Heating keeps coming on by itself (Vaillant ecotech 637)

[Jim Maule-Ffinch]

Hi all,

Our Vaillany ecotech 637 boiler fires up and rads come on even though thermo in the house is at lowest setting eg it's not requesting the heating. Its driving me mad as its completely unpredictable.

Could anyone please suggest a way to fix this?

Many thanks

Jim

 

[terryplumb]

What type of stat ,wireless ?

 

[picasso]

Also can you post a pic of your zone valves ?

 

[Jim Maule-Ffinch]

It's a wireless stat, but the Danfoss RX1 receiver light does not come on, so I don't think it's a rogue stat. But then again I don't know what I'm talking about!

 

[Jim Maule-Ffinch]

Pics....

 

[Jim Maule-Ffinch]

More pic

 

[terryplumb]

One of the motorised valves controls your central heating and it is likely faulty .( The other one controls the hot water cylinder).
Edit..
One of them looks like a 3 port valve,do you have different heating zones ?

 

[D_Hailsham]

One of them looks like a 3 port valve,do you have different heating zones ?

The silver valve at the front is a V4043 zone valve; I can't read the red one as it's too blurred.

 

[terryplumb]

The silver valve at the front is a V4043 zone valve; I can't read the red one as it's too blurred.

Yes ,the red one looks like it has 3 ports. Difficult to see but can just make out "T" shape diagram on it with what looks like ports ID ??

 

[Jim Maule-Ffinch]

All, some more pics. Thanks for the interest.

 

[terryplumb]

Thanks ,it's not a 3 port .Thought that would be a weird set up if it was.
The red motorised valve is providing a switched live to the boiler ,it's duff.
Engage an engineer to refurb / replace it.

 

[Jim Maule-Ffinch]

Do we have different heating zones? Not that I'm aware of. We have just the one stat in the hall. Cheers, Jim.

 

[Jim Maule-Ffinch]

New update. The rads are now getting warm even when the boiler is not firing up in heating mode, or when it's not firing at all. This seems to happen after hot water has been drawn off through taps etc (bath/shower) although not every time. Bizarre!

 

[picasso]

How old is your boiler ? (just wondering if the 24v link has been left in)