Baxi 105e, no CH, uuurrgh...

[dar2008]

Boiler set to permanently on,

Thermostat turned up so that it clicks to fire up the boiler... but boiler isn't firing up

DHW is working fine, on demand.

No fault lights flashing.

Pressure is ok at 1bar.

All was working fine this morning, but now house is cold


Could the diverter value be stuck? All suggestions gratefully received.

 

[craig51]

Most likely the dhw diaphram. Easy enough to replace if you know how.

To confirm, you should be able to see the rod be pushed out when a demand is made for hot water, which in turns makes a switch. When these get worn/torn, the pressure diferrential is lower acting on the diaphram, therefore not pushing the rod out!

Or, it could be fine, the switch is knackered etc etc

 

[misterdubya]

Most likely the dhw diaphram. Easy enough to replace if you know how.

To confirm, you should be able to see the rod be pushed out when a demand is made for hot water, which in turns makes a switch. When these get worn/torn, the pressure diferrential is lower acting on the diaphram, therefore not pushing the rod out!

Or, it could be fine, the switch is knackered etc etc

Am I missing something here? Isnt the hot water working ok?

Mr. W.

 

[muggles]

OP, please can you confirm whether this is a Baxi 105E or a Baxi 105E Instant They're different boilers, so this is important!

 

[dar2008]

Yes, HW is working ok, but no CH. The CH light doesn't light up even though the thermostat is asking for demand - have actually replaced thermostat with link wire to prove thermostat wasn't at fault.

Stuck for ideas...

 

[onlyfitidealboilers]

there most likely no demand from external controls ie no voltage on the switch live back

have you a multi meter if not time to call a pro

 

[craig51]

DOh!!!!!

My bad. Got hung up on an exact same appliance i was at 5 days ago!

 

[dar2008]

OP, please can you confirm whether this is a Baxi 105E or a Baxi 105E Instant They're different boilers, so this is important!

This is the 105e Instant.

There is definitely demand from the external controls.

At a loss for where to go with it from here. I'm comfortable working with plumbing and electrics but think I'll maybe need to call someone out if no one has any other ideas.

So second question... where can I find a good plumber? I'm based in SE London / Kent borders.

 

[nogoodatfaultfinding]

OP, please can you confirm whether this is a Baxi 105E or a Baxi 105E Instant They're different boilers, so this is important!

This is the 105e Instant.

There is definitely demand from the external controls.

At a loss for where to go with it from here. I'm comfortable working with plumbing and electrics but think I'll maybe need to call someone out if no one has any other ideas.

So second question... where can I find a good plumber? I'm based in SE London / Kent borders.

Remove the external controls on the pcb and put in a link to let us know what happens then please.

 

[dar2008]

OP, please can you confirm whether this is a Baxi 105E or a Baxi 105E Instant They're different boilers, so this is important!

This is the 105e Instant.

There is definitely demand from the external controls.

At a loss for where to go with it from here. I'm comfortable working with plumbing and electrics but think I'll maybe need to call someone out if no one has any other ideas.

So second question... where can I find a good plumber? I'm based in SE London / Kent borders.

Remove the external controls on the pcb and put in a link to let us know what happens then please.

With the link in place it's exactly the same

 

[gavinda]

had the same fault on one of these last year. iirc the thermostat is 'first' in line on demand, and then the timeswitch. bridge out, both the thermostat AND the timeswitch and see what happens.

took 3 phonecalls to poxi before the 'tech' help actually listened to my readings.

 

[Baxmax]

C.H Thermistor

 

[boilerdoktor]

baxmax can you link that stat to prove it's that or not pal?

 

[Baxmax]

No its an negative temperature coefficiancy stat,However as it is late you could swap the connectors dhw to ch .....ch to dhw to prove it.

 

[dar2008]

No its an negative temperature coefficiancy stat,However as it is late you could swap the connectors dhw to ch .....ch to dhw to prove it.

How confident are you that it's the CH Thermistor? And by this do you mean the CH temperature sensor?