WB heatlave not responding to stat requests - otherwise working

[HandyAndy20390]

Worcester heatslave 15/19 (est 20 yr old)

Not responding to stat requests - otherwise working in all other respects

new stat tested, has worked for a time, then stops responding so intermittent issue


Adjusting the heating level dial will still fire it up & it will finish its run till up to adjusted temp


Am I to suspect a PCB / component issue ?

Any suggestions much appreciated, thanks

 

[Harry Bloomfield]

Not responding to stat requests - otherwise working in all other respects

new stat tested, has worked for a time, then stops responding so intermittent issue

What sort of stat? If a wireless one, is it within range/how are the batteries?

 

[denso13]

Any suggestions much appreciated, thanks

Are you able to test the stat is actually calling for heat?

 

[HandyAndy20390]

Hi thanks for your quick responses

I went and got a honeywell style super basic 3 wire analogue dial one

I have a multimeter so i guess i'll test for an output

Between now and then if any other ideas come to mind - by all means fire away !

 

[CountryFan]

How does it respond? Check for the neutral wire connection and check if live and switched the wrong way around

 

[ericmark]

Most boilers, heat pumps, etc, do not like fast cycling, so most thermostats have something to stop it. Be it a little resistor which heats up the thermostat when turned on, or some electronic part, there is normally something which results in a delay, while not affecting the temperature. Also, years ago before the condensing boiler, we had thermostats which used a mark/space ratio to gradually reduce the heat output to try and reduce the hysteresis.

Oil boilers need longer to start and finish, so many thermostats have a setting, mine is clearly set for oil and use of radiators, and this changes the minium burn times and restart delay, it will depend on thermostat make and model Nest Gen 3 shown here.

So step one, is what you're experiencing a fault? Or is it a feature? I did have a problem with this thermostat, where it would lose wireless connection with the base, and fail to turn heating off, the base

did have lights on it, so it was plain to see the thermostat was the problem. More expensive models will auto turn off if no signal every ½ hour.

Start point, is read the instructions, and see what it is designed to do. And if you can put a link to instructions it saves us also hunting for them.