Cannot get rid of air in rads and pipes

[Martell]

Hi. I posted a few weeks ago because after my central heating system was drained and leaking valves repaired, I could hear the sound of water gushing and coursing through my rads and pipes. The really helpful forum advice was that there must be air in the system and to keep bleeding the rads. This worked temporarily but the noise came back so I called out another central heating engineer. He said the same - there was nothing to be done except bleed the rads. I've bled them twice a day for 10 days and there is marginally less noise, but I can't cure the problem. All I can do is turn down/off the rad (using the TRV) nearest where I sit as the noise drives me mad. I have a 3-year old Worcester Bosch Greenstar CDi Classic combi boiler. Please is there anything else I can do?

 

[ShaunCorbs]

Have you added inhb ?

 

[Rob Foster]

Hi. I posted a few weeks ago because after my central heating system was drained and leaking valves repaired, I could hear the sound of water gushing and coursing through my rads and pipes. The really helpful forum advice was that there must be air in the system and to keep bleeding the rads. This worked temporarily but the noise came back so I called out another central heating engineer. He said the same - there was nothing to be done except bleed the rads. I've bled them twice a day for 10 days and there is marginally less noise, but I can't cure the problem. All I can do is turn down/off the rad (using the TRV) nearest where I sit as the noise drives me mad. I have a 3-year old Worcester Bosch Greenstar CDi Classic combi boiler. Please is there anything else I can do?

Ok , does the system loose pressure, do,you have to top it up. Chk

 

[dancinplumba]

Have you added inhb ?

why ?

 

[dancinplumba]

probs the TRV

 

[Rob Foster]

why ?

Well it’s obvious, if he is topping up,the heating system then there will be an undetected leak somewhere.
Chk

 

[ShaunCorbs]

why ?

Might not be air but corrosion

 

[dancinplumba]

Well it’s obvious, if he is topping up,the heating system then there will be an undetected leak somewhere.
Chk

What if They ain't and whats inhib got to do with it ? DPK

 

[dancinplumba]

Might not be air but corrosion

Particles ?

 

[ShaunCorbs]

Particles ?

Hydrogen being produced via corrosion

 

[Rob Foster]

So this system is producing more hydrogen every 3 days than ineos Chlor ?

 

[dancinplumba]

I should read posts properly

 

[Chuck]

If the pump speed is set too high, that can cause turbulence and/or cavitation, which be noisy and may cause corrosion and gas evolution.

Old TRVs may be noisy if fitted on the return rather than flow side. More recent ones are more likely to be non-directional.

 

[Martell]

Have you added inhb ?

Thanks for reply. I haven't added anything and I'm beginning to think this might be the problem.

 

[Martell]

Ok , does the system loose pressure, do,you have to top it up. Chk

Hi and thanks. No, the system doesn't lose pressure. It's at 1 1/2 bars. Amazingly, I've been bleeding the rads twice a day for 10 days and i've only had to top up the water once (and then not very much). I wouldn't say I'm getting air out of the system, unless it's possible for air and water to spurt out together. I don't know if that's possible.

 

[Rob Foster]

I suppose your only next option is to,drain the system , refill with fresh water and see ,obviously later on after a few days you will have to add some inhibitors ...centralheatking

 

[Martell]

I suppose your only next option is to,drain the system , refill with fresh water and see ,obviously later on after a few days you will have to add some inhibitors ...centralheatking

Thank you. I suggested this to the engineer who called 10 days ago and he said it wouldn't help. I'm going to have to call him out again as the noise is driving me mad.

 

[king of pipes]

Get one of these fitted a put 2 litres of sentinel x100

 

[Martell]

Get one of these fitted a put 2 litres of sentinel x100

View attachment 35408

Thank you. I'll phone engineer Monday and ask him to help. The radiator noise is unbearable.