Advice on stat - programmer

[liam2308]

have installed a cm927 honeywell room stat/programmer. I would like to use this as my programmer. At present I have it wired so that when stat calls for heat boiler comes on as well as the pump. Once the stat is satified boiler and pump go off. Is it possible to wire so that the pump continues to pump the hot water from boiler. Or are heating systems designed so that pump and boiler are on together and off together. This is a fully pumped system. But it makes sense for me that the pump continues to move water even with the boiler off. I cannot see how to wire this but I have noticed on cm927 receiver extra connections and was wondering if these could be used with pump. At present both pump and boiler together are wired to the switched live on the receiver.

 

[gas4you]

The receiver should be wired into the wiring center for the heating system if it is fully pumped.

Unless your boiler has a built in pump over run then the pump will not continue on its own.

 

[D_Hailsham]

Is it possible to wire so that the pump continues to pump the hot water from boiler. Or are heating systems designed so that pump and boiler are on together and off together. This is a fully pumped system. But it makes sense for me that the pump continues to move water even with the boiler off.

Why do you want the water to continue circulating? The radiators will still be giving off heat, even if the water is stationary. In any case it's not so simple as just having the pump run continuously.

"Constant circulation" is quite common on the continent and in USA. I came across it when trawling an American heating web site.

There is a bit about it in This Article. It starts about halfway down. Search for "constant circulation".

 

[liam2308]

Is it possible to wire so that the pump continues to pump the hot water from boiler. Or are heating systems designed so that pump and boiler are on together and off together. This is a fully pumped system. But it makes sense for me that the pump continues to move water even with the boiler off.

Why do you want the water to continue circulating? The radiators will still be giving off heat, even if the water is stationary. In any case it's not so simple as just having the pump run continuously.

"Constant circulation" is quite common on the continent and in USA. I came across it when trawling an American heating web site.

There is a bit about it in This Article. It starts about halfway down. Search for "constant circulation".

MANY THANKS previously I had a horstmann 425 diadem. very simple - timer sends live to pump and boiler - pump is on all the time for the timed period and boiler is controlled by its stat and cyles normally. But I have no Room stat to control temperature I purchased cm927 to control temperature. But it seems to me that the old system is more effctive continously moving the hot water - point taken that radiators are warm and will continue to give of heat. Boiler I have does not have over run.

 

[twgas]

Baxi (I think) do a pump timer which can be wired to make the pump run after the stats shut down, but you shouldn't generally need one.