baxi bahama gas supply problem???

[caerphillymotcentre]

baxi bahama 100 (honeywell) been running fine since changing a flow switch 12mths ago. now it doesnt seem to want to fire. the ignition is working but something is stopping the gas supply?
i firstly turned the gas supply off on the mains then turn boiler on first then turned gas on and it fired and ran fine all night. i called swalec and they sent an engineer to check mains box who told me it was the pressure relief valve on top of the boiler, but this seems to be working fine and also doesnt seem to control any electrical circuits?
i dole checked the hot water flow switch and it did seem to make any difference when unplugging it.
i shorted the flow switch connection and the the boiler clicked into life and worked all night again.
does this sound like the flow switch or something else? could the system need to be flushed out because it is causing flow switches to stick?
not sure which was to go?

any help would be great
cheers

 

[Agile]

This all seems very confusion particularly electricians coming to look at gas boilers!

The system flow switch will prevent the gas being turned on.

As you have already discovered the flow switches regularly get stuck or jammed on your model.

For a start you could suspect the flow SW and disconnect it/short out the inlet contacts on test ( only ).

Tony

 

[caerphillymotcentre]

ok i will drain system and remove flow switch tomorrow and check contacts and see if anything is effecting its operation.
cheers

 

[Agile]

Far better to test it electrically before you start to disconnect anything!

Tony

 

[caerphillymotcentre]

will bring multimeter home tomorrow

 

[baxpoti]

Whilst the primary flow switch is removed, thoroughly clean the barrel it sits in, so that is smooth to touch, an old toothbrush cut in half will do the trick!

 

[Agile]

Even better trick is to heat up the shaft of the toothbrush and bend it 90° so you can operate it more conveniently.

Tony

 

[caerphillymotcentre]

i've replaced the flow switch and it seemed clean on the hole??
there is something else stopping the gas flow.... it will work now and again (only when u dont want it to) what else can i check? it cant be anything broken as it works now and again

 

[caerphillymotcentre]

i couldnt face another shower so i turned the gas off at the main then turned the boiler on 3 times, turning it off before the 'no flame' orange light came on. i then turned mains back on and then the boiler and its working again??
no sure if it will work tomorrow tho? wierd

 

[baxpoti]

the 'no flame' orange light came on

Take it you mean the red flame failure light (right hand side) if so, you need to have the gas valve pressures checked, high and low. If these are correct a new gas valve is likely.