Ideal Classic FF340 - Fires up then stops, cold radiators to

[NickCurtis62]

Hello
Have a Classic FF340 which fires up both manually or via timer but shortly after it stops. A bit of ON/OFF on the switches get it running again but not for long. producing some hot water but the radiators remain cold.

If left on it will start up again, fire and light the boiler and stay on anywhere from two to ten minutes then will stop again. Never gets any better.

Any advice would be appreciated

 

[45yearsagasman]

A common fault is one of the three sensors has failed. This is easily checked and fixed by a Gassafe RGI but it is not for DIY repairs.

 

[NickCurtis62]

Checked the pump. It's very hot and cant hear or feel it running. Could it be that the system is sensing a faulty pump and shutting down?

 

[ianmcd]

The boiler is getting up to temp very quickly as your pump has seized, let the pump cool down and turn everything off, remove the bleed screw the large screw in the centre and below that is the shaft screw try and free it off with a screwdriver have a towel at hand as some water will come out when you remove the first screw head, if you can turn it freely put the bleed screw back in and try your heating

 

[keego]

Checked the pump. It's very hot and cant hear or feel it running. Could it be that the system is sensing a faulty pump and shutting down?

AFAIR there is no flow sensor on these boilers nor does it have pump over run, if you're checking the pump when the boiler is up to temp then it wont be running, make sure the burner is lit when you test the pump.
Also if your system is an S plan then the heating zone valve may be faulty in which case when the hot water is up to temp the HW valve will turn the boiler off even if you have the heating turned on.

 

[NickCurtis62]

Replacement pump on its way - seems to be the easiest starting point and does not involve any messing near the gas end of things. Will i need to drain the system or just turn off the two vales either side of the pump?