Hi all,
First time posting. I've searched through forums but am still at a complete loss so any help would be massively appreciated!
My 6 yr old Glow worm 30C is not providing heating or hot water for more than 40s before the burner switches off, goes through a purge cycle and then restarts with the same effect again.
There are no fault lights.0
I have tested the pressure switch and fan air pressure switch and neither of these are responsible for the burner shutting off.
The Temperature indication never gets above 40 when the trip occurs and I have removed the temperature transmitters from the pipes during operation to make sure the shut-off is not been caused by a high temperature.
I have also proven that the condensate system is working ok and that the high level switch isn't responsible.
The boiler doesn't enter a lock out condition after the trip, but for completeness I have also monitored the limit thermostat switch circuit during the Trip and that is not the cause.
I rang the Glow-worm technical line and they advised that it looks like a PCB fault. PCB replaced and still the same issue... I've also tried a different controls potentiometer PCB and still not resolved.
I have noticed that if I remove a connection from the gas valve modulator solenoid, the boiler operates in a low firing mode without problem. As soon as I reconnect (after it's been running for 40s) the burner trips off without warning light. When I measure, the PCB is trying to send approximately 34V to the valve.
I'm leaning towards replacing the gas valve, but am a little concerned about throwing more money at it (I will pay a Gas Safe engineer to replace the gas valve).
I believe I have ruled out the hydraulic system being at fault as all of the temperatures and pressures have been monitored and tested to prove they are not the cause. The flow switch clearly is not a cause as the fault is there on CH too.
The burner ignites straight away and flame looks good. It will also regulate during the first 30s of operation. The ignition sensor looks ok and I would expect to give a fault condition if it were responsible for shutting off the boiler.
The Diverter valve is functioning properly - I can hear it moving to position and the correct pipes are getting warm.
So after all that...
Any ideas for further tests?
Similar faults seen elsewhere?
Should I have the gas valve replaced or am I on the wrong track here?
Thanks for your help!
P.S. my house is being sold and I'll be moving in 3 weeks time... Not good timing for this!
First time posting. I've searched through forums but am still at a complete loss so any help would be massively appreciated!
My 6 yr old Glow worm 30C is not providing heating or hot water for more than 40s before the burner switches off, goes through a purge cycle and then restarts with the same effect again.
There are no fault lights.0
I have tested the pressure switch and fan air pressure switch and neither of these are responsible for the burner shutting off.
The Temperature indication never gets above 40 when the trip occurs and I have removed the temperature transmitters from the pipes during operation to make sure the shut-off is not been caused by a high temperature.
I have also proven that the condensate system is working ok and that the high level switch isn't responsible.
The boiler doesn't enter a lock out condition after the trip, but for completeness I have also monitored the limit thermostat switch circuit during the Trip and that is not the cause.
I rang the Glow-worm technical line and they advised that it looks like a PCB fault. PCB replaced and still the same issue... I've also tried a different controls potentiometer PCB and still not resolved.
I have noticed that if I remove a connection from the gas valve modulator solenoid, the boiler operates in a low firing mode without problem. As soon as I reconnect (after it's been running for 40s) the burner trips off without warning light. When I measure, the PCB is trying to send approximately 34V to the valve.
I'm leaning towards replacing the gas valve, but am a little concerned about throwing more money at it (I will pay a Gas Safe engineer to replace the gas valve).
I believe I have ruled out the hydraulic system being at fault as all of the temperatures and pressures have been monitored and tested to prove they are not the cause. The flow switch clearly is not a cause as the fault is there on CH too.
The burner ignites straight away and flame looks good. It will also regulate during the first 30s of operation. The ignition sensor looks ok and I would expect to give a fault condition if it were responsible for shutting off the boiler.
The Diverter valve is functioning properly - I can hear it moving to position and the correct pipes are getting warm.
So after all that...
Any ideas for further tests?
Similar faults seen elsewhere?
Should I have the gas valve replaced or am I on the wrong track here?
Thanks for your help!
P.S. my house is being sold and I'll be moving in 3 weeks time... Not good timing for this!
