Diagnosis help required (noisy radiators)

[nadimaj]

Random whirring, gushing, trickling sounds in FF and Loft radiators sometimes during first 5 to 10 mins, sometimes the entire time heating is on. Despite bleeding, flushing, and balancing according to my amateur knowledge, issue remains. Scared to turn them on too early or late because the noise is waking up the kids.

I do hear similar sounds in the manifold from time to time. UFH doesn't seem optimum if I'm honest. Having to switch on several hours before planned usage. I also noticed that the plumber didn't install heat probes into all the UFH zones. Only one of them. I did ask him about this. Didn't get a reply.

Install is less than 3 months old. Plumber never commissioned properly due to fall out with builder. I've offered to pay him to come and finish job off properly but he knows the work is compromised so doesn't want to. Same issue with carpenter. Honour seems to be a dying trait amongst tradesmen sadly.

Video link:

Zone 1=6 radiators on first floor
Zone 2=3 radiators in the loft
Zone 3=1 bathroom towel rail (separate smart switch)
Zone 4=1 shower room and 1 utility room towel rail (separate smart switch)
Zone 5=UFH GF Hallway
Zone 6=UFH GF Front Lounge
Zone 7=UFH GF Main Lounge
Zone 8=UFH GF Shower Room

Apart from the towel rails all zones are zoned via a Heatmiser UH8.

300L Tempest tank, Wilo pump, on setting II
Vailant ecoTEC plus 647

12 way manifold, Wärmer pump, setting II.

Fesh find: Just noticed pressure indicated on left side of manifold might be dropping slightly. Though noise issue started weeks ago.

Thoughts, ideas?

Thank you kindly.

 

[Wayners]

Rust in system causing gas which creates bubbles.
Need cleaner then treatment added maybe?

 

[gas112]

raise pressure to between 2 and 3 and leave one rad on at a time for about 10/15 mins this will usually get rid of the little air pockets .
these rads come with little stickers telling you what side is flow and what is return being installed back to front can stop the air getting out easily so taking rad off wall and turning it around may help if you have any doubles

 

[jeff the gasman]

Probably a faulty pressure sensor on the boiler enabling it to run with insufficient pressure.
Get some water in it as @gas112 says.