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Andrew Smith
Andrew Smith, HVAC Technician
Category: HVAC
Satisfied Customers: 3586
Experience:  City & Guilds Plumbing and Heating Engineer
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I have a Vaillant 831 which recently stop igniting the

Customer Question

Hello, I have a Vaillant 831 which recently stop igniting the spark sequence is taking place but it's still not igniting. Help please.
Submitted: 1 year ago.
Category: HVAC
Customer: replied 1 year ago.
(Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from yo. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Andrew Smith replied 1 year ago.
Hi my name is ***** ***** I will try and sort your problem in the shortest possible time.
Can you tell me how long from when the fan starts to when it locks out?
Customer: replied 1 year ago.
The fan runs for 5 minutes while the ignition sparks
Customer: replied 1 year ago.
The fan starts imedectly I switched the boiler and go to a lock out after 5 to 6 minutes
Customer: replied 1 year ago.
What do I have to do to get this working
Expert:  Andrew Smith replied 1 year ago.
Does it ramp up and down a couple of times before lock out?
Can you hear it trying light - like ticking?
Customer: replied 1 year ago.
Yes
Customer: replied 1 year ago.
I can see the spark
Customer: replied 1 year ago.
And it will try to light but gose out instantly
Expert:  Andrew Smith replied 1 year ago.
Does it light at all?
It sounds like it does not know it is lit even if it lights.
You may just need your electrodes cleaning to produce a hotter spark and let the PCB know it is lit.
You will get these cleaned as part of a boiler service (at least you should do)
Customer: replied 1 year ago.
I will try this and get back to you by Monday thanks
Expert:  Andrew Smith replied 1 year ago.
No problem - come back if you get stuck
Customer: replied 1 year ago.
Ok I will let you know by tomorrow
Expert:  Andrew Smith replied 1 year ago.
Ok, thanks
Customer: replied 1 year ago.
I have cleaned the spark electrode and the heat exchanger still not working is it anything to do with the daveter valve
Customer: replied 1 year ago.
I have cleaned the spark electrode and the heat exchanger still not working is it anything to do with the daveter valve
Expert:  Andrew Smith replied 1 year ago.
No, if the divertor valve was faulty it would not even try to spark.
With the cover off can you see if it actually lights at all?
Customer: replied 1 year ago.
No
Customer: replied 1 year ago.
Could it be the gas valve
Expert:  Andrew Smith replied 1 year ago.
It could be if the pilot is not lighting at all.
Have you tried using a match when the boiler is trying to light?
Customer: replied 1 year ago.
No how am going to do that when the heat exchanger is sealed and close
Expert:  Andrew Smith replied 1 year ago.
Ok, can you take the spark electrodes out and see if they spark when you try and restart.
Can you check the gas valve for voltage when trying to light?
Customer: replied 1 year ago.
Ok I will try this first thing in the morning when I am at the property tomorrow.
Expert:  Andrew Smith replied 1 year ago.
Let me know

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