Baxi Brazilia puzzle

Tim+ brought next idea :

Or it could be the thermocouple going a touch low in output, or poorly aligned.

Tim

The manual at

Maybe newer ones have a thermocouple as a flame failure device, and olderones don't?

Owain

The Wolsey site seems broken and for me the manual there is for a completely different appliance.

However:

Mine is about 30 years old and has no thermocouple. It lights instantly with no need to hold the knob in. Nor does the gas shut off if the flame fails.

Tim

Mine predates that. That was just the first similar model I found on line. My mistake. Mine *definitely* has no thermocouple.

Tim

As an alternative to a thermocouple to sense the flame, they can use an electronic system, with a probe in the flame.

One of the attractions of that sort of heater is they don't need any electricity, which makes them useful in caravans and site huts etc.

Owain

Is there a metal gauze filter associated with the burner that has been clogged with dust and is restricting air flow? Again, the wrong instruction manual shows a burner gauze which will be an easily blocked fine metal mesh.

Pages 12 and 14 of

It?s actually a pretty coarse mesh and it wasn?t blocked. If there was any blockage then I would expect yellow tips to the flames or soot formation (of which there was none).

For the doubting Thomas?s here,

The burner was clean and whilst there were a few dead insects in the bottom of the fresh air inlet, there was nothing significant.

The mystery remains. I?ve put it together again and it seems to be behaving but until I leave it running for some time I can?t be sure.

Tim

aka 'lint arrester'. The name game me visions of being something complicated - when I finally realised what it actually was, and how crude a 'device', I had to laugh...

Tim+ has brought this to us :

Another possibility, is that the flame is simply lifting off the burner, due to too much air flow draft. Once it is lifted high enough, it can go out.

It?s never gone out before. Hard to see why the airflow should be higher than normal when it?s a passive balanced flue setup.

Tim

Wind, external drafts. Has anything changed outside by the flue?

Nope, no changes to the flue. Of course wind is a variable and it?s just possible gusty wind was responsible. Just odd that it?s never happened before. Must be global warming. ;-)

Tim

A change in local gas pressure (too high or low) could do it. You would need to test at the fire with a manometer.

Possible I suppose but none of our appliances have changed. Vaguely possible that our new gas meter?s regulator might be set a bit low but I dare say these things are checked before leaving the factory.

I opened up the combustion chamber but apart from a tiny bit of rust (nowhere near the burner) there was nothing to see. I did pull out a ball of cobweb from the air inlet but as I had to do this ?blind?, it?s possible that there was quite a lot of it.

Anyhow, it?s not gone out since so I think I?ll service it again in another

Tim

A heating engineer charged me £300+VAT to sort out my non firing boiler., he changed the flame sensor, he changed the oil pump. He changed the motor capacitor, He would have changed the blower motor too, but fortunately he didn't have a spare in his van.

But I reflected that, in the end, having all that lot in a 20 year old boiler that had never been serviced more than once, replaced, was actually pretty good value ...

Flame sensor and oil pump had gone - oil pump because it ran continuously with no flame - and had blown its seals. And caps don't last forever, so no biggie. His 'motor may not last after being soaked in heating oil;' proved incorrect. It's doing fine.

In fact the same goes for a lot of kit. Its cheaper to fix when it breaks than service regularly.

And often its cheaper to replace than to fix when it breaks.