Replace failed rad lockshield valve - should I replace all??

[Scarum]

Hi

I added Sentinel X400 in preparation to clearing muck out the heating system (vented) and after re-filling and adjusting one lockshield, the lockshield failed and couldn't be repaired (the thread for the packing nut on the valve body sheared off). So I had to get a new lockshield, another flask of X400 and then drain the system including yesterday's precious X400!

What are the opinions on replacing the remainder lockshields when I come to drain out the X400 in a month time, in case of a repeat of the above? House is 15 years old. There are only 4 more rads in the house so not too much cash and time to lose.

Cheers.

 

[Happyplumber]

You may as well change the lockshileds and fit some thermostatic radiator valves,this way you can control the temperature in each room

Make sure not to put thermostatic rad valve where the room stat is fitted

 

[Scarum]

You may as well change the lockshileds and fit some thermostatic radiator valves,this way you can control the temperature in each room

Make sure not to put thermostatic rad valve where the room stat is fitted

Room stat is in the lounge 5 metres from a large double radiator with a thermostatic valve (which I keep on full blast). Heating in house is well balanced.

Just wondered if old shield valves were worth replacing

 

[oldbuffer]

When you do the drain down of the X400, why not just try fully opening and closing each lockshield to check they work mechanically?

Replace any that don't turn reasonably easily, or that "feel" wrong. You could open and close the gland nuts at the same time to see if they work OK, but you'll probably need to repack with PTFE or similar afterwards. If they have O ring seals rather than packed glands, I'd be inclined to replace them regardless as its often difficult and expensive to find the right O rings.

Provided you note the turns (say to the nearest 1/8 turn) to fully close, when you've finished just reopen to the same number of turns to rebalance.

 

[Agile]

As a DIY job for the sake of £25 per rad for a good Drayton TRV and lockshield, I cannot see any reason for not replacing them all.

I dot se why you abandoned the cleansing of the rads after the nut failed. All you needed to do s close the valves on the failed rad.

Tony