I recently helped a friend trace a central heating fault. The "wiring
centre" was a mess. A single gang surface pattress covered with
blanking plate and a mess of crimped connections inside made testing
and replacement of components difficult.

We plan to fit a conventional wiring centre at some time. System is
open vented Y-plan with an Ideal ICOS HE24 boiler fitted recently to
replace previous boiler. Unusually for a modern boiler there is no
pump overrun.

I was wondering if it is worth fitting a pipe thermostat to the flow
to give pump overrun when replacing the wiring centre. Pump live
would be fed from the thermostat common contact, thermostat normally
closed to switched live, and thermostat normally open to permanent
live.

Is there any point in bothering? Will it help boiler reliability?
There are no signs of boiler kettling or overheat lockout occurring
when call for heat is satisfied, but it seems a good thing to do if we
are fitting a new wiring centre.

Is the temperature setting of the pipe thermostat critical? I am
thinking:

1) if set too low, when call for hot water is satisfied the
circulating pump will keep running and wastefully extract stored
heat from the hot water cylinder, while on the other hand

2) if set too high, pump will never overrun when call for central
heating is satisfied, particularly with a modern condensing
boiler which is more efficient with a low temperature.

Is there any experience on the best setting for the pipe thermostat?

Regards,

MJA

"MJA" wrote in message
...
I recently helped a friend trace a central heating fault. The "wiring
centre" was a mess. A single gang surface pattress covered with
blanking plate and a mess of crimped connections inside made testing
and replacement of components difficult.

We plan to fit a conventional wiring centre at some time. System is
open vented Y-plan with an Ideal ICOS HE24 boiler fitted recently to
replace previous boiler. Unusually for a modern boiler there is no
pump overrun.

I was wondering if it is worth fitting a pipe thermostat to the flow
to give pump overrun when replacing the wiring centre. Pump live
would be fed from the thermostat common contact, thermostat normally
closed to switched live, and thermostat normally open to permanent
live.

Is there any point in bothering? Will it help boiler reliability?
There are no signs of boiler kettling or overheat lockout occurring
when call for heat is satisfied, but it seems a good thing to do if we
are fitting a new wiring centre.

Is the temperature setting of the pipe thermostat critical? I am
thinking:

1) if set too low, when call for hot water is satisfied the
circulating pump will keep running and wastefully extract stored
heat from the hot water cylinder, while on the other hand

2) if set too high, pump will never overrun when call for central
heating is satisfied, particularly with a modern condensing
boiler which is more efficient with a low temperature.

Is there any experience on the best setting for the pipe thermostat?

If the boiler doesn't have an overrun stat why fit one?
Its just more to go wrong later.

MJA wrote:
I recently helped a friend trace a central heating fault. The "wiring
centre" was a mess. A single gang surface pattress covered with
blanking plate and a mess of crimped connections inside made testing
and replacement of components difficult.

We plan to fit a conventional wiring centre at some time. System is
open vented Y-plan with an Ideal ICOS HE24 boiler fitted recently to
replace previous boiler. Unusually for a modern boiler there is no
pump overrun.

I was wondering if it is worth fitting a pipe thermostat to the flow
to give pump overrun when replacing the wiring centre. Pump live
would be fed from the thermostat common contact, thermostat normally
closed to switched live, and thermostat normally open to permanent
live.

Is there any point in bothering? Will it help boiler reliability?
There are no signs of boiler kettling or overheat lockout occurring
when call for heat is satisfied, but it seems a good thing to do if we
are fitting a new wiring centre.

Is the temperature setting of the pipe thermostat critical? I am
thinking:

1) if set too low, when call for hot water is satisfied the
circulating pump will keep running and wastefully extract stored
heat from the hot water cylinder, while on the other hand

2) if set too high, pump will never overrun when call for central
heating is satisfied, particularly with a modern condensing
boiler which is more efficient with a low temperature.

Is there any experience on the best setting for the pipe thermostat?


I would not bother if things are running OK. If you really did want a timer
overun then a seperate timer set for say 3 minutes would be my prefered
option eg
http://www.tlc-direct.co.uk/Products/BGDT20.html

--
Adam

On 20/04/2011 13:24, ARWadsworth wrote:


I was wondering if it is worth fitting a pipe thermostat to the flow
to give pump overrun when replacing the wiring centre. Pump live
would be fed from the thermostat common contact, thermostat normally
closed to switched live, and thermostat normally open to permanent
live.




I would not bother if things are running OK. If you really did want a timer
overun then a seperate timer set for say 3 minutes would be my prefered
option eg
http://www.tlc-direct.co.uk/Products/BGDT20.html


I'd second that.

But why worry about solving a problem you haven't got?!
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 20/04/2011 13:08, MJA wrote:
I recently helped a friend trace a central heating fault. The "wiring
centre" was a mess. A single gang surface pattress covered with
blanking plate and a mess of crimped connections inside made testing
and replacement of components difficult.

We plan to fit a conventional wiring centre at some time. System is
open vented Y-plan with an Ideal ICOS HE24 boiler fitted recently to
replace previous boiler. Unusually for a modern boiler there is no
pump overrun.

I was wondering if it is worth fitting a pipe thermostat to the flow
to give pump overrun when replacing the wiring centre. Pump live
would be fed from the thermostat common contact, thermostat normally
closed to switched live, and thermostat normally open to permanent
live.

Is there any point in bothering? Will it help boiler reliability?
There are no signs of boiler kettling or overheat lockout occurring
when call for heat is satisfied, but it seems a good thing to do if we
are fitting a new wiring centre.


I use a flow switch to turn on my boiler. That way the boiler can't fire
if there is no flow.

Perversely the switch failed, which had it happened early in out holiday
could have led to the house freezing. The switch also started to leak
though fortunately not enough to cause significant damage. The
replacement is much less likely to leak as it does not have a flexible
membrane!


--
Michael Chare

On 2011-04-20, ARWadsworth wrote:
MJA wrote:
I recently helped a friend trace a central heating fault. The "wiring
centre" was a mess. A single gang surface pattress covered with
blanking plate and a mess of crimped connections inside made testing
and replacement of components difficult.

We plan to fit a conventional wiring centre at some time. ....

I was wondering if it is worth fitting a pipe thermostat to the flow
to give pump overrun when replacing the wiring centre. ....

Is there any point in bothering? Will it help boiler reliability?

I would not bother if things are running OK. If you really did want a timer
overun then a seperate timer set for say 3 minutes would be my prefered
option eg
http://www.tlc-direct.co.uk/Products/BGDT20.html

That is interesting. I had only come across industrial DIN rail
mounting timers before, but using an extractor fan timer seems
more cost effective.

The consensus is just to fit a standard wiring centre and not worry
unless there are problems with the boiler kettling or going into
overheat lockout when the call for heat is satisfied.

If it were my own heating system, I think I might try experiments, but
as it is a friend's system I agree it should remain absolutely bog
standard and cause no surprises for anyone who repairs it later.

Thanks for all the comments.

MJA