boiler has demand pump and fan run but doesnt go to ignition. am i right in thinking air pressure switch. any help is apresiated
vaillant turbomax plus 824e
- Thread starter 5stargasandoil
- Start date
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You are not right in diagnosing anything without any appropriate tests.
They are a common failure point ( after the diverter valve ) and uniquely located where a DIYer could just about replace it without infringing limitations on DIY work on boilers as it does not need the combustion chamber to be opened.
If you removed it and measured the contact resistance about 10-15 times and consistantly obtained less than 1 Ω then it is probably OK. You only activate the switch by blowing TOWARDS the +ve air connection.
A gas engineer would also measure the applied differential pressure!
It may or may not be cause of the fault!
Tony
They are a common failure point ( after the diverter valve ) and uniquely located where a DIYer could just about replace it without infringing limitations on DIY work on boilers as it does not need the combustion chamber to be opened.
If you removed it and measured the contact resistance about 10-15 times and consistantly obtained less than 1 Ω then it is probably OK. You only activate the switch by blowing TOWARDS the +ve air connection.
A gas engineer would also measure the applied differential pressure!
It may or may not be cause of the fault!
Tony
the home owner tells me that divirter was changed last year. thinking about it does the fan have a venturi as a blockage would produce the same fault. sorry for the silly questions but im only used to the newer condensing boilers
You now seem to be gas registered!
In that case you should register and ask in the Combustion Chamber part of this site where we can give you full information on gas matters.
The forum rules and common sense prevent any information here on repairs beyond the safe scope of a DIYer!
Tony
In that case you should register and ask in the Combustion Chamber part of this site where we can give you full information on gas matters.
The forum rules and common sense prevent any information here on repairs beyond the safe scope of a DIYer!
Tony
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thanks for your help tony. im also new to this forum lark too 
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