I may be missing obvious

[stewm]

The dreaded banging from heating pipes during the night, tried pump speed, bleeding rads all seams in order but banging continues....suggestion most welcome

 

[kay-jay]

Maybe loose pipes need clipping

Sent from my GT-I9100 using Tapatalk 2

 

[Mike Jackson]

Are you sure it's the heating pipes. Water hammer is common at night when the water pressure rises due to less use.

 

[hydrotherm]

Are the pipes running behind your headboard?

 

[mountainman]

Does the banging happen after a particular event eg toilet flushing?

Does the banging rise in pitch whilst getting quieter and eventually stopping?

Both these could indicate a dodgy ball valve.

 

[stewm]

Thanks for replies, keep going GT still reving up, most certainly heating pipes, all pipework is secure, headboard hardly used, no particular event causes disruption as all half asleep...keep going all ideas listened to cheers.

 

[jtsplumbing]

Are you in a house or flats ? it may not be your pipes that are the problem !

 

[snowhead]

Worn drive quadrant or motor gear on a 3 port / diverter valve.
It can cause the valve to slam shut.

 

[ManchesterGas]

Dodgy TRV/TRV's?

 

[zzzjim]

If on a timed programmer , make a note of time , and compare with where in cycle

As "snowhead" suggests do you have a cylinder ?

or" 500" any TRVs fitted ?

( a few more system details would help )

 

[stewm]

Hi apologise for lack of detail, but here goes yes a dhw cylinder but only two port valve on this as feed is t off main htg line, and yes trvs on rads but surely if anything these are going to open during the night, its also a floor standing boiler...hope this is a bit more info

 

[AWheating]

is the heating turned off throughout the night? make and model of boiler?

 

[zzzjim]

If system has come to a halt overnight , could pump be having a hard time getting things moving again . ( Sound travels well in a quiet house ! )

 

[stewm]

Hi the boiler is a Ideal Mexico HE30 and all has been left on overnight as was thinking along same lines, not a pressurised system fe tank.

 

[Bernie2]

One assumes that having a F & E tank its an oldish system? It is not necessarily so of course, but perhaps likely with the more widespread use of condensing combi's or ordinary combis now days. So being an older system, one assumes the banging has only just started?

It is possible the ball valve in the F&E is stuck and not filling the system for one common reason. Could be water hammer but possibly unlikely as there are usually very few loose jumper screw down valves with worn washers and loose jumpers on a central heating system one of the most common causes. And the ball valve in the F&E tank another common cause of water hammer is hardly likely to be opening and closing all the time unless there is a leak on the system.

I am of course assuming no pipework has been disturbed anywhere and it is all properly clipped? The usual common causes though are air in the system, no water and over heating.

Banging in a c/h water system has a few possible causes, but the simple explanation is that if you stop anything travelling you have to put as much energy into stopping it as it uses to travel.
Its one of Newtons Laws of Dynamics. The thing is if you run say a car into a wall it rebounds and water does the same but in rebounding, it rattles and bangs anything loose i.e pipes, worn washers or valves. Ball valves do the same sometimes just about anything that closes down a water stream that is travelling fast will do it. But a central heating system like the one you describe doesn't really have mains water pressures the most common for water hammer. So the banging is more likely to be air. That said it could also be kettling or boiling in the boiler causing explosions which can also be caused by boiler design, sludge in the system, TRV's, pump or port valves. The thing is it could be any of many things and possibly more than one thing. But check the F&E tank as it is probably the easiest to do.

 

[stewm]

Thanks for all replys, certainly given some ideas given that will keep me busy.

 

[zzzjim]

If if it is a boiling issue , setting power a little lower may give clues .

Do you have a tank of steaming hot water in morning , so a tank stat might be an idea

if boiler cannot be left on a lower setting

( FIX ? )
(Less heat , or More flow ... something may be getting blocked )