Flame rectification

[bassmonster]

How would you diagnose this to determine it's faulty?

 

[Rickster123]

What do you mean??

 

[bassmonster]

Sorry, I mean the flame sensing probe...

 

[stussy]

Turn off gas, call for heat or hot water, if boiler goes to lockout it's working.

 

[bassmonster]

Thanks for that stussy... So there's no need to check resistance or anything?

 

[Ch4 plumbing]

Run boiler (burner lit) then isolate the gas and the boiler should try to relight then go to lockout.

 

[stussy]

No, you just need to prove if it's working or not.

 

[Dotty]

Disconnect the probe. Set your multimeter to microamps. Connect the probe to one lead and earth the other lead. Fire up the boiler, you should see 6-9 microamps. If you do its the board, if not it's the probe or a bad earth.

 

[bassmonster]

Please correct me if I'm wrong. If the probe is faulty, the boiler would go into lockout any way right? So turning off the gas wouldn't determine the probe being faulty? Confused. Com

 

[Dotty]

Did you read what I just wrote?

 

[bassmonster]

Thanks croppie. When you say disconnect, I take you only mean remove it from the burner but leave it plugged into the Pcb?

 

[Dotty]

Disconnect it from the PCB. Leave the probe where it should be.

 

[bassmonster]

I get now.... Thank you.....

 

[bassmonster]

Did you read what I just wrote?

I posted that before I saw your post [emoji5]

 

[Billy Bob Bob]

you should be looking for reversed polarity first though,otherwise it will fry the new pcb

 

[bassmonster]

you should be looking for reversed polarity first though,otherwise it will fry the new pcb

What will fry it, the test that croppie mentioned?

 

[Billy Bob Bob]

What will fry it, the test that croppie mentioned?

no,croppies test is correct, the fact that there could be other factors causing the fault,if any electrical work has been done in the house,and the polarity has been reversed this most commonly shows itself as a flame detection fault ,if you dont test for it and think its the pcb you could get your fingers burnt,what supplies the boiler spur or plug?

 

[bassmonster]

Makes perfect sense.....I'm not looking at a boiler with fault, just picking brains.... Thanks gas man..

 

[Dotty]

Also as I said, check you've got a good earth.

 

[bassmonster]

I remember seeing that pic a few weeks ago. I went out and bought a volt pen the next day....

 

[Kevin D]

Or interrupt the connection between the probe and the harness with your multimeter.

Some newer boilers will give a readout of the ionisation signal on the board display, some need a stronger signal than Croppie quotes.

Worcester quote 35 micro amps on their new compact, I think they have got that wrong though. I can make one run while its reading 15.

 

[stussy]

Sorry, I thought you were asking to check the FFD was doing its job

 

[lame plumber]

only look at remeha avantas, then just press the plus button 5 x and it shows you the flame rectification readout