boiler on/off

[ian m]

I have a ideal classic ff 260 boiler that comes on for a minute then turns off for 30 seconds then lights up again for a minute.The boiler setting is on 6.If i turn the thermostat down on the boiler then this will switch the boiler off so i know that the stat is working as is the room stat.
Could this be a faulty sensor in the boiler?
I live in a house that is 3 years old and all the houses have the same boiler but no one seems to have the same problem as me
any ideas?

ian m

 

[ChrisR]

Does it get very hot in that 30 seconds - dud pump?

Could be a faulty sensor - worth a call to Ideal.

 

[ian m]

The rads do get hot.
I think it could be a sensor that is at fault.
I will phone Ideal to see if they can help

 

[ian m]

I have been on to Ideal and they think that it could be the stat in the boiler.Will i have to get a plumber to do this or is it a job i could do my self.What would be involved?

 

[BDL]

Ian the 3 things on the boiler that could cause this cycling on/off problem are:
thermister ( black lead from pcb to top left of heat exchanger)
Potentiometer ( from the back of the black knob on the front to the pcb)
Pcb- ( board 25c)

The only sure way to tell is to check the resistance of the thermister in conjunction with the temperature the boiler shuts off at.

A relatively easy task for any Heating engineer to do, I would steer clear from the change em' and see cowboys.

If you need any more info let me know- I have the resistances filed somewhere.

Best Regards.

 

[angelf]

what are the resistances then>

 

[bengasman]

don't these things have an anti-cycle that can be turned on or off?

 

[Agile]

As boilers are very reliable, my first check would be the flow and return temperatures of the boiler as this would indicate a faulty pump or blocked circuit.

Pump setting should be "2".

Next would be the power input to the boiler as if too high that would cause the same problem.

Tony