Vaillant boiler

[Hap123]

My Vaillant boiler central heating comes on by itself when I run hot water. It was doing this for a while and went unnoticed. (I thought that we'd forgot to switch the central heating off manually as it doesn't respond to the thermostat settings). Then we lost
all hot water and called Home Serve out to fix it. The first engineer said it was the exchange unit or something; he didn't carry the part so his colleague would come out the next day to fit one. A couple of days later he came. We now have hot water again but the original problem with the central heating coming on when the hot water is running has returned. We have to turn the electricity off on the boiler to prevent the heating running constantly. Any solutions please?

Thanks.

PS It's a Ecotec plus model

 

[CombustionGuy]

Get home serve back

 

[jeff the gasman]

It's a faulty diverter valve. The hot water pre heat is running your heating.
Get Homeserve back
Jeff

 

[45yearsagasman]

Combi or heat only boiler?

 

[Agile]

I really cannot understand the total incompetence of so many working for firms like Home Serve.

I carry that diverter valve in my car so surely they should in their van?

Turn the hot water knob anti clockwise and then up to about 2/3 of the range and that should turn off the DHW preheat.

Tony

 

[Dan Robinson]

What if he'd used it earlier in the day?

 

[Phill Peck]

I really cannot understand the total incompetence of so many working for firms like Home Serve.

I carry that diverter valve in my car so surely they should in their van?

Turn the hot water knob anti clockwise and then up to about 2/3 of the range and that should turn off the DHW preheat.

Tony

You carry all vaillant diverter valves in your van tony???

He hasn't specified the model

Not sticking up for homeswerve but c'mon

 

[45yearsagasman]

Can anyone tell from what's been posted, that this is a combi. Have I missed something, or are you all better guessers than me?

 

[Dan Robinson]

central heating comes on by itself when I run hot water

'Twas my clue.

Implies it is a fairly rapid occurrence.

 

[Hap123]

Thanks to everyone for your useful replies. I've called Home Serve back and am awaiting a reply from their engineer for a return visit. Will keep you posted on the result.

 

[Bunnyman]

May well be pcb as well as we know

 

[The831Bunny]

Either the DV motor is unhitched from the valve spindle, or the motor and PCB are shot from the DV leaking. Good luck with Homeswerve.

 

[transam]

edit

 

[45yearsagasman]

central heating comes on by itself when I run hot water

'Twas my clue.

Implies it is a fairly rapid occurrence.

I'll get me coat