Kettling boiler query

[tom patton]

Just arrived back from hols to be told "the boiler is making funny noises".its a Mexico C60 type with the usual boiler adjustable thermostat controlling the gas valve-recently replaced. There is no air in the system-atmopheric type-not closed system. When the system calls for heat the boiler emits fairly impressive noises and the expansion pipe gets mighty hot after a few minutes. Could the boiler thermostat be open circuit or does it not pass current when it fails. All suggestions will be appreciated.

[Doctor Evil]

If all checks out then use "Fernox" decaler. Flush out properly after and use inhibitor. Replace inhibitor every 3 to 4 years.

[Christian McArdle]

A failed pump is a very common cause of this. Other pipe blockages, perhaps from failed zone valves are another, but less likely, cause.

Christian.

[Ed Sirett]

I'd go for the pump, it might only be stuck as it lay unused while you were away. However it is probably on its way out.

The end of the pump motor has either a black plastic knob or a chromed plug with a large slot in it.

In both cases unscrew and then use the knob to unjam the pump or the newly exposed screw slot under the plug.

expect a little (filthy) water to come out.