Boiler on demand/stop cycling

[Kes]

This might not be answerable except in general terms.

I have a Danesmoor 26/32 CF oil boiler with integral programmer, 28mm gravity f/r to large vented h/w cylinder, room stat, pump to rads and trvs. All standard 1970's stuff. The boiler is used for heating only (through the programmer), but of course when the heating is on the hot water is heated as well.

What I want to do is to stop the boiler cycling when there is no load, in other words when the room stat has switched the pump off. It's particularly noticable at this time of the year when the weather is changeable. Yesterday we arrived home at 5 pm, the pump/rads were off but the boiler was thundering away happily.

In the wiring diagrams for the boiler there is a Standard wiring diagram which includes the room stat which is how it is now. There is also a diagram labelled 'Off On No Demand' which includes a cylinder stat. If I fit a cyl stat and wire accordingly will this stop the cycling completely or only when h/w is selected? I only want the boiler to fire when the cyl stat and room stat asks for it.

Thanks.

 

[Agile]

It seems that your system uses a gravity hot water circulation and the boiler just cycles as required to provide that.

I dont know how your system is currently connected and it may be possible to just make a change to the programmer.

Otherwise it will be necessary to rewire the system to include a cylinder stat to ensure the boiler goes off when the water is hot.

Tony