TRV problems high pitch squealing

[Rustynut]

Good evening - I wonder if anyone can shed some light on this.
Squealing high pitch TRV's when reaching the required shut-off temp.
I understand its probably the pressure in the system making the pin in the TRV vibrate. Or pump turned up too high - which I guess would cause the same effect of raising the pressure.

Firstly I'm in France and have a new french (Frisquet) sealed system running at 1.3-1.4 bar.

The house was plumbed before we bought it by Spanish plumbers. French / Spanish - recipe for disaster. They cant even agree on the size of pipe they use!
So we're in copper 15mm.
The TRV valves are cheap Spanish ones. I would fit Drayton (and have fitted many of them in England with never a sound out of one) if I could find 15mm into half inch rad connectors (the spanish ones of course!)

So should I drain down again and get some more upmarket spanish valves - or get a degree in nuclear physics and turn the pump down a notch - except its a French pump buried within the boiler and seems to have no adjustment via the electrical input panel.

Things were easy in England - vented or pressurised, 15mm with olives. Easy. Here its 15mm 16mm 18mm and multi layer all in the same house - and a variety of different seals, rubber, plastic, long olives and string!

Has anyone had this amount of noise out of a TRV?

Any help much appreciated.

 

[ShaunCorbs]

Are they on the flow eg the hottest pipe ?

 

[Rustynut]

Hello and yes they are. TRV's on the flow side.
The balancing valves are at the bottom ( which are all 8mm allen key type and leaking coz they're the cheap spanish ones.) I need to upgrade those too - but I cant find the plastic olive fittings apart from on the cheap ones and the metal spanish long olives leak too.
I've never had so many drips out of a heating system in 40 years and I've fitted full systems in my first flats in London with not one drip.

 

[John.g]

As a temporary measure suggest reducing boiler flow temperature to say 50C which means TRVs opened more for same mean rad temperature, less squealing?. If not a combi you will then have to reduce the cylinder stat to 45C and boost the temperature to 60C once per week for legionella protection.

 

[Scott_D]

Can you post a picture of the vakve?