Central Heating Pipe Noise

[arun30]

Hi

I can't thank enough - but thank you so much for taking time to explain all the steps in detail.

The boiler is now playing again with low pressure - it's now losing 0.1 bar every day. As you said, it might be due to the air being let out by the air separator (not the vent - but a separator from Spirovent).

If you have modern radiators (with the largeish fitting holes at the radiator tops as well as at the bottom) then a handy way to do this is;

I think they are not modern radiators, they are barlo radiators - just like this one - https://www.amazon.co.uk/600x1000mm-Quinn-Barlo-Compact-Radiator/dp/B00ADETULI

I must say some of them are really huge like 500 x 2000 DC.

• Remove one of the inserts at the top of the radiator (they're usually chrome, one will have the bleed valve in, the other will be blank. If you have a spirit level, remove the one at the highest end of the radiator- it should be the bleed valve one but best to check if you can.

• Insert your pipe assembly, threaded end first, into the hole, wind it all the way in

• Switch the washing machine tap OFF

• Fit the washing machine pipe to the washing machine tap, make sure the other end of the pipe is in the bucket (you might want a brick in the bucket on top of the pipe to stop it flying out when you do the next bit)

I mostly understand most of the steps you have listed above. But am bit struggling to understand the bit where I connect pipe with the radiator bleed valve.

One end of the pipe is in bucket, is the other end connected to washing machine tap and the other end of the washing machine tap is connected to radiator valve extension. So is it basically "Radiator bleed valve -> radiator valve extension -> washing machine tap -> washing machine pipe -> bucket"?

Sorry, I know I'm being rubbish, but I know only very little diy.

Thank you , again.

 

[oldbutnotdead]

Hi

I can't thank enough - but thank you so much for taking time to explain all the steps in detail.

The boiler is now playing again with low pressure - it's now losing 0.1 bar every day. As you said, it might be due to the air being let out by the air separator (not the vent - but a separator from Spirovent).

Which is a good thing- if the system is up hill and down dale it'll take a while (if ever) for the air to get out, the separator will help (but they can be quite noisy because of the way they work).

I think they are not modern radiators, they are barlo radiators - just like this one - https://www.amazon.co.uk/600x1000mm-Quinn-Barlo-Compact-Radiator/dp/B00ADETULI

I must say some of them are really huge like 500 x 2000 DC.

Those are modern radiators with the fittings I described (not very well) in the holes at the top of the radiator

I mostly understand most of the steps you have listed above. But am bit struggling to understand the bit where I connect pipe with the radiator bleed valve.

One end of the pipe is in bucket, is the other end connected to washing machine tap and the other end of the washing machine tap is connected to radiator valve extension. So is it basically "Radiator bleed valve -> radiator valve extension -> washing machine tap -> washing machine pipe -> bucket"?

Sorry, I know I'm being rubbish, but I know only very little diy.

Thank you , again.

To get a good flow of water through the system (which will help shift any air pockets in convoluted sections) you need to remove the large hex fitting in the top of your radiator and replace it with the assembly you've built. The washing machine tap then becomes the bleed valve but instead of only allowing a tiny flow it can pass up to 15 or 20 litres per minute- that sort of flow rate will often provide enough momentum to the water/air pocket to overcome gravity (ie the water will push the air downhill and hopefully to a radiator where you can bleed it out). See attached pic

 

[arun30]

To get a good flow of water through the system (which will help shift any air pockets in convoluted sections) you need to remove the large hex fitting in the top of your radiator and replace it with the assembly you've built. The washing machine tap then becomes the bleed valve but instead of only allowing a tiny flow it can pass up to 15 or 20 litres per minute- that sort of flow rate will often provide enough momentum to the water/air pocket to overcome gravity (ie the water will push the air downhill and hopefully to a radiator where you can bleed it out). See attached picView attachment 159593

Thanks again. I got it now - but one last question ( hopefully)

Where does this one go.
https://www.toolstation.com/rigid-radiator-valve-extension/p86447

 

[oldbutnotdead]

The threaded end goes in the threaded hole that you took that chrome and plastic bleed valve out of

 

[arun30]

The threaded end goes in the threaded hole that you took that chrome and plastic bleed valve out of

Thank you so much.

 

[arun30]

Hi

So, we have done the bleeding process and switched on the heating, it was quiet for a moment and then - it happened.

As soon as we used the water tap (yet to identify which one caused the problem - hot or cold tap), the central heating pipes are started with the air noise. Somehow opening bathroom or kitchen water taps are causing (or sending) air to central heating pipes.

It seems like the water tab is somehow sending air to central heating pipe. Is this an issue with by pass valve.

Its looks like we have now narrowed down the problem, but we don't know how should we fix this problem.

Any suggestions.

I will also open a new discussion thread, just in case if no one notices this old thread.

Thanks

 

[oldbutnotdead]

Curiouser and curiouser
How was your hot water heated with the old wau setup?
Running a tap shouldn't affect the heating pipework at all.
(Mad but possible) does the heating system pressure drop when you turn a tap on? Do all the hot taps cause the boiler to fire (in hot water mode) and eventually run hot?
Do all the cold taps work?(ie cold clear water out of them)

 

[arun30]

Curiouser and curiouser
How was your hot water heated with the old wau setup?

We had WAU (in ground floor) for central heating and 23kw Vaillant in loft for hot water. We basically removed WAU and replaced 23 kw boiler (used for hot water) with 43 kw by reconnecting existing domestic hot water pipes + installed brand new central heating pipes from the new boiler to all the floors and rads.

(Mad but possible) does the heating system pressure drop when you turn a tap on?

If we open the hot water tab when the boiler is already running for central heating, the pressure fluctuates by 0.2 bar, I think that it actually rises most of the time.

Do all the hot taps cause the boiler to fire (in hot water mode) and eventually run hot?

Yes, the boiler fires whenever we use hot water and yes, we get hot water in all the taps.

Do all the cold taps work?(ie cold clear water out of them)

Yes, they all work - but I should mention that the engineer increased the main cold water pressure when he initially began this work

By the way I can now confirm that opening hot water tap is causing the noise in central heating pipe, not the cold water tap.

 

[arun30]

He has fit non-return valves in dishwasher and washing machine and installed another one in domestic hot water pipe which is closer to the boiler, but it didnt solve the problem