baxi 105e sticking in HW mode

[karl12]

Hi Guys

Hope you can help me.
Got a baxi 105e combi. When I have been in shower the boiler is sticking
in hot water mode and not switching to central heating. I then have turn
off boiler and run hot water tap to get rid of hot water in boiler and allow
boiler to cool down. After doing this boiler runs ok until I next go in
shower. Had both HW and CH sensors changed. Any Ideas what is wrong.

 

[Paul Barker]

There is a microswitch on the front of the diverter valve which internally where you can't see the contact is sticking together. As it is a molded leed I would be testing the terminal on the pcb. It is usually a three leed switch with a C and two other connections one switched to the C when switch not pushed in and one when it is pushed in. So with a ohmeter on beep operate switch and see if from C to each of the other makes a breaks as it should consistently. Not just sometimes but 20 times without a failure to prove such a component.

In this failure mode when no hot tap running central heating will get up to about 95 degrees until ohstat kicks in, rest a few seconds and go again. short cycle at very high temperatures. Feel warmth of rads from 5 ft away.

Not a good way to leave it.

 

[ollski]

Yep they stick on alot, they are a pain but a nice easy job.

 

[karl12]

ok will check it out. Thanks guys

 

[karl12]

Hi again.
Does anyone know the part number for the micro switch

 

[blackpoolboilerspares]

You'll fine one here

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=200259278924&ssPageName=STRK:MESE:IT

 

[karl12]

cheers