Boiler and Pump Noise

[eamonnk]

I recently fitted a new kitchen in our house which involved draining the central heating system to remove a heater situated under one of the base units. Since then the boiler is making a lot of bubbling sounds, and the pump in the airing cupboard sounds like a car alarm.

I have checked the cold water header tank and it is full and the valve works OK. I have also tried to clear any airlocks in the hot water system by forcing mains cold water into the system and opening a tap elsewhere in the house.

The radiators do work when I test the heating. I have bled all of them and they all heat up OK.

One thing I don't understand is why the draining the central heating system has had this effect on the hot water?

The system is over 20 years old and would probably benefit from a power flush. It was noisy due to sludge before I drained the system, but nothing like it is now.

Any ideas?

 

[seco services]

have you bled the pump ?
if your heating is working is the hw getting hot

 

[eamonnk]

The hot water gets hot OK - only problem is with the noises. Haven't bled the pump, how do I do this?

 

[seco services]

if your heating/hw is working ok then the pump is working.
unless the bearing is going on the pump. which will make a high pitch squeel.
try the pump on different speeds.
any air in the system will useally find its way out.
does the boiler keep running or shutting itself down due to overheating.

 

[eamonnk]

Thanks for your replies seco services.

The boiler does turn itself off when the pump noise starts up, though as I said it does eventually heat up the water and radiators. When the boiler is not firing, the pump still makes the same noise, I turn the power to the system off eventually to get rid of the noise and use the immersion heater instead. Generally the pump noise does not start immediately, but cranks up after 5 minutes or so.

I am not too familiar with the workings of the pump, how do I change the pump speed?

 

[seco services]

on the side near where the cable enter is a switch 1 2 3 usally set on about 2 try turning it on to 3
sounds like the pump is sticking their is a screw inthe centre of pump which you can remove and see if its rotating freely and not sticking.
just place a towel underneath when you remove screw.

 

[eamonnk]

Thanks for the info - I will try that tonight.