Glowworm Compact 80E No Ignition

[MrSDog]

My Compact 80E has stopped igniting. It goes through the fan sequence and the spark ignitors fire with DHW and CH demand OK but no flame.

I am assuming that the gas valve is not opening.

The PCB looks to have a section next to the transformer around the rectifier diodes where it has got hot.

The Valve is a Honeywell VX4105G but I cannot find any info on the net.

The PCB is a Honeywell 45.006.545-001 rev G same again I cannot find any info on the net

Without wanting to wreck a new PCB if the Gas valve is at fault I have the following questions.

1:- Does anyone have a spec sheet or wiring diagram for this valve/PCB or a full schematic for the boiler?

2:- Does anybody know what resistance values in ohms I should expect from the two solenoid coils on the valve ?

3:- Will the new PCB require the burner pressures setting up with the potentiometers on the PCB or should it just match the valve anyway?

Many Thanks

MrSDog

 

[namsag]

Installation instructions with wiring diagrams avialable on glowworm web site

 

[Rob]

Just changed one a few days ago.

Look for approx 110 vac between the red and black (possibly blue and brown) in other words not the white and black wires on the gas valve. During sparking.

If so its sticking as was mine. A gentle tap at the back may get it going but it will need replacing, by someone competent with gas!

very rough guess at the solenoids would be around 2k each.

 

[MrSDog]

Just changed one a few days ago.

Look for approx 110 vac between the red and black (possibly blue and brown) in other words not the white and black wires on the gas valve. During sparking.

If so its sticking as was mine. A gentle tap at the back may get it going but it will need replacing, by someone competent with gas!

very rough guess at the solenoids would be around 2k each.

Cheers rob884

I have 1.6K black to white and 2.6K Red to Blue Are these the two solenoids? If so they're not shorted or open
I'll refit PCB and power it up to test volts

 

[MrSDog]

Ok I now have refitted PCB between Red and Blue I have 55Vac when ignitors firing. Going to try new PCB.

Cheers for your help guys

 

[MrSDog]

Just to wrap this thread up:-

Changed PCB and now all working. Got PCB from ebay it was an updated version which included a replacement DHW thermistor to mount on internal pipework in boiler replacing original thermistor unit mounted on diverter valve.

Hot water performance has never been better than now i.e able to use a lot more DHW flow with minimal temperature drop so I am well happy as is Mrs S Dog.

Off now to sort out latest problem with diverter valve leaking at motor end which probably blew the original PCB

Thanks again for your assistance

Mr S Dog

 

[Rob]

While im pleased its all working again, this PCB usually requires setting up for gas pressures, obviously high enough for HW but set too high for HW HTG or ignition will reduce the boilers life.

rob

 

[MrSDog]

Thanks

I'll give a local corgi a shout to set pressures up