, it would make buying taps a lot easier when we refit
the bathroom and kitchen (!).

Yup.

One nagging question I did have in contemplating mains pressure hot
water is whether I'll have to re-plumb the whole place to avoid leaks in
awkward spots: Judging by the standard of most visible plumbing, I've a
feeling it could be a real risk and I would feel a lot better if it was
all in continuous runs of plastic where it's not accessible. I don't
think that's as bad a job as it sounds since quite a bit of it needs
changing anyway to move things around and to get rid of some runs of
iron pipe. There might even be some lead at one point, if I'm guessing
correctly.

Pipes generally are not usually fussed by a bit of extra pressure - it
tends to be more of an issue when converting old vented heating systems
to sealed systems where lockshields may weep or knackered rads pinhole etc.

Apart from the efficiency, is there any other issue with the 210L
cylinder? It sounds like that should be enough to cope with most
demands unless you have a lot of people in the house.

Have a look at:

http://wiki.diyfaq.org.uk/index.php?...water_cylinder

for chapter and verse...

But in general 210 is not a bad size, although a couple of showers in
sequence can use it all unless you have some reheating.

If you want to heat just the once (say using overnight cheap lekky), or
don't want the boiler diverted from the heating at anytime, you may need
more. If however you are content to let the boiler heat it when required
(which it needs to do exclusively on my system), then you can get away
with less since it will degrade into a combi style system if required,
with the boiler reheating the water on the fly as its being used.

I have set mine up to do a full heat in the morning before the heating
is due to come on, then at a couple of other times during the day. If I
know I am about to make massive demands on it, then I enable cylinder
boost on the controller.

At present, I'm relieved that the boiler doesn't seem to be about to
give up immediately and I have some more time to give this some thought,
as it's a pretty serious investment, whatever the details.

Yup, just the cylinder on its own is going to be pushing £800 to a
grand by the time its in, if you DIY.

--
Cheers,

John.

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

On 19/04/2013 11:12, John Rumm wrote:
On 18/04/2013 23:53, GMM wrote:
(all snipped out as we're getting pretty long!)

Many thanks for such an extensive description, John.

It sounds like a very similar situation to here, except we have the
added issue of an extra floor. The head in our bathroom is about
similar to your original setup, ie nowhere near enough, and then there's
another floor above that where I would like (eventually) to fit an
en-suite. Unfortunately, there's no loft above the top floor, so no
chance of getting any sort of head up there (ohh err vicar).

Yup, I had a similar situation on the previous place when I did the loft
conversion.

While you can get negative head shower pumps etc...

Also, we have very good mains pressure and flow. Next door measured 4
bar on the top floor and I had a new feed in from the main when we moved
in just over a year ago.

...in these circumstances it seems sensible to go for a mains fed solution.

Similarly, I have never considered using a thermal store for all of the
heating as well as hot water: We have 20 rads and there will be UFH in
the conservatory replacement/extension, but I was thinking it might be
useful for feeding the UFH.

Indeed it could. Having said that, the box of tricks that I used to
interface my modern boiler to my "traditional" 2 port valves, also had
the capability of controlling blending valves for UFH zones. It could
support a couple of "controlled" (i.e. blended) zones if required.

True -I've no doubt there are a number of solutions given a little
thought (which I haven't quite fully put into it all yet!)


I think we may wind up with an unvented cylinder though, for the
pragmatic reason of cost over outcome, much the same as you did. I
don't have any sophisticated control on this system as yet (have been
considering whether that, and zoning, might help the massive gas bills),
just TRVs all round, but we're nowhere near as exposed and get some good
sun on the back of the house.

The cylinder I used seemed pretty flexible in its installation and
integration capabilities. It came with a new zone valve, and the
temperature sensor that could feed the control system[1] as well as the
normal stats and interlocks etc. So you can hook them up to pretty much
anything.

[1] One of the irritations with the Vaillant documentation being that
the boiler manual gives details of system wiring using one particular
model of wiring centre. It gives the (quite logical) impression that the
supplied temperature sensor in the cylinder is wired back to the wiring
centre, and it communicates the required information to the boiler via
ebus. It was a tad annoying to be at the hooking things up stage to find
that the wiring centre had different ideas, and suddenly find you need
yet another wire directly back to the boiler from the sensor. (and when
it gets there, there is nowhere to terminate it, without first chopping
off an internal connector that would have been used on the combi varient
for its DHW water temp sensor, and chock block wiring it to that!)

And the underfloor insulation made a huge difference, together with some
draughtproofing. I think it'll be a long time (and a lot of celotex)
before we ever see a nice even temperature around this place though!

Indeed, and to be fair I was surprised that I managed it here... this
may have been by brute force (one or two of the new rads I put in a
fairly hefty). Controlling the under floor ventilation levels have also
helped.

I'm guessing you found a good way to baffle your underfloor vents then.
I recall a thread on that a while ago. Judging byt eh change in the
weather it might be time to open them up a little soon (though it could
be snowing next week for all we know!)


Exterior wall insulation will be the next "big" job.

The more I think of it, the more exterior insulation makes sense though
I suspect it's not an option I can implement much given the nature of
the house (red brick semi).


I do rather like the idea of a tsunami every time a hot tap is opened.
If nothing else, it would make buying taps a lot easier when we refit
the bathroom and kitchen (!).

Yup.

One nagging question I did have in contemplating mains pressure hot
water is whether I'll have to re-plumb the whole place to avoid leaks in
awkward spots: Judging by the standard of most visible plumbing, I've a
feeling it could be a real risk and I would feel a lot better if it was
all in continuous runs of plastic where it's not accessible. I don't
think that's as bad a job as it sounds since quite a bit of it needs
changing anyway to move things around and to get rid of some runs of
iron pipe. There might even be some lead at one point, if I'm guessing
correctly.

Pipes generally are not usually fussed by a bit of extra pressure - it
tends to be more of an issue when converting old vented heating systems
to sealed systems where lockshields may weep or knackered rads pinhole etc.

Well, that's another issue for me - I'd like to convert my open system
to a pressurised one but sort of dread opening the can of worms.
Although my rads look generally OK, clearly those on the upper floors
have never experienced significant pressure so some joints could be
delicate without knowing it. Of course, rads can look OK and still be
about to burst....
I suppose there must be a way to test whether the system can take a
decent pressure, though to do it, I suspect it's pretty much necessary
to swap over and by then the deed is done.


Apart from the efficiency, is there any other issue with the 210L
cylinder? It sounds like that should be enough to cope with most
demands unless you have a lot of people in the house.

Have a look at:

http://wiki.diyfaq.org.uk/index.php?...water_cylinder

for chapter and verse...

But in general 210 is not a bad size, although a couple of showers in
sequence can use it all unless you have some reheating.

If you want to heat just the once (say using overnight cheap lekky), or
don't want the boiler diverted from the heating at anytime, you may need
more. If however you are content to let the boiler heat it when required
(which it needs to do exclusively on my system), then you can get away
with less since it will degrade into a combi style system if required,
with the boiler reheating the water on the fly as its being used.

Well, dspite having a pretty alrge house, there are only 2 of us here
most of the time, so I would guess 210L would do the job. There seems
little purpose in skimping given the relatively low costs involved
compared with smaller ones.

Given the location (sout-facing at the back), I'm tempted to have a go
at a DIY solar DHW solution, so would get a solar cylinder then bodge on
whatever I rig up to that. Again, there seems little to lose and if it
doesn't work, msot of the lost cost is in my time.


I have set mine up to do a full heat in the morning before the heating
is due to come on, then at a couple of other times during the day. If I
know I am about to make massive demands on it, then I enable cylinder
boost on the controller.

At present, I'm relieved that the boiler doesn't seem to be about to
give up immediately and I have some more time to give this some thought,
as it's a pretty serious investment, whatever the details.

Yup, just the cylinder on its own is going to be pushing £800 to a
grand by the time its in, if you DIY.

Indeed. A grand or so was what I had in mind. Then the boiler started
making what could be expensive noises and with that it could more than
double. On teh other hand, the summer is the time to deal with these
things, when you can lose the heating for a few days if necessary.

Once I have sorted the water, I'll be able to get started on the
bathroom..but that's another story.....

On 25/04/2013 14:28, GMM wrote:
On 19/04/2013 11:12, John Rumm wrote:

Similarly, I have never considered using a thermal store for all of the
heating as well as hot water: We have 20 rads and there will be UFH in
the conservatory replacement/extension, but I was thinking it might be
useful for feeding the UFH.

Indeed it could. Having said that, the box of tricks that I used to
interface my modern boiler to my "traditional" 2 port valves, also had
the capability of controlling blending valves for UFH zones. It could
support a couple of "controlled" (i.e. blended) zones if required.

True -I've no doubt there are a number of solutions given a little
thought (which I haven't quite fully put into it all yet!)

Yup, I found working backwards from the desired result + analysing what
bits actually mattered helped.

So for example some folks cite the inclusion of unvented cylinders in
the G3 regs as being more onerous, however since *all* cylinders are now
included in G3 it matters less. Same goes for servicing - the
requirements are not that onerous.

And the underfloor insulation made a huge difference, together with some
draughtproofing. I think it'll be a long time (and a lot of celotex)
before we ever see a nice even temperature around this place though!

Indeed, and to be fair I was surprised that I managed it here... this
may have been by brute force (one or two of the new rads I put in a
fairly hefty). Controlling the under floor ventilation levels have also
helped.

I'm guessing you found a good way to baffle your underfloor vents then.
I recall a thread on that a while ago. Judging byt eh change in the
weather it might be time to open them up a little soon (though it could
be snowing next week for all we know!)

I got some ali hit'n'miss vents that I mounted over the air bricks, and
then throttled them down to more miss than hit on the windy sides...

I will open them up some soon.

Exterior wall insulation will be the next "big" job.

The more I think of it, the more exterior insulation makes sense though
I suspect it's not an option I can implement much given the nature of
the house (red brick semi).

Yup, much harder to preserve attractive brickwork... there are some
systems that allow for brick slip panels to be fitted - but even then
you would need to do something at the join to the semi to hide the
thickness change (unless you can talk the neighbours into doing it at
the same time)

I do rather like the idea of a tsunami every time a hot tap is opened.
If nothing else, it would make buying taps a lot easier when we refit
the bathroom and kitchen (!).

Yup.

One nagging question I did have in contemplating mains pressure hot
water is whether I'll have to re-plumb the whole place to avoid leaks in
awkward spots: Judging by the standard of most visible plumbing, I've a
feeling it could be a real risk and I would feel a lot better if it was
all in continuous runs of plastic where it's not accessible. I don't
think that's as bad a job as it sounds since quite a bit of it needs
changing anyway to move things around and to get rid of some runs of
iron pipe. There might even be some lead at one point, if I'm guessing
correctly.

Pipes generally are not usually fussed by a bit of extra pressure - it
tends to be more of an issue when converting old vented heating systems
to sealed systems where lockshields may weep or knackered rads pinhole
etc.

Well, that's another issue for me - I'd like to convert my open system
to a pressurised one but sort of dread opening the can of worms.

Well I have done it a couple of times now, and so far not had a problem.

Although my rads look generally OK, clearly those on the upper floors
have never experienced significant pressure so some joints could be
delicate without knowing it. Of course, rads can look OK and still be
about to burst....

I think they need to be pretty close to failing anyway for it to matter.

I suppose there must be a way to test whether the system can take a
decent pressure, though to do it, I suspect it's pretty much necessary
to swap over and by then the deed is done.

I suppose you could add a filling loop and pressure gauge, and
temporarily block the vent pipes to test.

Apart from the efficiency, is there any other issue with the 210L
cylinder? It sounds like that should be enough to cope with most
demands unless you have a lot of people in the house.

Have a look at:

http://wiki.diyfaq.org.uk/index.php?...water_cylinder

for chapter and verse...

But in general 210 is not a bad size, although a couple of showers in
sequence can use it all unless you have some reheating.

If you want to heat just the once (say using overnight cheap lekky), or
don't want the boiler diverted from the heating at anytime, you may need
more. If however you are content to let the boiler heat it when required
(which it needs to do exclusively on my system), then you can get away
with less since it will degrade into a combi style system if required,
with the boiler reheating the water on the fly as its being used.

Well, dspite having a pretty alrge house, there are only 2 of us here
most of the time, so I would guess 210L would do the job. There seems
little purpose in skimping given the relatively low costs involved
compared with smaller ones.

Yup the price delta is not huge from the smallest ones.

Given the location (sout-facing at the back), I'm tempted to have a go
at a DIY solar DHW solution, so would get a solar cylinder then bodge on
whatever I rig up to that. Again, there seems little to lose and if it
doesn't work, msot of the lost cost is in my time.

The solar coil will add a little to the price of the cylinder, but as
you say not much in the grand scheme, and if you can contrive some way
to use it, it would probably pay for the extra cost fairly quickly.

I have set mine up to do a full heat in the morning before the heating
is due to come on, then at a couple of other times during the day. If I
know I am about to make massive demands on it, then I enable cylinder
boost on the controller.

At present, I'm relieved that the boiler doesn't seem to be about to
give up immediately and I have some more time to give this some thought,
as it's a pretty serious investment, whatever the details.

Yup, just the cylinder on its own is going to be pushing £800 to a
grand by the time its in, if you DIY.

Indeed. A grand or so was what I had in mind. Then the boiler started
making what could be expensive noises and with that it could more than
double. On teh other hand, the summer is the time to deal with these
things, when you can lose the heating for a few days if necessary.

Yup, I originally expect about 2k, but by the time you add on three new
rads, several electronic boxes of tricks, blending valve, new TRVs etc,
it soon creeps up. In the end it was just under 3k all in.

Glad I got mine done in the remnants of summer last year. Its certainly
been more pleasant to live with... might even save some money as well
with luck!

Once I have sorted the water, I'll be able to get started on the
bathroom..but that's another story.....

;-)

Yes I have a nice shower sized space that used to hold cisterns of
various types, just waiting for some attention.

--
Cheers,

John.

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