Niosey Central Heating

[Peter Hill]

Can you help? My central heating suffers from major noise from start up until the valve opens to let hot water thro' to the heating and then it settles down.

It seem to take for ever may be half an hour for the valve to open from start up. Is it a valve problem or is it the controller not operating correctly. The system is a standard balanced flue boiler and y plan valve arrangement. The controller is an old Randall type?

Any help would be appreciated?

 

[JohnD]

What sort of noise? Banging, whirring, clonking, gurling, fizzing, ticking?

 

[Peter Hill]

Banging in the boiler and you get some discharge up the feed and vent. It seems that the water is very hot but the valve is not opening to allow water thro' the heating circuit. As soon as the valve opens to heating it all begins to sound normal.

 

[JohnD]

mmmmmm. What brand/model of boiler? Do you mean that if you feel the three pipes at the electric valve, they are all cold until the CH opens, and then you feel the CH supply get hot? Does the pump appear to be running all the time, and does it feel hot?

Does it seem to be supplying water to the cylinder while it is banging and bubbling?

I gather this is the type where you have a small feed and expansion tank in the loft, and that hot water is being vented into it, is it coming up through the overhanging vent pipe, and is it very hot (near boiling) when it comes out?

 

[Peter Hill]

The boiler is a Baxi Solo, and it is a conventional cylinder, three way valve and feed & expansion tanks. The pipes are hot to the heating circuit after the valve this may be just convection and i think water is feeding the cylinder but i am only guessing this.
I do hear hear water venting to the f&e tank occasionally during the initial start up. This may be 25/30 mins after switch on when the water is red hot.

The pump is definatley running. Changing the speed does improve this a little, but the noise of the pump keeps you awake.

Hope this makes sense.