Vaillant Ecotec Plus 615 burner on without call for heat

[copea]

Hoping someone can help please?
We've just had a Vaillant Ecotec Plus 615 installed and the electrician and installer are slightly flummoxed.

It is a Honeywell S-plan system.
There is no call for heat (0V to the 'RT' terminal) but the boiler is maintaining the flow at 75c (through the internal bypass, so with the burner modulating down very low).

I've checked with a multimeter and the output down the wire connected to the 'RT' terminal is correct (i.e. 0V when timer is off, 0V when timer is on and there is no call for heat, 240V when timer is on and there is a call for heat).

Does anyone have any idea what could be causing this?

Thank you.

 

[ScottishGasMan]

24v link has been left in. Get the installer to check that, you shouldn't be in near the electrics at all as you need to disturb a sealed chamber to get to the electric connections

 

[copea]

Thank you. I'll ask them to check that.

I checked at the wiring centre, not within the boiler as I'd been told which colour wire went where on the boiler.

 

[Dan Robinson]

Nothing like reading a manual every so often.

 

[Storms]

Hoping someone can help please?
We've just had a Vaillant Ecotec Plus 615 installed and the electrician and installer are slightly flummoxed.

It is a Honeywell S-plan system.
There is no call for heat (0V to the 'RT' terminal) but the boiler is maintaining the flow at 75c (through the internal bypass, so with the burner modulating down very low).

I've checked with a multimeter and the output down the wire connected to the 'RT' terminal is correct (i.e. 0V when timer is off, 0V when timer is on and there is no call for heat, 240V when timer is on and there is a call for heat).

Does anyone have any idea what could be causing this?

Thank you.

looks like the thermostat's been wired incorrectly.

 

[copea]

Fair comment Dan, although the electrician was berating the installers' manual for being very vague!

And Storms, I've eliminated that as the source of the problem.
It was indeed the 24v jumper as SGM suggested.

Thanks all.

 

[Dan Robinson]

Electricians shouldn't be let near a boiler.

The instructions are perfectly adequate if you know what you're doing.

 

[copea]

Haha!

[...]if you know what you're doing.

And therein lies the problem!...

 

[Dan Robinson]

He's charging you for the work. If he's poking around the wiring centre of the boiler, then he should be gas safe registered, or someone who is should be with him.

Although, to be fair, if the heating man can't wire house own boiler, is be worried.

 

[ScottishGasMan]

He's charging you fit the work. If he's poking around the wiring centre of the boiler, then he should be gas safe registered, or someone who is should be with him.

Although, to be fair, if the heating man can't wire house own boiler, is be worried.

Never understood how people can get into fitting and even repair with zero electrical knowledge, it's literally the first thing the gas board teach after the basics on boilers.

But in this case it's just someone unwilling to read the instructions, not that gas fitters would need those lol