worcester 28cdi pcb or gas valve?

[terrierman1983]

worcester bosch 28 cdi rsf. it ignites full burner on but carries on igniting then goes to burner lockout.
i fitted new flame sensor and checked continuity of the cable to the multi plug.
how can i test if it is gas valve or pcb? or is it something else?

 

[dcawkwell]

Won't be the gas valve as you have a flame.

Probably not the PCB either.

Worcesters seem to have a mind of their own though. Probably something completely unrelated.

 

[terrierman1983]

before it got to this stage it was working apart from it was constantly randomly igniting even though it was burning.

 

[dcawkwell]

Burner will shutdown if overheating. Perhaps faulty thermistor/connection.

 

[terrierman1983]

it does it straight from stone cold now though, makes no difference if heating or water either

 

[dcawkwell]

Air pressure switch / tubing related possibly.

 

[terrierman1983]

im think that if it gets to igniting the pressure switch is working.

 

[45yearsagasman]

If it keeps sparking then it is not sensing the flame and will go to lockout.
If you are gassafe registered then post on the CC. Possibly a gas related fault so get a pro to check it out. You should not be attempting this work and we should not be giving you all this encouragement.

 

[terrierman1983]

yes i agree with what you are saying but if there are any electrical tests i can do to try and determin if its pcb then i will have a go myself if its defo the gas then i can get somone in.

 

[scatmanjohn]

yes i agree with what you are saying but if there are any electrical tests i can do to try and determin if its pcb then i will have a go myself if its defo the gas then i can get somone in.

But you have already been dabbling inside the combustion chamber.

You now need a RGI to check it.

 

[misterdubya]

Which old Worcester has the Pressure Switch outside of the CC? It's irrelevent to the topic, but Agile posted it a while back, and I cannot remember

 

[45yearsagasman]

The old 24 and 28 cdi had the APS behind the control panel and I think this is the model under discussion.

 

[holty]

Which old Worcester has the Pressure Switch outside of the CC? It's irrelevent to the topic, but Agile posted it a while back, and I cannot remember icon_redface.gif

wb 240 rsf

 

[bengasman]

.. if there are any electrical tests i can do to try and determin if its pcb

Pcb in itself can't be tested, only the bits that are connected to it like switches, thermistors etc.
Solving this kind of fault is not in the diy area.