Worcester Bosch 30CDI doesn't turn off

[StanLaurel5]

We have a Worcester Bosch 30CDi, installed 3 years ago and has been working fine. However, woke up the other day to find that even though the stat was set to nil, the boiler was running at max.

A bit of investigation; hot water works as normal via the programmer, but ch can't be controlled at all by it. Stat is clicking on and off happily so nothing mechanical there at least; ch stays on even when programmer is lifted off the wall and disconnected.

I'm thinking there's a stuck control relay on the boiler control board - does that sound plausible?

Thanks.

 

[bengasman]

Is this the conventional model?

 

[StanLaurel5]

Should have said - yes, conventional.

 

[bengasman]

First suspects are the external valves/controls.

 

[StanLaurel5]

OK... That probably takes it beyond any hope I have of sussing it out! External controls beyong the stat & programmer? And which valves...

As you'll have guessed, I'm not a plumber!

 

[45yearsagasman]

Are you describing a heat only or a combi boiler.WB model ident can be confusing.

 

[bengasman]

Are you describing a heat only or a combi boiler.WB model ident can be confusing.

Should have said - yes, conventional.

 

[45yearsagasman]

I'm glad you find a perfectly legitimate question amusing.
The model 30Cdi alone could be anyone of three boiler types,and I wondered if the OP understood "conventional" correctly.

 

[bengasman]

The model 30Cdi alone could be anyone of three boiler types,and I wondered if the OP understood "conventional" correctly.

3 models?

1 combi without zonevalves
2 conventional, with zonevalves
3 ??????????


As for the amusement factor: the were meant to indicate that the should not be taken seriously.

 

[45yearsagasman]

3 models?
1 Combi
2 System
3 Regular.

 

[Gasman77]

1 - 0 to the auld fella Ben!!

 

[bengasman]

1 - 0 to the auld fella Ben!!

 

[Ray84]

id assume its a system boiler but by conventional poster means open vented.
probably your CH zone valve stuck on

Ray

 

[StanLaurel5]

Cor, didn't mean to start a fight!

zone valve stuck on... what's a zone valve (assuming that's not what I'd call a room stat! - and where would I find it?

 

[Gasman77]

id assume its a system boiler but by conventional poster means open vented.
probably your CH zone valve stuck on

Ray

Why would you assume its a system boiler, not open vented?