The background and problems on my central heating system are as follows:
The boiler is wall mounted and located within an integral gagrage. It is fitted with a frost, which is set to 5 deg C. The internal thermostat is set to high for the winter period.
The roomstat is a digital wired thermostat sited on the 1st floor landing. It's temperature is set to 22 deg C.
The central heating and hot water are programmed to come on twice a day for around 4-5 hours each period.
The hot water cylinder has had a new honeywell cylinder stat fitted and new honeywell 3 way valve fitted around 7 months ago.
The problem was that when the heating and hot water were programmed to come on, only the hot water would stay on until either hot water was drawn form the system or the room stat was adjusted, then the rads would heat up.
I got the heating engineer out last weekend who fitted the various components last year and he checked them and said they were all operating as they should. He suspects the problem may lie with the wiring set-up of the frost stat and the boiler.
Since he visited, the problem has now changed so that now when the programmer is off, the roomstat temperature achieved, the boiler is still firing up and heating the rads!
I thought it might be a fault on the 3-way motorized valve fitted next to the cylinder, but the heating engineer says it is working fine.
It's very frustrating and puzzling :?: Does anyone have any thoughts as to what is causing these problems and more importantly how we solve them.
Any ideas would be greatly appreciated.