Baxi 105e no central heating

[gusmagicbus]

Hello,

I have a Baxi 105e which stopped working. I called out a plumber who advised me that the boiler needed a new PCB and Extractor Fan and it was a very common fault on these models. I bought the new items and fitted them. The pcb was slight different setup to the original, which I believe you can't get anymore. I bought this one http://www.ebay.co.uk/itm/131279675620?_trksid=p2060778.m2749.l2649&ssPageName=STRK:MEBIDX:IT

The hot water now works fine but the central heating does not switch on. I have checked that the room thermostat is closing the 240v circuit and it is. I have also checked that the black wires out of the timer switch continuity when the heating should be on and that seems fine too.

I'm not sure what to check from here? Can anyone help please? I guess the new board could be faulty...?

Thanks

 

[Boilerman2]

No one is going to advise you other than you need to get a Registered Gas Installer in working on gas appliances unregistered is unwise

 

[gigz]

Heads down, INCOMING.

 

[Agile]

No DIYer should ever be opening the combustion chamber where the fan is located.

So why did this "plumber" not fit the new parts?

Did you pay him to diagnose the fault?

Tony

 

[mcmoby69]

i think its the pcb too.

 

[sbgasman]

It sounds like the plumber might have worked out he was not getting the repair job ,and told the OP that boiler requires two expensive parts.

 

[gasright]

Could be the flux capacitor, common fault on the 105's.

But you need to be qualified to fit the part.

 

[mfarrow]

The old Siemens board had green solder resist and was very complicated. The later Honeywell boards had a clear/yellow solder resist and was a lot less cluttered with a central processor and a lot more reliable.

The fact the board was made in 2009 and is on eBay of all places rather should set alarm bells ringing.

The fan was probably fine, it's 230V and should be easy to test. It's only a core of iron and some copper wire - not a lot to go wrong except the bearings may wear after a dozen years or so.

If you're not getting any sign of life on heating call, not even a fault light, then something's fundamentally wrong with either a dry joint or dodgy componentry.