how to replace boiler thermsostat on Ideal Boiler Moder 5oN

[pole91]

I have a 20yr old Ideal Gas c/h boiler model 50N which takes ages to switch on again after top temperature reached. Thought I'd replace the boiler thermostat. Bit worried by the boiler end of it. There's a fixing pin across the opening the probe disappears into. Do I simply remove this pin and the probe comes out? Or do I have remove the inner sleeve (nut?).

(Haven't bought the new thermostat, not yet located a web site with my model on it - the BGC no is 41/409/13 )

 

[Agile]

DONT remove the nut! Only the pin and it should slide out! Best to add some heat transfer paste if you replace it in your case.

But before you change it, you should measure the boiler flow temperature. The new hysteresis is usually about 6° but this can get larger as it ages.

However the problem could be associated with the pump and flow so measuring the temperature is advisable first!

Tony

 

[pole91]

Tony - many thanks for that.

You could be right about the flow rate. The pump was replaced only a few years ago but the problem is worse with only the c/h circuit (micro-bore) on by itself. If I add in the h/w it improves a little (though still not satisfactory imo).

The thermostat is the easier job but from what you say it may be a waste of money!

Murray