Availlant 242 keeps firing up

[rowing78]

Hi, I have an Availlant turbomax 242 boiler and for some reason it keeps firing itself up staying on for a couple of minutes and then back off even though the timer is off, at fist I thought maybe it was the cold weather but it has warmed up now so I would be surprised if its that.

It has been doing this for about a week now, since it has been doing it I have replaced the pressure relief valve as it was leaking, it fixed the leak but it still turns on and off. Any ideas of things to try?

 

[Agile]

Check the resistance of the temperature sensors at the PCB connector end with the boiler totally cold.

Where abouts is the boiler fitted in the building?

Tony

 

[rowing78]

I haven't been able to measure the resistance yet but have just noticed when it does come on the radiator light flickers around a little bit, also if you put a bit of pressure on the timer clock and turn it slightly it comes on. Does this mean I should look at replacing the timer?

The timer on my unit is an analogue clock with little nodules that you push in an out as and when you want the boiler to come on.

 

[Agile]

That additional information now suggests that the timer is at fault.

Many modern digital replacement will fit the old baseplate without changing the wiring.

Regardless the connections do need to be checked to ensure they are the same.

Tony