Ideal Classic ff2 100 overheating

[Jonny CHEETHAM]

Hi all. I have an Ideal Classic FF2 100 with a sealed system and a megaflow. Twenty years old, and serviced regularly. The problem is that once every few hours the boiler runs very hot and cuts out on the overheat thermostat. It seems to be ignoring the temperature control knob - it doesn't cut out even when the knob is right down. The plumber is saying it needs a new control board, but I wonder if it's more likely to be the knob / variable resistor, or the thermometer in the heat exchanger. After switching off for 30 mins (or it being killed by the overheat thermostat), it comes back on fine and operates as expect for a few hours, then starts to get very hot again. The pump seems fine and everything heats up quickly when it's on.

 

[Last Plumber]

I think (could be wrong) that the control box on that boiler comes with associated parts. e.g. pot, board, stat etc.
Surely he/she has tested the function of the boiler to arrive at the conclusion they did?

 

[Jonny CHEETHAM]

I think (could be wrong) that the control box on that boiler comes with associated parts. e.g. pot, board, stat etc.
Surely he/she has tested the function of the boiler to arrive at the conclusion they did?

Thanks for the reply. It's been a telephone consultation so far. He's saying he's sure it's the board. I'd rather he came to check, but that's an additional call out fee. Is there any obvious way to work out which bit's causing the problem?

 

[Last Plumber]

Thanks for the reply. It's been a telephone consultation so far. He's saying he's sure it's the board. I'd rather he came to check, but that's an additional call out fee. Is there any obvious way to work out which bit's causing the problem?

Not via internet or phone. A pot can be tested fairly easily and so can the sensor or stat normally. However, your fault does sound a bit intermittent or erratic and that could be caused by any faulty component on that circuit.

The choice is yours at the end of the day, we all work our own way. I would want to visit site and test things out to determine whether a part was required and which one.

I suppose you either trust his judgment and go for it or ask him to test it first and risk paying more.
A lot of boilers have recognized faults. Those who work on them regular will know them well. He may be very experienced and recognize the signs.

 

[Jonny CHEETHAM]

Not via internet or phone. A pot can be tested fairly easily and so can the sensor or stat normally. However, your fault does sound a bit intermittent or erratic and that could be caused by any faulty component on that circuit.

The choice is yours at the end of the day, we all work our own way. I would want to visit site and test things out to determine whether a part was required and which one.

I suppose you either trust his judgment and go for it or ask him to test it first and risk paying more.
A lot of boilers have recognized faults. Those who work on them regular will know them well. He may be very experienced and recognize the signs.

I guess that's fair enough. Thanks for the response.