baxi combi 80HE plus

[mobylec]

dhw ok but no heating,have changed motor head on valve but no difference,flow chart diagrams do not correspond to terminals on pcb,but indicates pcb u/s.have also found dhw/ch valve seized.any one have any other ideas boiler only 2 years old.
mobylec

 

[LUNAT]

HI



sorry need more details
and which motor head you replaced?

 

[mobylec]

hi have repaced dhw/ch diverter motor head(honeywell)
mobylec

 

[mobylec]

it appears that diverter seized causing motor head to stall and possibly damage pcb.
as i said the fault diagram does not correspond to connections on boiler pcb and so voltage readings are inconclusive when compared to fault diagnosis in service manual.
mobylec

 

[ChrisR]

If you remove the said head you should feel the pin it pushes. If you push the pin hard it should spring up and down, I use a short 1/4" square drive extension to do it. A short pencil would do.

I vaguely remember that the voltages they tell you should be going to the motor, are wrong.

 

[Agile]

I have edited this out as I was referring to a different type of valve motor.

Tony

 

[mobylec]

i appreciate both your comments. have pushed valve head stem but is very tight and does'nt spring out so for some reason has seized i will need to replace.
but fact remains that the flow diagnostic for central heating and terminal designation does not correspond to the schematic diagram.on page 58 of servicing details the terminal diagram showing G with space to left (orange wire.) on boiler and schematic the space is 2nd terminal in to right.have 240v upto H so can only conclude that pcb is faulty.
mobylec

 

[baxpoti]

All you need is the
Valve body complete with gasket part No. 247310

If your competent you can just change the inner
Cartridge 3 Way Valve - Honeywell VCZZ6000 Part No. 241361

The latter will probably be jammed in and will break up on removal.