Need Engineer to fit gas valve in Worcester boiler

[Mloclam]

Hello,
I'm looking for a qualified person to replace the Gas Valve on my Worcester boiler as pictured below. The valve is long obsolete but I have managed to get one so now looking for an engineer.
My location is Royal Wootton Bassett.

 

[Agile]

How are you so sure that the gas valve is faulty?

Most engineers will have no problem fitting a new valve. Some are reluctant to fit used parts though.

Tony

 

[FiremanT]

As per Tony: Who diagnosed the fault?

 

[muggles]

I'm only 30 minutes away from you...I'd want to know the provenance of the "new" valve and the reason why you think it is needed before being even remotely interested in doing the job though

 

[Dan Robinson]

He's guessing it's the valve based on supposition on here.

 

[Mloclam]

Thank you for all the replies and offers of assistance.

While I've been out at the day job wife found a local company who will come and have a look at it. Of course it is up to them to diagnose the problem but at least I have the valve if it turns out to be that.

Problem is that pilot light does not stay lit. Reason for thinking its the valve is that, with the electrical power switched off, measuring between the thermocouple copper sheath and the lead going into the back of the valve I have 30mV and the fault finding section in the Installation and Maintenance Instructions says it needs to be minimum 8mV . (Obviously needed to keep the Operating button on the gas valve depressed to keep the pilot lit while I did this measurement)

Will be delighted if proved wrong and it's something cheaper/simpler.

Thanks,
Malcolm

 

[Agile]

You are missing some understanding of how these things work!

Disconnecting the TC and getting an OPEN CIRCUIT voltage of 30 mV means nothing. Its the on load voltage which is important.

It is much more likely to be the part the white wire goes to which is at fault. But we cannot ask you to look at that as its in a sealed part of the boiler which DIYers should not open.

There are many plumbers who don't fully understand these parts either though. Its easier for them to just say "the boiler is crap" and you need a new one!

Tony

 

[DP]

Disconnecting the TC and getting an OPEN CIRCUIT voltage of 30 mV means nothing. Its the on load voltage which is important.

Rightly so tony, BUT o/c voltage here due to faulty magneto perhaps
Op does say

OP does say
""measuring between the thermocouple copper sheath and the lead going into the back of the valve I have 30mV""

so.......nothing disconnected.