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Apr 20, 2020
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How does a boiler sense the condensate pipe is blocked?. Boiler stopped working. I was told the condensate syphon was blocked and had to be cleared. I wondered how the boiler controls knew this?
 
There are sensors in the heat exchanger that are specific to this fault.
They detect the condensate level in the heat exchanger and hence attribute the fault to condensate blockage.

Mind you - 30% of the faults are caused by faulty sensors!!!
 
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There are sensors in the heat exchanger that are specific to this fault.
They detect the condensate level in the heat exchanger and hence attribute the fault to condensate blockage.

Mind you - 30% of the faults are caused by faulty sensors!!!
Thanks oz-plumber, I did wonder if perhaps sensor failure could cause the same effect (boiler shutdown/lockout)
[automerge]1587389998[/automerge]
What boiler are we talking about?
Worcester Bosch Greenstar 18Ri.
 
There’s no sensor that I’ve seen they just rely on flame supervision, when the heat ex is full of condensate (or rainwater in some cases) it won’t light and goes into lock out. You can hear the water sloshing around when it’s half full and that’s generally when you get the phone call “my boiler is making a right racket”
Thanks oz-plumber, I did wonder if perhaps sensor failure could cause the same effect (boiler shutdown/lockout)
[automerge]1587389998[/automerge]

Worcester Bosch Greenstar 18Ri.
 
What does? Are you saying an increase in fan pressure correlates to a blocked discharge? That would make sense

how the boiler senses the condy is blocked water will rise back into the hex blocking the flue so the ap switch senses this which in turn turns the boiler off / fault
 
how the boiler senses the condy is blocked water will rise back into the hex blocking the flue so the ap switch senses this which in turn turns the boiler off / fault

I'm with you, thanks. You would of course have the same fault should the flue become blocked
 
Don’t under any circumstances attempt to by pass the sensor.

To avoid such intervention, most boiler control logic sequences will initially test the APS to be open before fan start up, only firing once the fan has started and subsequently proved the APS closed.

Never override or attempt to override a safety control sequence.

In my business it is a summary dismissal offence.
 
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Don’t under any circumstances attempt to by pass the sensor.

To avoid such intervention, most boiler control logic sequences will initially test the APS to be open before fan start up, only firing once the fan has started and subsequently proved the APS closed.

Never override or attempt to override a safety control sequence.

In my business it is a summary dismissal offence.

Agreed Brambles. We had this conversation some time ago 👍
 
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