Noisy central heating/air

[ChrisinShropshire]

9 months ago, we had the boiler replaced on our (sealed) heating system and the system cleaned. Whilst we accept that when the system is refilled, it is difficult to eliminate all the air.
Since the weather has got colder and the heating is on more, we have noticed that the system has started to get noisier and we are having to bleed the radiators more often. I have checked the strength of the Sentinel using their kit and it is fine. Also, when the water is put on, there is the sound of air travelling along the pipe from the bioler in the garage to the pump in the airing cupboard. I did assume that any air in the pipe would eventually find its way to the radiators and collect there. Once it had been bled away and the system topped up, I did hope the noise would stop.

Any suggestions, please?

 

[KevDIY]

I'm in no way an expert, but if you bled the radiators in a sealed system, did you re-pressurise it afterwards as well? I'm guessing so by what you mention about topping up, but just thought I'd check.

FWIW my system seems to take many months to settle down after flushing/refilling too, but it does generally get slowly better during that time, rather than worse.

EDIT: On reflection, probably not much help, I'm afraid.

Cheers
Kev

 

[ChrisinShropshire]

We keep an eye on the pressure gauge below the pressure vessel and, if it starts to drop below 1 bar with the system cold, then we top it up a bit.

 

[Agile]

Not telling us the boiler make and model is not going to get the best replies!

Put system on heating ONLY and close all rads except one and run for 3 minutes. Start downstairs and then do upstairs last.

Then open another and close the first. Work your way round the system ending with the one where the most air collects.

That MAY help to drive the air out.

Tony

 

[ChrisinShropshire]

Tony,

It is a Bosch Worcester Greenstar 30CDi Classic Regular.

What would be the best pressure to aim at for the system pressurisation when cold?

Thanks, we will try your idea.

 

[Gasguru]

If you're in a normal 2 storey house then 1 Bar cold is fine.

Despite it being a sealed system air in rads can also be caused by a leak.

 

[ChrisinShropshire]

Yes, it is a 4 bedroom 2 story house.

We did have the PV replaced - the pressure was all over the place. since then, it has settled down.

We have not found any evidence of a leak - no damp patches etc. I do check the tun dish and the drain pipe regularly, but there is no evidence of PRV having dumped water.