24 Dec - update - Grundfos pump still runs constantly

[ollski]

If there is 230v on the orange there's no point replacing the pump, just disconnect the feeds and work backwards to see where it originates

 

[Littlemiss21]

oh yeh if its a Honeywell pcb wire center, then I would definitely be suspecting that, surely they can find the fault with a multimeter.

Apologies if I'm incorrect here. The wiring box in the wiring cupboard says Myson on it, and has a 10 junction white plastic 'thingy' where all the wires are wired in.

 

[Littlemiss21]

Is it just the pump running when it's not supposed to or is the boiler also showing a demand?[/QUOTEpump
The pump runs constantly and fires the boiler up every 15 minutes or so.

 

[Littlemiss21]

Is it just the pump running when it's not supposed to or is the boiler also showing a demand?

The pump runs constantly and fires the boiler up every 15 mins or so

 

[GasElectricalRepairs]

If there is 230v on the orange there's no point replacing the pump, just disconnect the feeds and work backwards to see where it originates

Disconnect all components of the wiring and have an electrician do an insulation resistance check of the fixed wiring . Rewire the Wiring centre to the Honeywell circuit diagram for an s plan. The electrician will then be familiar with what to expect and when at each connection in the wiring center.
If it happens again after this , turn the room stat right down.
Does this stop the pump? ( trying to rule out stuck contacts in programmer)
Ask them to wire a switch into the circuit between the brown to the valve and turn this off if the boiler is firing when it shouldn’t.
Better still wire a 2 gang light switch one isolating on the brown to the valve and another isolating orange from the valve microswitch to the Wiring centre.
If your spark does this you can operate the switches . This will give us more to work on.
All the above is an hour or two and no cost in parts.
Get the spark to mark the two switches up and remember the effects of turning each one off. Turn off the brown first then the orange.
Bit to do , but a logical approach that will split up the circuits and rule a few things out.

 

[breadnbutter]

Apologies if I'm incorrect here. The wiring box in the wiring cupboard says Myson on it, and has a 10 junction white plastic 'thingy' where all the wires are wired in.

ok, its just a terminal box, a myson mwb16
the Honeywell ones had a pcb that you wired into and cut links ect depending on system type.

 

[rhinosaw]

Saw someone 's. comments about turning down/off room stat.
I have an S plan which sometimes comes on for no reason, ie timer off etc, I turn the room stat right down, it then goes off

 

[D_Hailsham]

Apologies if I'm incorrect here. The wiring box in the wiring cupboard says Myson on it, and has a 10 junction white plastic 'thingy' where all the wires are wired in.

Can we have the pic of the wiring box, with cover off, which you promised yesterday?

 

[bernardgreen]

deleted ( due to error in memory )

 

[ianmcd]

Hi and thank you. Am I correct in thinking that the Grundfos pump only needs small voltage and will keep running? It might as well be changed, as nothing else left to be changed now.

Its not the pump, your boiler is firing too, it is wired incorrectly

 

[petit_pablo]

One day i'll actually get one of these BG jobs posted on here.

AT what point was the boiler changed in this little drama? It really shouldn't be a difficult fault to find, safe to say it probably isn't the zone valves and it wont be the pump. Unless the new boiler was rewired for pump overrun it wont be the boiler as the promax wouldnt have had a pump over run. If it was rewired, then has it been done correctly?

 

[dilalio]

I can't think of anything else before doing a complete rewire.

 

[Littlemiss21]

One day i'll actually get one of these BG jobs posted on here.

AT what point was the boiler changed in this little drama? It really shouldn't be a difficult fault to find, safe to say it probably isn't the zone valves and it wont be the pump. Unless the new boiler was rewired for pump overrun it wont be the boiler as the promax wouldnt have had a pump over run. If it was rewired, then has it been done correctly?

Hi. The first time the Drayton valve was changed was on 31 October. New boiler fitted 21 November. All ran fine from 31 October until 7 December, when the same fault came back. Vaillant have been out and checked the boiler. - they have confirmed that all is fine with the boiler and the wiring. it has been installed as a 230v 3 wire installation, without pump overun. The old boiler was merely taken off the wall and the new one put up - using the same existing cable - the installers did not go anywhere need the junction box in the airing cupboard. Once this saga is over, I will have the pump run permanent live connection installed - but just darent at this stage with the major issue we are already having.

 

[Littlemiss21]

The wiring in the junction box has been checked and all is in the correct terminals - think it should be all be unwired and re-wired. Each time the engineers have traced the ‘live’ feed in the orange wire in the heating valve - hence all the actuator changes. It’s a case of tracing back the live feed on the orange to the wiring junction box when the fault is live. I will as promised post a pic of the wiring box.

 

[petit_pablo]

Surprised BG havent pulled out the third party interference card yet!

I should think that there is a issue within the wiring centre thats occured at some point during all these valve changes. Its really not a massive job to rewire the airing cupboard.