Valliant eco tec 937

[Matthew Taylor]

Hi. I have a valliant eco tec 937 that keeps firing up to temperature although neither the heating or hot water is calling for heat. The boiler will run up to temperature without circulation then switch off. The screen is showing the radiator symbol continually. Any ideas, possible wiring?

 

[ianmcd]

what controls do you have ? thermostat timer programmer etc post pics of what you have

 

[Matthew Taylor]

Drayton lp241 and standard room stat and cylinder stat. There is a separately controlled underfloor heating circuit on its own zone and controlled via heatmiser

 

[ianmcd]

you will have zone valves it is likely that one has seized and the micr switch is sending a false signal to your boiler, or the micro switch on one of them might be stuck

 

[Matthew Taylor]

Will check this later. Possibility as I have had to change one already

 

[Matthew Taylor]

Solved, the installer left link 24 on the PCB board installed. This is for the 24v thermostat.