Alpha CB24

[rob jefkins]

I have a customer complaining that her Alpha CB24 runs for about 20 secs and then cuts out. I'm not going round until the morning to look at it but I think I should firstly look at the overheat stat and the flame sensing electrode.
Anyone had this problem recently???

p.s. I'm going on a multimeter course shortly but until then I go by instruction booklet

cheers

 

[Puddle]

could be not sensing flame on burner after light up due to pcb fault or circulation problem

 

[MartinSC]

Might be a similar fault
My customer's alpha cbx runs for quite a long time then locks out,(continuous red light) . He hasn't been able to see any pattern to the lockouts. I went to look the boiler was locked out. Before re-setting it I checked the o/heat sensor and it was O.K. the thermistor was the correct resistance, there were no earth or polarity problems , the external controls worked fine. I reset the boiler and it ran lovely,
gas rate spot on, turned it on and off a few times .. O.K.
I'm thinking could it be possible for a fault to only occur when the heating gets up to full temperature?

 

[Mbear]

Remove primary sensor and inspect(top r/h of h/e iirc) if it's manky, replace it. Sounds similar to a fault I had a while back this boiler

 

[Billy Bob Bob]

could be detection or thermistor baxi 105 thermistors the same

 

[MartinSC]

Thanks I shall give that a go 🙂

I wanted to check the ignition lead on a cd32C
I went into my local spares shop and we tried a continuity test on my old one .. no continuity, it must be broken.
We did the same for a new one
What a surprise!
No continuity!
I wish I had had a bet on it.
That is strange, how does it work, I think there must be a capacitor in black sheath on the lead?