Alpha CB24 - wont fire up

[gasboy3]

Hi
Can anyone help?

Friend of a friend asked me to help her old grandmother who cant afford to get Alpha or BG out.
I dont have any experience of Alpha range at all, only qualified last year!

The boiler has no fault indicator flashing its on standby, (B flashing every secs)
On demand for DHW only o CH as well the pump operates but the boiler does not fire up
I replaced the diverter valve and flow switch as the flow switch fell apart when i took out and the diverter valve was so corroded.
Did a resistance test on the Primary temp sensor and DHW temp sensor both within range when cold although when measuring on the PCB with pump running
reading -161.9 om ^ is this normal?

Any ideas?

 

[ianmcd]

you cant test for resistance of the NTC thermistors while they are connected to the pcb as you will get false readings, the rest of the tests you need to carry out require proof that you are indeed gas safe registered so I would recommend you join the registerd engineers forum on here and someone will help you out

 

[ianmcd]

my apologies I agree , even though the poster claims to be gas safe registerd i have no proof of this and anyone can read so I have asked the moderator to remove

 

[Agile]

Thats odd, I thought that I had replied to that posting too.

Regardless of whether the poster is Gas Safe reg or not we still cannot give advice on gas matters because anyone can read this forum.

Gas reg engineers can join the Combustion chamber area and ask about gas matters there.

 

[gasboy3]

Sorted!

Replaced flame sensing electrode, works fine now

Many Thanks

 

[Agile]

That would be a fairly unusual fault on that model if there is continuity between tip and PCB.

Tony