How to unstick stuck recessed (slot head) lock shield?

[Flipjango]

We have a new central heating system. It was installed piecemeal as the house was extended, so more rads added on, and they haven’t been balanced properly so the furthest ones in the kitchen extension (which are huge column rads) are not hot enough. simple enough job to balance the rads, or so I thought. But we’ve got weird slot head lock shields and 3 out of 4 of them are stuck fast. All turning them does is make the outer nut turn which eventually leaks. I know it’s the inner slot head screw that needs to be turned whilst the outer nut stays still as I’ve moved it on one of the rads, but on the other three they don’t move at all. In the old style ones I’d have given them a whack with a hammer but there’s nothing to hit. I’ve tried wd40 but nothing happening and I’m starting to thread the screw. What can I do to release them please?

 

[Mottie]

If you have 3 or 4 of them that are stuck, you'd be better off time-wise just replacing them. Do you have a sealed or vented system?

 

[Flipjango]

Its a sealed system @Mottie. Problem is, that's probably something I'd not be comfortable doing myself so obviously more costly as i'd need a plumber. So if any chance I can unstick that'd be good.

 

[kidgreen61]

Usually just need a decent flat screwdriver

 

[Madrab]

Good fitting plain screwdriver and a pair of grips. Push down on the screwdriver with the palm of your hand and use the grips to grab and twist it. Make sure the screwdriver is a really snug fit to avoid stripping the slot out. A plain dumpy can be a good option.

On the original note - what size of pipework has been used to feed these rads and just how large are they? Column rads - hmmmm, every time someone mentions them, it sends shivers up my spine. It's being raised more and more frequently on here.

 

[Notch7]

Column rads - hmmmm, every time someone mentions them, it sends shivers up my spine. It's being raised more and more frequently on

I was doing some site carpentry on a job earlier in the year and there was a plumber there fitting a column radiator…..he was getting really pizzed off, poor chap started shouting at the rad. I believe the problem was the cr@p design of the wall clips / brackets

 

[Madrab]

I believe the problem was the cr@p design of the wall clips / brackets

The hooked brackets they use are a really farf, especially on the larger ones as they use doubles, that and the rads are really heavy unless they are ally ones, so it can be difficult when it's a one man job.

That and they aren't worth the time spent on hanging them, the only positive thing I can say about them is that some of them can look good.

 

[Flipjango]

Usually just need a decent flat screwdriver

Sadly we’ve tried that. Not moving at all.

 

[BlueLoo]

Impact drill and bit?

 

[Notch7]

Sadly we’ve tried that. Not moving at all.

You could try hitting the screwdriver with a hammer, reasonably gently. Sometimes the shock frees it.

You could try penetrating oil

I don’t if a bit of heat on the outside would help.

 

[opps]

Column rads - hmmmm, every time someone mentions them, it sends shivers up my spine. It's being raised more and more frequently on here.

I am a decorator, not a plumber, but I have worked in a number of houses where the column rads have started rusting and leaking.

I suspect that when they started becoming trendy, a lot of firms purchased poor quality ones from China.

 

[gas112]

Some of these screw slot lockshields have a reverse thread try turning it the other way

 

[opps]

To the OP

Please do not think that I am being condescending. I suspect that you need a wider and thicker slotted screwdriver. You should not be strong enough to cam out the head with the correct slotted screwdriver (assuming that you are applying sufficient pressure).

As an aside, I have drained downloads of pressurised systems. As a non-plumber, I find them easier to work with than gravity fed systems. I seldom need to worry about airlocks etc.

 

[Flipjango]

Some of these screw slot lockshields have a reverse thread try turning it the other way

I don't think so. Doesn't turn either way, but the one that does work turns the usual anti-clockwise.

 

[Flipjango]

To the OP

Please do not think that I am being condescending. I suspect that you need a wider and thicker slotted screwdriver. You should not be strong enough to cam out the head with the correct slotted screwdriver (assuming that you are applying sufficient pressure).

As an aside, I have drained downloads of pressurised systems. As a non-plumber, I find them easier to work with than gravity fed systems. I seldom need to worry about airlocks etc.

I'm using the largest slotted screwdriver that fits. Its a very large head. Masses of pressure. Nothing happening.