Ravenheat 82e combi boiler fuse keeps blowing

[adam911]

Hi i was wondering if anyone can help. I came to use my hot water the other day and noticed there wasn't any power to the boiler. Checked the pcb board and the 2 amp was blown so i replaced it and it blew again.

Things ive done.

Disconnected the pump to the board and the fuse still blew so not the pump.

So i removed the ignition board away from the gas valve which has a 4 pin connector pushed in the back of the board and the fuse didn't blow.
The ignition board has the aps and fan connected to it and the fan was running but if i was to pushed the board back into the gas valve the fused would blow.

So my question is would it be the gas valve causing the short or the ignition board. The fuse on the ignition board never blows it the 2 amp fuse on the main pcb board that blows

Any advice would be much appreciated.

 

[hertsboilers]

Gas valve.

 

[adam911]

So its the gas valve. How does it work inside. I thought it was just a relay that opens and closes the gas so the relay is always live so how would it short if all terminals in the relay are live?

Thing is if i connect the ignition board back to the gas valve but disconnect the fan it doesn't blow the fuse so wasnt sure if it would be ignition board or gas valve.

I did open the ignition board and there is a bit of black like charcoal on the one of the 4 pins on the board that go into the gas valve.

 

[hertsboilers]

Fan then

 

[adam911]

Yes but the fan is running when you disconnect it from the gas valve so it wont be that. Checked the resistance on the fan and im getting 53 ohm which is fine.

 

[hertsboilers]

Lol, the board.

 

[adam911]

Ok board it is. Any idea how does the gas valve work so i can get a better understanding. Is it just a relay which opens and closes. On the manual diagram it does show the diagram of the bit where the ignition board connects to the gas valve.
I've uploaded a pic of the diagram

 

[steve32]

Just change the fan, gas valve and pcb, skip the boiler or get an rgi to diagnose the fault and safely fit the new part.

 

[Agile]

The gas valve does not contain a relay.

It has two solenoids!

I would advise getting an RGI.

Hardly worth repairing such an old boiler!

 

[AGAS]

you seem to be messing around with boilers a lot are you registered ? if so you will find out how much you really don't know if you join the cc , but practicing on customers boilers with help from forums is not clever if your not registered .

 

[adam911]

Agile would the gas valve blow the 2amp fuse in the main pcb board. I know its not the pump or fan blowing it as ive had the pump disconnected and it still blew the fuse but if i have have the board away from the gas valve solenoid the fan runs so wont be fan.

I know its a very old boiler but if its just a simple fix i would rather not have the boiler changed.

Agas this is my own boiler and not a customers.

 

[Agile]

Most would say a replacement gas valve fitted by a registered engineer would be about £300 and not worth the cost.

As you like fiddling with boilers when not gas registered, I am a little hesitant to reply at all.

I have encountered a gas valve where the winding was shorting to the earthed casing even though the winding was still intact and operating the valve!

 

[AGAS]

Agas this is my own boiler and not a customers.

I'm talking about all the other boilers you've been working on

 

[adam911]

Ive only had this boiler that im working on if u look at my previous post i had a stuck diverter valve previously on the same boiler.

I dont mind having a go at changing boiler parts ie fans diverter valves etc im not breaking the law.. but wouldn't touch anything to do with gas. So if i do need to change the gas valve its time to call in gas safe engineer.

Is there anyway to test the solenoid with a multimeter before i call someone out. I can get a new gas valve for £60 new so will it cost £240 for labour

 

[adam911]

Agile should there be any continuity between the 4 pins on the gas valve solenoid as i checked for continuity on all 4 pins one at a time and there wasn't any continuity whichever pins i put my multimeter probes on. Thanks for your help i know your the man and you know your stuff after reading your replies on other posts.