Honeywell ST900S --- fualty not working. Am i an idiot?

[MarkAqua]

Got a Honeywell ST900S linked to a wireless receiver and then a wireless basic turn dial honeywell room stat. This is all linked to a new Valliant Combi boiler.

I cant work it out for the life of me as to why the following is happening :

Which basically is... It will only work in Contstant heat mode, not Auto or Once. Unless you turn the room stat down, flick off the fused spur and kill power to all boiler and controls, turn it back on and hey presto! It fires up as if nothing was wrong.

I have programmes set up on it to come on at 0600 and off at 09:30 back on at 1530 and off again at 21:30

If the Mrs is in with the kids during the day she would like to just flick it override mode or Extra hour.


PLEASE HELP ME OUT AND STOP HER MOANING AT ME! I cant take it any longer haha

 

[doitmyself]

Got a Honeywell ST900S linked to a wireless receiver and then a wireless basic turn dial honeywell room stat. This is all linked to a new Valliant Combi boiler.

Who installed the programmer and stat? If the same person as the new boiler, get them back to sort it out.

If you did the install, where does the receiver get its power from?

The S version is intended for Rental properties. It will shut the boiler off when the Annual Gas Safety Certificate is due.

 

[MarkAqua]

Council did it as we were renting at the time, but have since bought it so its my responsibilty now DOH! To be fair I was thinking of changing the lot to danfoss, but I still want it working for the time being...

It gets its power from 240V SF from the sockets ring.

It isnt showing the message of inspection due.

Thank you for the reply

 

[doitmyself]

Will the boiler light if you press the override button on the receiver? Check Constant, Auto and Once.

Does the green light come on when you call for heat using the thermostat? Check Constant, Auto and Once.

 

[MarkAqua]

JNope boiler doesn't light with OR. Green light comes on but the boiler doesn't fire.

 

[doitmyself]

Nope boiler doesn't light with OR. Green light comes on but the boiler doesn't fire.

Did you check with the ST900 in all three positions (Cont, Auto, Once)?

If you did and you get the same result in all positions, the receiver may be faulty. Here's how you check:

Take normal safety precautions (elecy off!).

Remove receiver from back plate
Insert a link between A and B on the receiver
Turn power back on.
The boiler should light immediately.
If it does the receiver is faulty; if not, it's a boiler fault or dodgy wiring between receiver and boiler.

 

[MarkAqua]

Thank you. I will do this the weekend. I appriciate your help