Central heating fault.

[Dave123]

So a customer changed his own stat and wired it wrong and blew 3/4 fuses. Then heating was stuck on so I changed the programmer and this resolved the problem so I think the short circuit had damaged programmer.
Now 5 days later the the hot water isn’t heating haven’t been yet. All I can guess is the cylinder stat or zone valve could have problem.

Any ideas?

Thanks

 

[bigspark17]

Yes, go there with the proper test equipment and identify the fault.
How familiar are you with heating systems, isit a y or splan?

 

[davesparks]

Then heating was stuck on so I changed the programmer and this resolved the problem so I think the short circuit had damaged programmer.

Did you test it first before replacing it or was it a bit of guesswork?

How do you think a short circuit may have caused damage to the programmer?

 

[Dave123]

The live at room stat was permanently live regardless of the position on the programmer. The programmer was always calling for heating even when In off position. So I tried a new Drayton programmer and heating was fine.

Thanks

 

[Dave123]

My heating experience isn’t huge. It’s an S plan.

 

[bill01803]

I have had many programmers welded on by short circuits

 

[Dave123]

So I’m wondering if that could affect cylinder stat or zone valve possibly?

Thanks

 

[littlespark]

You need to do some live testing.

Is power going to the stat when calling for heat?

Is power coming back from stat when cold?

Does manually opening the zone valve bring it on?


A major short circuit may have damaged more than the programmer, but you need to test thoroughly rather than playing parts bingo.

Do you know what the customer had done? If he wired the stat wrong, I would expect this stat to bear the brunt of any fault, not the programmer some distance away….

 

[brianmoooore]

Did you change the programmer like for like? The base is sort of standard, but the wiring connections vary.

 

[Dave123]

You need to do some live testing.

Is power going to the stat when calling for heat?

Is power coming back from stat when cold?

Does manually opening the zone valve bring it on?


A major short circuit may have damaged more than the programmer, but you need to test thoroughly rather than playing parts bingo.

Do you know what the customer had done? If he wired the stat wrong, I would expect this stat to bear the brunt of any fault, not the programmer some distance away….

I suspected the programmer as the room stat was still live when the programmer was off.

I will check those things you said.

Thanks

 

[Dave123]

Seem the hot water 2 port valve is also faulty. It moves accross but it doesn't make the orange become live so the boiler isn't firing up. So hopefully this is it fixed once I get hold of a new valve.

thanks