3 way mid position valve banging

[Shaun1973]

Need help. I have just fitted a new Honeywell mid position valve and now I get a loud bang coming from it when hot water or heating comes on. B is going to the hot water tank A to the rads. what can be causing this and can it be fixed

 

[terryplumb]

Are you certain the banging noise is coming from the valve?

 

[Shaun1973]

Yes certainly sounds it. When I turn heating on at switch it bangs after a few seconds while pump and valve shake

 

[terryplumb]

Could it be banging from boiler and pipework ? That would be Indicative of a lack of water / air present in the system.
Unclip the actuator from the valve body ,momentarily turn on the boiler and see if banging is still happening.

 

[Shaun1973]

I Haven’t bled anything and I think the tap valves either side of pump were inky half open before. I’ve opened them fully since fitting new valve. I’ve taken the old actuator off old body before (new one fitted ) and if I slam open the valve with pull running it’s exactly same noise

 

[terryplumb]

Is it only the actuator head that you replaced ,not the complete valve including the brass body on the pipework ?

 

[Shaun1973]

I’ve changed the whole head and actuator…. Before I’ve fitted 2 new actuators left old body it’s been fine. It’s only started doing it since o fitted whole new body etc. when I changed actuator before if I turned pump on without actuator fitted and manually tried to move valve it banged across making exact same noise it’s making now

 

[terryplumb]

Unclip the actuator from the valve body ,momentarily turn on the boiler and see if banging is still happening.

And if you do the above ,now , what's the result ?

 

[Shaun1973]

I’ll take actuator off In morning and try it. Let you know what happens

 

[ianmcd]

looks like your pump is fitted the wrong way round, on the actuall body of the pump you will see an arrow, it should be pointing towards the AB port on the mid poition valve, if it is pointing away from it that is your problem

 

[Shaun1973]

No pump is fitted right way

 

[oldbuffer]

1. Doesn't look like a Honeywell valve, unless they've started colouring the cover blue.
2. Are you sure its a like for like replacement for what was there before, or could it be a diverter valve?

 

[Shaun1973]

Yes it’s def a Honeywell one I’ve just not taken the blue sticky cover off the box that’s all. It doesn’t bang all the time it seems to be when bump kicks in and valve is changing over