Pipes making a racket when boiler starts heating the water

fraggleKFC_2

yeah it's running ok, always get hot water

Canucklehead

fraggleKFC wrote: »

Drained and refilled whole system, problem still exists

10 minutes after the hot water starts heating there is banging in the pipes, specifically 2 radiators near the boiler. the radiators heat up slightly. I bleed the radiators till just water comes out, 10 minutes after the pipes banging if i bleed radiators again i get alot of air coming out. This is all with the heating off!

Also, whilst the water is heating, one time I went into the loft to the expansion tank. After the banging, the tank started to fill up with roasting hot water coming into the tank via the pipe at bottom of tank. Water level raised around 2 inches. 30 seconds later water level back to normal with water going back down the pipe it had just come up!

Anyone any idea whats going on there???

Thanks

I think you need to post photos of all the relevent parts.

Cylinder cupboard (and/or wherever the pump and pipework is)
Boiler (showing flow/return)

You seem to have moved the point at which it starts to get noisy by 10 minutes?!

Anything to do with your new bathroom? Did they fit a towel rail to work when there is a demand for hot water?



GSR

keystone

Canucklehead wrote: »

Did they fit a towel rail to work when there is a demand for hot water?

and if so has it got a TRV on it?

Alternatively was one taken out and not replaced?

Cheers

fraggleKFC_2

Fixed!

closed the bypass valve and the problem has dissapeared. seemingly having the valve open was allowing hot water from boiler to go to the cylinder along both the pipes, ie flow and return so it was working against itself.....