Assuming a heat-only sysem with boiler, pump and
radiators (emitters!!), apart from a thermostat
what controls would be needed other than a timer ?.

I assume that a programmable stat would do the timing
and temp control, so no need for a wiring centre.

Would the boiler provide the power for the pump or
is a relay required ?.

On 23/11/2019 14:18, Andrew wrote:
Assuming a heat-only sysem with boiler, pump and
radiators (emitters!!), apart from a thermostat
what controls would be needed other than a timer ?.

I assume that a programmable stat would do the timing
and temp control, so no need for a wiring centre.

Would the boiler provide the power for the pump or
is a relay required ?.

Pump operated from the boiler will allow for timed overrun. Pump in
parallel with the boiler power connections from a 'stat switching mains
will just not have an overrun facility. System boilers have the pump and
an expansion vessel built in.

SteveW

Different models of boiler have a number of options. There are plenty of wiring diagrams on t'interweb for the possibilities or you can look at the installation instructions for whichever boiler you decide on.

It might be better to go to the DIYWiki first and read up about what systems are available and which you think suits you then come back with specific questions, it is to big topic to reply in a return post.

Richard

Tricky Dicky wrote:

It might be better to go to the DIYWiki first and read up about what systems are available

Also what controls Part L might require (if it's a new or replacement
boiler) these vary depending if it's a combi or not (the O/P did say
system boiler) and size of dwelling.

On 23/11/2019 14:18, Andrew wrote:
Assuming a heat-only sysem with boiler, pump and
radiators (emitters!!), apart from a thermostat
what controls would be needed other than a timer ?.

I assume that a programmable stat would do the timing
and temp control, so no need for a wiring centre.

Would the boiler provide the power for the pump or
is a relay required ?.

It may depend on the boiler but mine provides the power to the pump
which includes the pump overrun to stop the pump switching off instantly
off the heating demand has been satisfied. The heat exchanger will still
be hot when the burners switch off and if the pump is stopped
immediately at this time the latent heat in the heat exchanger will be
transferred to the non flowing water - hence the need to keep it being
pumped for a while.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Sat, 23 Nov 2019 16:25:04 +0000, Steve Walker wrote:

Assuming a heat-only sysem with boiler, pump and radiators
(emitters!!), apart from a thermostat what controls would be
needed
other than a timer ?.

Thermostatic valves on radiators if you want to heat some rooms more
(or less) than others.

Pump in parallel with the boiler power connections from a 'stat
switching mains will just not have an overrun facility.

A change over pipe stat will sort that though

/ Room Stat
/
+V ----+----o o----+---------- Boiler
| |
| |
| o cold
| \
| \
| o------- Pump
|
|
+-------------o hot

--
Cheers
Dave.