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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> CH and HW failure on Baxi 105e https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1236026508 Message started by andy67 on Mar 2^nd, 2009, 8:41pm

Title: CH and HW failure on Baxi 105e
Post by andy67 on Mar 2^nd, 2009, 8:41pm

hi,a few weeks ago my hot water started playing up,every now and again it failed to give hot water,(although the heating was working fine),then this morning i woke up and the heating had failed to come on too,after several attempts to get it going it s just not working,so now ive got no hot water or heating.The red flashing light on the display panel is suggesting fan/flue problem,but i saw on another thread that it could possibly be a PCB problem.if any body can help it will be very appreciated.

Title: Re: CH and HW failure on Baxi 105e
Post by Headrush on Mar 3^rd, 2009, 5:09pm

That was me that had that problem before. The first thing to check is that the fan is actually running, then check the air pressure switch. You can do this with a multimeter and check the switch terminals are actually switching live or not. I seem to remember it was 24v should be present at each terminal when the switch activates. If this is true, check that the voltage is getting all the way back to the PCB from the switch by tracing the wires back. If this is true, check the ignition is sparking. If this is true, then you might have a nasty problem :-/

Also try removing the hose or hoses (depending on the age of the boiler, the later switches only have 1 hose) from the switch and check you can blow freely through them and that they have a good tight fit. It's also possible the fan is running at reduced speed, try releasing the burner cover screws slightly and you should hear a healthy sucking noise around the rim.

It could also be something a simple as a lack of pressure in the system, but then the pump warning light would be flashing. That's if the warning lights are not lying to you :-?

There's a copy of the boiler manual online with a fault diagnosis, for what it's worth, here:

http://www.partsarena.com/baxi/System/DATA/Dx/DS1/installation/2288/I05-2288/I05-2288.htm#zfaultfinding

I hope it helps, good luck.

A new PCB is over £100 at trade, so it's best to eliminate all other possibilities first.

Title: Re: CH and HW failure on Baxi 105e
Post by andy67 on Mar 3^rd, 2009, 5:53pm

thankyou very much for your time ,i will try all that you have suggested and will let you know how i get on.

Title: Re: CH and HW failure on Baxi 105e
Post by Twobarrows on Mar 6^th, 2009, 9:04pm

.......and going by the number of posts on here for Baxi 105 problems, if you've got to fork out 100 sovs for a poxing little PCB, you might as well got the boiler replaced with a reliable one!

Title: Re: CH and HW failure on Baxi 105e
Post by andy67 on Mar 7^th, 2009, 10:47am

was thinking along them lines myself!! Well,ive changed the pcb and the pressure switch and its still not working,now ive got a flame failure light flashing and the fan is not working at all,when i had the pcb and switch changed it did fire up then after a few seconds it went off again,tempted to change the fan now but where do you stop throwing good money after bad.any ideas anyone?

Title: Re: CH and HW failure on Baxi 105e
Post by Headrush on Mar 7^th, 2009, 11:51am

Have a look here before buying anything else, I guess it's a bit late now you already payed for some spares. This company specialises in reconditioned boiler spares at around half price of new and guarenteed for 1 year.

http://www.adlinkuk.co.uk/products/Boiler+Spares/?page=4

Title: Re: CH and HW failure on Baxi 105e
Post by greg on Mar 8^th, 2009, 10:10am

I would suggest that you get an engineer in, as it seems as though you are changing parts, perhaps unnessecarily, rather than diagnosing a fault

Title: Re: CH and HW failure on Baxi 105e
Post by Twobarrows on Mar 9^th, 2009, 12:44am

wrote on Mar 8^th, 2009, 10:10am:

I would suggest that you get an engineer in, as it seems as though you are changing parts, perhaps unnessecarily, rather than diagnosing a fault

Oh we diagnosed the fault, it's a baxi

Title: Re: CH and HW failure on Baxi 105e
Post by greg on Mar 11^th, 2009, 6:00pm

wrote on Mar 9^th, 2009, 12:44am:

Oh we diagnosed the fault, it's a baxi

;D ;D