Oil fired boiler overheating and shutting down

[Isonyme]

[Trianco Eurostar]. We recently had the oil pump replaced on our central heating boiler and was told it may cause the motor to fail. The boiler now has 3-4 attempts to fire-up, and does each time, but the water is very hot and it seems to be shutting down after making a "kettling noise". Do you think a new motor will fix the problem or do we have to have the system cleaned at great expense.
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[mysteryman]

Check your water circulation pump. It sounds like a lack of circ. Is the system full of water?

 

[Isonyme]

Circulating pump is working and have checked various rads and no air is present.

 

[Boilerman2]

Was the new oil pump set up with a oil pressure gauge? this is essential sounds like the boiler may be overfiring (too much oil)

 

[Burnerman]

Its a bit of a curious statement, that 'having a new pump fitted could cause the motor to fail'.....
Never mind. If the boiler is overheating the water then either its overfiring or the thermostats are set too high - or the circulating pump can't disperse the heated water.
Excess soot causes high flue temperatures but not to this extent.
John

 

[Isonyme]

Was the new oil pump set up with a oil pressure gauge? this is essential sounds like the boiler may be overfiring (too much oil)

The pump was replaced by a qualified engineer so I would hope it was set-up correctly. You just have to put your faith in them when I know nothing about this kind of thing.

 

[Isonyme]

Its a bit of a curious statement, that 'having a new pump fitted could cause the motor to fail'.....
Never mind. If the boiler is overheating the water then either its overfiring or the thermostats are set too high - or the circulating pump can't disperse the heated water.
Excess soot causes high flue temperatures but not to this extent.
John

I think what the engineer was meaning was the "new" part may cause the "old" part to fail. We are in a "hard water" area so do get a lot of limescale build up in the kettle. Could this be the case in the heating pipes, therefore causing the water to flow slower and hotter away from the boiler. It is a gravity fed boiler and during the summer we don't have the circulating pump running, it only heats the water.

 

[Kev F]

Limescale doesn't count, the motor will be on the burner, quite often the pump or motor burns out and takes the other with it eventually

 

[Burnerman]

Still a bit of confusion.....you said you had a new oil pump fitted - thats just fine, so long as the pressure was set to recommendations - but this has no effect on the water circulation which has a pump of its own.
Having said that, the heat exchanger in the boiler could well be heavily scaled - its impossible to tell from here.
You could try increasing the water pump speed (usually switchable 1 to 3) and see if this reduces the kettling.
John

 

[Isonyme]

Many thanks for all your advice.