Very Strange WB oil heatslave boiler problem?

[Mike25]

Hello All,
After trying WB website and two local heating engineers (both failed) i'm hoping someone here has heard of this before?
Problem... Boiler seems to work fine on/off etc but.... If my CH and HW are on, the CH will only fire if I switch the HW off, now just to explain further…. if they are both off and I turn the CH on, it wont work until I turn the HW on then off again, it's as though the switching off of the HW triggers the pump for the CH. I've been told the programmer ( WB twin channel) is fitted and wired properly.
I hope I've been clear enough, like I said, seems to be an unusual problem?

TIA
Mike

 

[Terrywookfit]

Ten minutes with a multimeter should identify the problem.

Which model heatslave is it.

 

[Mike25]

12-32 RSO

 

[Terrywookfit]

12-32 RSO

????????????
Are you sure ?
I have only seen 12/14 or 12/18GS or 25or 26 /32

 

[Mike25]

Sorry Terry, i'm just going by the paperwork, everything was here when we bought the house, it says Heatslave 20/25 on the front of the machine?

 

[Terrywookfit]

OK
If you turn the h/w control stat to off (anticlockwise), does the heating work.

 

[Mike25]

No, not unless you press the programmer button to turn the HW off

 

[martyndc88]

I'd say either sticking relays in programmer or faulty diverter actuator

 

[Terrywookfit]

Is this a recent fault or an ongoing one ??
As I said previously...10 minutes on site with a multimeter and circuit diagram would identify the problem.

Find a oil Tech who is familiar with this models operation....Otherwise you will just be making wild guesses.

 

[Mike25]

Cheers guys, i'll get a pro out who knows this model.

 

[ericmark]

I will guess Y plan and micro switch stuck in the motorised valve head, likely if you move bleed lever to bleed and latch heating will work, but if left in summer CH will get warm when heating DHW.

 

[Terrywookfit]

I will guess Y plan and micro switch stuck in the motorised valve head, likely if you move bleed lever to bleed and latch heating will work, but if left in summer CH will get warm when heating DHW.

It's a fookin HEATSLAVE !!

 

[oilboffin]

You need a good sparky who's well up with electronics to Id the fault then the engineer knows what he's got to do,I use one who diagnoses tricky faults for me saves a lot of time,I'm ok with most things but this guy sorts out the brain busters for me. Bob

 

[Terrywookfit]

You need a good sparky who's well up with electronics to Id the fault then the engineer knows what he's got to do,I use one who diagnoses tricky faults for me saves a lot of time,I'm ok with most things but this guy sorts out the brain busters for me. Bob

I was a TV eng in a previous life so these boilers don't faze me.

 

[oilhead]

Faulty programmer; common fault on these boilers. A multimeter will prove it.
I'm assuming you have a built in programmer