Alpha 240X

[sunnyade]

Hi

My Alpha 240X is playing up. When you first turn on a HW tap, the boiler will ignite and heat the water. After a couple of minutes the gas goes off, and won't go back on until the water cools and you shut off the tap. Much the same with the Central heating.

I recently changed the thermocouple and made sure interrupter was properly seated.

I'm thinking the overheat thermostat, anything else I should be looking at?

Thanks

 

[gas4you]

Could be a partially blocked heat exchanger

 

[Gasguru]

Could be an intermittant flow thermister (on the left) going open circuit at a particular temperature. As soon as the burner cuts out turn off the boiler and check the sensor resistance.

 

[superdupergasman]

Could be an intermittant flow thermister (on the left) going open circuit at a particular temperature. As soon as the burner cuts out turn off the boiler and check the sensor resistance.

Sounds good to me!!

 

[Agile]

Could be an intermittant flow thermister (on the left) going open circuit at a particular temperature. As soon as the burner cuts out turn off the boiler and check the sensor resistance.

That can be difficult to do.

If you had the technical competence its better to monitor the current thought the sensor and see if it stops at the cut off point.

However, I would be seriously suspecting the pcb after checking all the other periferals were OK.

Tony

 

[sunnyade]

Hi

Thanks for the great responses.

Is the intermittent flow thermistor the same as the Primary temp. sensor? About 5 inches below the overheat stat?

Regards

Update

Turns out it was the primary heat exchanger - as per the 1st response. Many thanks all

Sunny