Venturi keeps melting

[Agile]

Since no cause was ever found for the venturi melting then my advice would be to have the boiler properly checked to see whats wrong to prevent it happening agiin.

Tony

 

[mowflow]

Well the venturi melted again this morning. I'm pretty sure it was dry firing that caused it as the water pressure was at 0. I'm not sure why it dropped after a week remaining at a steady level.

I'll be calling the guys that fitted my boiler 4 years ago first thing Monday as they maybe have more experience with this model. I'm not going to bother getting my friend round again as although he's a corgi registered engineer running his own company he clearly either can't be bothered looking for the fault that's causing this or he doesn't have a clue where to start.

I'll be making sure the engineers i get round next week check all the possible faults mentioned in this thread. Thanks again for all the feedback.

 

[Agile]

Since no cause was ever found for the venturi melting then my advice would be to have the boiler properly checked to see whats wrong to prevent it happening again.

Tony

Crystal ball "on the ball" again?

 

[mowflow]

Got another CORGI engineer out last week. He had no clue what the exact problem causing the venturi to melt was either. On his advice i called a Baxi engineer out which cost me a fortune but looks to have fixed the problem.

The Baxi engineer said he had seen the problem once a couple of years back on the same boiler model, after a few calls to double check his memory served him correctly he replaced the PCB. It seems a failure in the PCB causes the boiler to fire up but not the fan, it's not easy to diagnose because it's not a complete failure so the fan works most of the time.

According to the Baxi engineer dry firing will not cause the venturi to melt, dry firing was my number 1 suspicion.

 

[Agile]

Under normal conditions the boiler will not proceed to fire up unless the fan is running AND has activated the air pressure switch ( APS ).

Its conceivable that the PCB could have a fault which proceeds to turn on the gas without needing the APS made.

Thats a very nasty fault from a safety point of view! ( Catching fire etc. )

Any boiler which dry fires runs the risk of melting the venturi. This acts as a safety device as the APS is then de energised and the boiler turned off.

Tony

 

[BingoBongo]

yep seen this on a few vokera flowmatics too.they completely melt the housing for the pressure switch which is unavailable(although the aps is) resulting in a dead boiler

 

[Agile]

Some of the early Vokers were a little naughty because they did not check that the APS was resting before the fan is started!

A nupty had shorted out the APS and the boiler was burning WITHOUT the fan running!

That was not as exciting as you might imagine because there was so little air available that it just ran with a wishy washy flame within the CC but NOT sitting down on the burner!

If I had more time I would recreate that and take a few photos as it was interesting to see!

Tony

 

[BingoBongo]

yep thats the fault that eventually melts the aps housing.burner on/fan not running

 

[baxpoti]

I think you will soon be on first name terms with your local Baxi eng

 

[mowflow]

I think you will soon be on first name terms with your local Baxi eng

I hope not. The price i paid included a years cover for fixing the fault so if it goes again i'll be straight on the phone. I'd rather not have the bother though.

 

[Gas2Air]

I think nickso deserves a round of applause for faulty PCB on this one. clap clap clap.

 

[nickso]

yep seen this on a few vokera flowmatics too.they completely melt the housing for the pressure switch which is unavailable(although the aps is) resulting in a dead boiler

there is a kit to replace the housing.

 

[nickso]

I think nickso deserves a round of applause for faulty PCB on this one. clap clap clap.

i'd like to thank my mum and dad, my tutor at gasman college and everyone at BG, except the ones i dont like which leaves about 5 people in reality.