Vaillant ecotech combi boiler - has hot water no heating

[nzzhang]

Hello,

I have a problem with my boiler and I hope someone here can help! I suspect it's something simple actually but I just don't know what it is.

The boiler (a Vaillant ecotech combi, pic below) was working fine until a blackout hit my block. The blackout lasted a few hours and when the electricity came back on, the boiler turned back on as well. However, while the hot water is working fine, the heating no longer works. I've tried turning the radiator switch to 'on' constantly, turning up the heating temperature, and I've checked the pressure - it's 1.5 so should be fine. I've also tried turning the whole boiler off at the mains and then back on again but it makes no difference. All the radiators have been bled recently and were working fine before the blackout but now all of them are cold.

When I turn on hot water taps the boiler makes a noise and the ignition seems to turn on. But there's nothing, no noise at all, when I turn on heating. There are no error messages in the display - and I've tried pressing all the buttons to see if there's a message including the 'i' button, the reset button (with the flame crossed out symbol) and the plus and minus buttons.

What am I missing? Please help!

Much appreciated.

 

[wannocks]

Press the i button to get the status code. Tell us what you see. S30 or S31means the external controls aren't asking it to be on.

 

[nzzhang]

I pressed the i button, it says S.30, what do you mean when you say external controls are not asking it to be on? How would I go about fixing that?

 

[Echo the husky]

External controls: Programmer and thermostat. Are these set corectly?

 

[nzzhang]

I'm not sure I have a thermostat or programmer. It works on a timer. There is a white box next to the boiler and what could be a thermostat (pics attached). But the thermostat has long lost its batteries and I've never used or programmed it before. Don't understand why the boiler worked OK in the past without having to do anything with this thing but now it's suddenly important?

 

[Echo the husky]

How do you normally switch on the heating if you don't use that (crap and unreliable) programmable room stat?

 

[nzzhang]

I just either use the on/off switch for the heater, or the timer.

 

[Echo the husky]

In that case I expect the stat needs to be bypassed, or better, got working again. Either fit the batteries or (with the power off!) open the reciever, (the cover unclips to reveal the 2 fixing screws) join together the wires in the com and N/O terminals using a connector block or similar. You can stuff the wires together in the com terminal if you wish, but the terminal holes are very small on these units so you might struggle. Switch the power on and it should work again how you were using it before.

I would recommend getting the thermostat working and fitting it to the wall somewhere sensible. Manually controlling the heating could lead to wasted energy.

Edit: these things have a well known fault where the reciever unit recieves the wireless signal and the green light switches on, but the relay doesn't operate so the heating won't come on.

 

[nzzhang]

Thank you! Just one more question: could I just buy a new room stat and somehow get it to sync with the existing transmitter? I did some research online and it's a radio controlled one. I think I'll struggle to find a battery to go into the old one.

 

[Echo the husky]

The old one takes 2X AA batteries

 

[Echo the husky]

The new version of the same model number is not the same unit as they have changed the design. Salus are cheap rubbish and you should replace it with something better if new batteries don't get the old one working. You will need to buy both the transmitter and reciever as a pair. They come as a kit.

 

[Johnmdc]

That stat just takes 2 standard AA batteries if I remember correctly.

Edit beaten to it by Freddo.

 

[Echo the husky]

Yes the lid sort of pulls straight off of the stat.

 

[nzzhang]

Thanks again! I put AA batteries in and it turns on but doesn't sync with the receiver. It seems to be broken at the back. Anyway, I will have to look into getting a new one.

 

[Agile]

You have to follow the procedure in the instructions to get it synced.

Tony