Baxi 105e Gas Valve....... One for Poxi?

[vern]

I am sure there was a post about this before but here we go....

Callout to 105e in a loft no light etc, boiler on lock out no gas fault 30 deg led flashing etc, gas at inlet so thought valve had stuck as house had been empty 8 weeks, banged no joy!

240v at pins 2 and 4 of pcb so, i get a new gas valve as the multi plug on the valve aint easy to get test probes in and in a black loft working via head torch, anyhow gas valve swapped, same fault so test continuity of wires from pcb plug to plug on gas valve, wire is approx 18" long, neutral and earth fine, but nothing on live, this is when i notice the plug on the gas valve has some sort of recitifer built in, its sealed so no chance of a look.

Ordered a new lead with plugs , that also feeds the spark gen.

Anyone else been caught with this? is the gas valve DC? forgot to look after i left job, or is there a diode in the multi plug that has failed and the valve is AC? NOT THE MODIREG i know this is DC and is fed via 2 other black wires!

 

[tom609]

yes the valve is dc to stop it buzzing apparently, was chatting to a heat team engineer in hrpc about similar prob though i had fettled it by then but was curious, there is a little pcb in the gas valve connecting plug

 

[vern]

yes the valve is dc to stop it buzzing apparently, was chatting to a heat team engineer in hrpc about similar prob though i had fettled it by then but was curious, there is a little pcb in the gas valve connecting plug

so did the new lead with plug sort it tom? as that is all i can think it is......gonna cut the old one open

 

[tom609]

it was actually the valve though i had a new cable with me in case

 

[vern]

it was actually the valve though i had a new cable with me in case

lol cable is cheaper, but not when you have fired a gas valve in, that will teach me...thing is i read MI's after it does not even mentioned cable....gas valve then pcb typical

 

[R1CKY]

Had it a few times, got caught out myself too!

 

[buckley plumb]

i posted one on here similar changed the lead and gas valve andvoltages were ok and the 12v to modulator so flame should have been full power but didnt never got to the bottom of it.baxi told me it was impossible to get true reading from that that magic ac/dc lead

 

[tom609]

i agree

 

[vern]

Right update....fitted lead problem solved, had more time so put old valve back in, lockout, put new gas valve back in job sorted, set up a high and low sorted......theory gas valve took out PCB in lead eventully....

cut old plug open and indeed PCB in there looks like a basic capacitor smoothing circuit for noise suppression, components all black and smelly, got a pic will upload later!

one to remember boys!

yest ant voltages at plug mean bobbins, you cannot even test continuity of wires to pin, tried weather you buzz the live or neutral at PCB plug, you get continuity on the outer top pin, obviously the PCB screws the readings!

lead part no is 248218 for future ref

 

[vern]

Picture of said plug as promised....toast