Boiler cutting out when heating water.

[worz]

Hi, I have noticed that when the hot water is heating the boiler is cutting in and out quite often. I am guessing there is air in the hot water heating loop?
It is a gravity fed system with 2 valves. The Heating is working fine.
What can i do to rectify this?

Cheers

 

[JohnD]

you could tell us what boiler you have, and the colour of your hot-water cylinder.

When you bleed the highest radiator in the house, does clean water squirt out forcefully, without dying away?

 

[Agile]

It is most likely that the boiler is an old and non modulating type and it is grossly over powered for the heat absorption of the cylinder coil.

So as it cannot modulate the power down all it can do is to turn off!

 

[worz]

Sorry for the delay. The Boiler is an old ideal mexico 2 and the hot water cylinder is a weird green colour. The top rad when bled does produce a strong flow of clean water. I filled half a jug!

Agile, why would this have changed, as they have worked in the past.

 

[Agile]

The boiler power is probably at least 15 kW and the nice green cylinder absorption perhaps only 6-9 kW so the boiler will have to cycle.

Perhaps you have not noticed the cycle time before?

Perhaps the boiler has been serviced and power increased?

Perhaps there is a blocked feed pipe to the system?

If it really bothers you then you will probably need an engineer to come and examine it. But he may well find that it is all operating correctly.

When was the boiler last properly serviced?

Tony

 

[fezster]

Sorry for the delay. The Boiler is an old ideal mexico 2 and the hot water cylinder is a weird green colour. The top rad when bled does produce a strong flow of clean water. I filled half a jug!

Agile, why would this have changed, as they have worked in the past.

Check the cylinder stat too. It should be approx 60 degrees. The boiler should be set higher than this, otherwise it'll cycle as the cylinder reaches max temp.