Vaillant combi, danfoss thermo. Sometimes heating does not come on.

[RandomGrinch]

Sorry dude, don't know where the receiver is

You should have a box looking a bit like this mounted somewhere?

 

[baggister]

I just found the receiver (never knew it was there in all the five years we had the boiler), On wall above the boiler, near extractor pipe - behind a covering. I clicked up on thermo, and there was a click from the receiver. Think one of the lights of the receiver came on.

 

[RandomGrinch]

never knew it was there in all the five years we had the boiler

Now you know where it is, as said before, if the boiler doesn't respond to the thermostat...

check if the receiver by the boiler is responding to the signal

It may be, that there could be some interference effecting the signal from the thermostat in certain locations?

It wouldn't help if the receiver was hidden beneath a cover!

 

[baggister]

Now you know where it is, as said before, if the boiler doesn't respond to the thermostat...

It may be, that there could be some interference effecting the signal from the thermostat in certain locations?

It wouldn't help if the receiver was hidden beneath a cover!

Thanks!

Just a matter of waiting now.

I don't think it's interference, since it is guaranteed to not work if I have been away for a week.

The cover is wooden. I'm not sure if the cover makes any difference, as it works quite normally most of the time.

Just speculating : is it possible that if the receiver / boiler hasn't received a signal for a while, (as there are no timer events), maybe the receiver/boiler goes into some kind of energy saving hibernation mode or something? Perhaps I should add some kind of one minute a day timer once a day.

 

[baggister]

OK , been a while now since I made this post. Just came back from 2 days away, clicked the up button on thermo, wouldn't start the boiler. I went up, thermo 6 inches from receiver, pressed again, wouldnt start. The display on thermo looked fine, there was a little flame icon. I pressed the button on the receiver ( two on it, pressed the one to the right), boiler started straight away. I don't recall seeing the "transmit" icon on the thermo display when I pressed the up button on it.

 

[CBW]

When you replaced the batteries, did you use zinc or alkaline?

 

[baggister]

Alkali. DuracellPlus. AA. (although I needed to add a small amount of folded aluminium foil at each end to tighten things, as the batteries seemed a bit loose).