recently i fitted 2 new radiators , 4 new lockshields/TRVs and refilled the system with inhibitor.

I then balanced the radiators with a dual sensor thermometer – – as i got pissed off with the laser thermometer method i used last time i did this.

I set them all up to have 12degrees C drop between inlet and outlet when TRV is fully open. which equates to between 1/4 to a full turn the further you get from the radiator. The inlet temp at the first rad tail is 49deg C

My issue is the radiator in my bedroom – which is one of the originals (3 years old delonghi) with one of the original danfoss TRV and lockshields Whistles like a banshee when starting from cold in the morning(at 4am convienantly….:() unless i open the lockshield up a turn or two…. its only that radiator. No air coming out of any rads when i tried rebleeding them , i dont seem to have a leak in as much that the pressure isnt dropping at all and i did a 3 bar pressure test for a good while before i filled with inhibitor and the rads all get uniformly hot.

Its a 3 year old grant boiler , with radiators ranging between 3years and 1 week, its always had fernox in it (the antifreeze one) and it has a magnaclean on it and theres a dump radiator in the system

Now i realise the obvious fix is obvious – leave the lockshield open But i want to know why its doing this …its slightly irritating in the morning…..makes me grumpy for the rest of the day.

cheers

leave the lockshield open

this.

I reckon it will be some turbulence around the valve seat/jumper at a particular flow rate.

just twiddle it out.

Stoner – Member

I reckon it will be some turbulence around the valve seat/jumper at a particular flow rate.

+1…..

Is the TRV multi-directional ? You could try swapping the TRV and lockshield over as it sounds like there’s a pressure drop over the lockshield.

Sorted. No noise today.

User error. Held a stati cold pressure test at 3 bar for a couple hours.

How ever in use it was sucking air in from a loose compression fitting on the bottom of one of the original trvs upstairs.

Yesterday It was running down the rad tail to under floor and i lost pressure ( for first time in 2 weeks) .then i noticed a damp patch in the downstairs hall,

Got 4 full turns on the fitting without trying. All tight , holding pressure , roofs dried out and most importantly dog gone quiet now.

Thank ****. Didnt get woken at 4am today 🙂

I see you’ve sorted it. Could it also be the highest rad in the system, or the first on the top floor supply? Just curious.

It is the first on the upstairs system – it has also become the highest point in the system due to fitting 2 modern tripple panel low height rads in other rooms.

But theres no doubt i had a leak due to the fact i ha a wet roof and wet rad tail- neither were wet when i posted the op- first thing i looked for was a leak!

I believe that’s where both gas and trouble collect, but perhaps not the force to undo the fitting.