Hello I've just seen your posts whilst trying to come up with a solution to my in-laws boiler problem, it sounds exactly what is happening to their boiler! Did anyone get to the bottom of this in the end? I've replaced the temperature probe in the hope it was that which kept turning the heating on constant but it's still firing up 
The pin comes out when we turn the hot tap on and retracts when we turn the tap off, the boiler remains lit at all times. I tapped the microswitch a couple of times and the boiler went off for a couple of minutes and the came back on again. I don't know if we should try replacing the micro switch or the diaphragm, their boiler is an Ariston EuroCombi which approx 8-10 years old. Apparently the diaphragm may have been replaced about 3years ago.
Any suggestions or useful advice would be much appreciated!
Many thanks
The pin comes out when we turn the hot tap on and retracts when we turn the tap off, the boiler remains lit at all times. I tapped the microswitch a couple of times and the boiler went off for a couple of minutes and the came back on again. I don't know if we should try replacing the micro switch or the diaphragm, their boiler is an Ariston EuroCombi which approx 8-10 years old. Apparently the diaphragm may have been replaced about 3years ago.
Any suggestions or useful advice would be much appreciated!
Many thanks
