Combi fan cycles every time even when cold water is used?

[azillio]

I hope someone may be able to help please..

I'm not sure I've only just noticed this, but of recent our Worcesester (non condensing) boiler does a short fan cycle each time any water is used - either hot or cold. I'm pretty sure that it hasn't done that before?

The fan cycles when the boiler is idle, which is normal, but how frequently might be normal? Will the hot weather have made it more frequent?

I began noticing it while the flat below was being fully re-plumbed and switching the mains on and of frequently, and I could feel the boiler clunk a little from the change of water pressure when the water was going on and off. And our boiler fan seemed to cycle a lot while they were doing the work downstairs. This may have been a coincidence?

If it's any help, (again I may be imagining it, but I don't think so), I find that when I turn a (cold) tap on and off, the boiler seems to make a slight 'slooshing' 'woosh' sound (a water pressure sound) when the tap goes to 'off'. Nothing drastic, but it seems new..

Is any of this quite normal - I've become a little paranoid since all of the work was going on downstairs..

Many thanks.

 

[Agile]

Its usually caused by a minor piping fault.

Often called a dead leg where air accumulates but can have other causes too.

Usually easy to prevent with a carefully located non return valve.

Other boiler start ups could be hot water preheat.

Tony

 

[azillio]

OK, thanks - I'll search a little more and see what I can come up with...