Vaillant ecoTEC pro - No heating

[Mr M]

I have a Vaillant ecoTEC pro 28. The house that it is in has undergone some recent refurbishment. The boiler was tested before the work started and was working fine. The only thing that is different now is that the original room thermostat is no longer present as it was damaged during the work. Now, when the heating is switched on, nothing happens. The hot water is fine.

I may be totally wrong here but I am concluding that the boiler 'thinks' that there is still a room thermostat connected to it but as it's now not present, it is for whatever reason not firing up when heating demand is asked for.

I have consulted the operating manual and it refers to being able to 'Reset parameters to factory settings'. I am not even sure whether doing this would actually resolve my problem or even worse, whether it might throw the whole boiler into turmoil?

Before I call someone out, is there anything I can check/try to try to set the boiler back to it not 'thinking' it has a room thermostat still connected to it?

Thanks in advance for any responses.

 

[fezster]

What did you do to the wires which were connected to the original thermostat? They are connected to complete the circuit, so if they have been left unconnected, the circuit will not be complete and the boiler will not fire.

 

[Mr M]

Sorry, just to clarify, I had other people working in the house and it was them who damaged the room thermostat. The guy had already removed it and said that the boiler would still work without a stat being fitted to it. I am not sure if he completely removed the cable at the boiler end or just cut it back. If you can tell me where the cable would have connected into under the boiler, would I be ok to then check whether the cable is still there or not?

 

[Gasguru]

Either tell them to replace the damaged thermostat or you'll get someone in and they can pay.
It wouldn't surprise me if they've buried the wiring back in the wall.

 

[Mr M]

Unfortunatley, I'm no longer in contact with the people who did the work for me...... Long story!

Other than the mains cable, there isn't any other cabling that I can see coming out from underneath the boiler but I suppose he could have chopped the cable back leaving it still connected at the boiler and then just tucked the tail end of the remaining cable up under the bottom of the boiler. That would bear out what fezster said in his post above. If I shine a torch under the boiler, where abouts would the room thermostat cable connect to in the boiler?

 

[Gasguru]

Post pics of the underside of the boiler and wall connection...plug or fused spur etc.

 

[Mr M]

Apologies for the delay in getting the photo below which shows the underside of the boiler. The boiler is connected via a plug at the moment, but it will eventually be wired into a spur unit. The original cable from the damaged room stat appears to have been completely removed.