Question about lockshield

[Decker]

Apologies if this is very basic but I am getting very little heat to one of my radiators. I am testing very basic things to see if that resolves it and one of these is ensuring the lockshield is fully open. However my lockshield appears to be of a different design to standard (http://www.judgeelectrical.co.uk/images/central-heating/adjust-lockshield-valve.jpg) and I wanted to know if I should turn the square block within the column part on the left of the photo with a radiator key or the top brass fastener or the bottom brass fastener both on the right of the photo
View media item 84102Many thanks in advance

 

[Terry lambert]

The brass section/ spindle is what is used to open and close the valve.

The part to the left is a drain point.

Try shutting other rads to see if the rad then gets hot

 

[Slugbabydotcom]

The square peg that looks similar to a bleed valve is in fact a drain off point for the radiator. The water comes out from underneath. Rotate the stem at the top right in an anticlockwise direction to open the valve as indicated on your pic.

 

[Terry lambert]

If there is a thermostatic valve the other end, the pin might be stuck

 

[Decker]

Thanks - will give that a go
Logically if the rad key releases water from the rad then it should also release from the lockshield as you both pointed out - don't you just love hindsight.

 

[D_Hailsham]

I am testing very basic things to see if that resolves it and one of these is ensuring the lockshield is fully open.

One of the basic things to check is that the LS valves are not fully open as it tells you the system has not been balanced.

Check how far open all your LS valves are. If most of them are fully open, or only closed one to 1½ turns, the system has not been balanced.

 

[Decker]

Again thanks for all the advice.
I have turned all the thermostats on the rads in the house to 0.
Rad in question I open the lockshield fully open and set the thermostats to its highest setting.

Once the heating was on the rad in question was luke warm at the top but cold at the bottom. In addition the flow pipe was cold but the return was warm (warmer than the luke warm top of the radiator).

In addition 2 other radiators in the house were pumping out heat - even though the thermostats were set to 0.

For the 2 radiators I assume this is just a broken thermostat?

As for the rad in question - any ideas?

 

[D_Hailsham]

I assume that when you say 'thermostat' are you talking about thermostatic valves on the rads.

If the rads still get hot when the TRV is set to 0, the TRV is probably sticking open. Remove the TRV head and check that the pin can be pressed down and springs up quickly when released. If it's sluggish lubricate the pin with silicon lubricant. If it can't be pressed down, tap the side of the valve with a hammer to release the pin.

If the 'flow' pipe is not so hot as the 'return', it means that the TRV has been put on the return end. This is OK, provided the TRV is correctly installed. Look for one or two arrows on the valve body. If one arrow, it must point in the direction of flow, even if the TRV is on its side. Towards rad on flow (hotter) pipe; away from rad on return (cooler) pipe. If there are two arrows the TRV can go on either way round with the head vertical or horizontal.

Your system needs balancing.

 

[Decker]

Sorry yes meant thermostat radiator valves.
I have terrier trv's, can the heads be removed independently from the rest of the trv without having to drain the rads (never dealt with trv's hence my question) and if so how?

As for the rad in question, the flow pipe is cold, it has the trv on it set to 5 and the arrows show flow in both directions. The return is showing some heat (as is the top of the rad) but the level is a very small rise from cold/off.

 

[WabbitPoo]

What sort of system do you have? If a combi then make sure your system is up to pressure (about "1" on the dial) when the system is running.

Have you also done the basics of venting any trapped air in all the rads?

 

[D_Hailsham]

You turn the knurled silver ring under the head anti-clockwise (looking down) to remove the head. No water will leak out.

This will expose a pin, which you should be able to press down against a spring - use something hard to do this. It should spring up when released.

If the pin can move down but comes up very slowly, lubricate it with silicon lubricant - not WD40 which will rot the seals. If the pin cannot move down - valve stuck shut - tap the side of the valve with a hammer to see if it will release. If nothing works, you will have to get a new TRV.

The TRV has been put on the return on your rad!

Your system may need balancing.

 

[Decker]

Thanks all for your help so far. I have bled all the rads and closed all the lockshields and set all the trv to 0. I then opened the lockshield for the radiator in question all the way open and set the trv to 5. I then turned the heating on. With my plan being that this would be the only radiator to get warm. However it was still the same (Luke warm at top and cold at bottom).
Also the flow and return pipes out of my boiler split into 11 individual pipes each, via a manifold? (see attached photo -upside down). I thought with this set up there is more chance of the heat reaching the rad in question that with a traditional pipe layout.
Any ideas?
View media item 85114

 

[andytw]

I have had to change a couple of TRV heads recently as the head was broken and kept the actual valve closed. You have Terrier, mine were Myson, but might be just worth seeing what happens with the TRV head removed.

andytw

 

[Decker]

The same lock shield leaks when turned fully clockwise (closed) but not when open, in addition I can turn the lock value with my fingers (ie there is no resistance) but all other lock shields require plyers/wrench.
I guess I need to get a professional in but any suggestions why it is leaking when closed?