Heating Bangs when switching off.

[Paul Cooksn]

Forgot to say, that as you mentioned the amount of muck in the magnet suggests that the system needs a good clean.

Thanks for your advice. The pipe or pipes running across the garage ceiling are the flow and return to the boiler. The vent pipe is in the airing cupboard and goes about 18 inches abouve the header tank in the loft. When filling the heating back up after draining it doesn't bang, it's only when all the air is out the system so similar to your radiator test. Turning the pump down reduced the bang noise.

Cheers.

Paul.

 

[SavageW]

Got a picture of the new by-pass that’s been fitted ? Hard to tell from airing cupboard picture but is the open vent an cold feed teeing in just before pump

 

[Paul Cooksn]

Got a picture of the new by-pass that’s been fitted ? Hard to tell from airing cupboard picture but is the open vent an cold feed teeing in just before pump

 

[ShaunCorbs]

Where's the bypass valve all I see is a full bore ISO valve ?

 

[SavageW]

The valve put in on the by-pass looks like a ball fix turned 1/3 off have you tried opening this fully an seeing if this stops the banging
*shaun beat me to it,but that isn’t correct for a by-pass that’s why you still have the banging

 

[Paul Cooksn]

The plumber said it didn't need one, I thought it might and I asked again whether it needed to be 22mm. I can change it myself if you are able to advise what to get and where to put it. If the valve is fully open then yes it does stop it banging.

One question, I have lived in the house for 13 years without a single bang. Why would this start after removing the radiator.

 

[Paul Cooksn]

The valve put in on the by-pass looks like a ball fix turned 1/3 off have you tried opening this fully an seeing if this stops the banging
*shaun beat me to it,but that isn’t correct for a by-pass that’s why you still have the banging

The plumber said it didn't need one, I thought it might and I asked again whether it needed to be 22mm. I can change it myself if you are able to advise what to get and where to put it. If the valve is fully open then yes it does stop it banging.

One question, I have lived in the house for 13 years without a single bang. Why would this start after removing the radiator.

 

[SavageW]

I didn’t even pick up on that it was 15mm,that won’t help an then with the type of valve that will neither. You’ve said that with it fully open the banging stops.I could only say that since the 13years you’ve been there that the pipework /heatexchanger has become restricted.

 

[Paul Cooksn]

I didn’t even pick up on that it was 15mm,that won’t help an then with the type of valve that will neither. You’ve said that with it fully open the banging stops.I could only say that since the 13years you’ve been there that the pipework /heatexchanger has become restricted.

Cheers for your help. Could you tell me what valve I need and where it should go.
I assume the valve is operated by bar pressure

 

[SavageW]

bypass valve open vented system - Google pretraga ask your plumber who installed your by-pass to come back an rectify

 

[Paul Cooksn]

bypass valve open vented system - Google pretraga ask your plumber who installed your by-pass to come back an rectify

Your a star cheers. Is it in the right place above the valves

 

[Paul Cooksn]

One final question.

Should I fit the new 22mm auto bypass valve to replace what is there or should it go after the pump but before the motorised valves.

Thanks. Paul

 

[Last Plumber]

Has a Plumber put that in?

 

[Paul Cooksn]

Has a Plumber put that in?

Yes.

 

[Paul Cooksn]

Has a Plumber put that in?

Hi sorry couldn't reply properly earlier.

Yes following your previous advice a plumber did fit it, new pump, new valve and I fitted the magnaguard. It stopped for a few days but when the air was completely out of the system it started again. I questioned whether a 22mm auto bypass valve was required and he said this will do the same.
I am perfectly capable of fitting it myself but am not sure where to fit it. Do I install in the same place or before the valves but after the pump.

I even re installed the radiator and it bangs.
Cheers. Paul.

 

[Last Plumber]

It will do there if it is 22mm and automatic. I am presuming you have a 3 mtr min loop from boiler and back to boiler via by-pass?

 

[Paul Cooksn]

It will do there if it is 22mm and automatic. I am presuming you have a 3 mtr min loop from boiler and back to boiler via by-pass?

View attachment 31830

The distance from the boiler to the by pass is about ten meters. I will change the size of the plumbing and use solder joints as it looks a bit messy. I can fit it somewhere else if it works better. I would rather it be correct. Wish I had done the work myself.

Does the pressure have to be regulated by the pump flow speed. Cheers.

 

[Last Plumber]

One question, I have lived in the house for 13 years without a single bang. Why would this start after removing the radiator.

Because the Rad acted as a by-pass and you removed it!

 

[Last Plumber]

The distance from the boiler to the by pass is about ten meters. I will change the size of the plumbing and use solder joints as it looks a bit messy. I can fit it somewhere else if it works better. I would rather it be correct. Wish I had done the work myself.

Does the pressure have to be regulated by the pump flow speed. Cheers.

It's fine there, 22mm with either a straight valve like the one I showed you or an angled one where the elbow is

 

[Last Plumber]

Does the pressure have to be regulated by the pump flow speed. Cheers.

What speed is the pump on now?