One cold rad, cold pipes to it and missing lockshield

longwalks1

Have just refitted our hallway radiator that has been off for about a year due to renovations.  Turned on heating and every radiator is red hot apart from the one refitted.  

TRV is fully open.
both pipes to and from the refitted rad are cold.  All other pipes to every other rad are hot.
lockshield on refitted rad doesn’t have the pin that you get an adjustable spanner on to open it.  When you unscrew the lockshield polished cap expecting to see the pin, it’s just a brass hole.

confused, and can usually get my head around basic heating/plumbing 

ThisIsWeird

Photo of this missing thingy, please.

Have you refilled the rad? If so, how? Which valve provided the water to refill it?

molerat

Also have you checked the TRV pin is not stuck closed.

Remove TRV head and check pin moves in and out freely.

Is it a "hole" or a hex allen key hole ? 

Some lockshields have this instead of the external tap adjuster.

grumbler

One radiator in the system is supposed not to have a TVR - and usually it's the hallway  one.

Martin_the_Unjust

You probably need to balance the system, pretty simple to do and there are plenty of ‘how to’ guides on ‘tinternet.

Veteransaver

Is the non trv side actually open? Ie does the rad have any water in it, if you bleed it does water come out (after any air)

Veteransaver

grumbler said:

One radiator in the system is supposed not to have a TVR - and usually it's the hallway  one.

Not necessarily, it's common now for systems to have a bypass valve.

FreeBear

Veteransaver said:

grumbler said:

One radiator in the system is supposed not to have a TVR - and usually it's the hallway  one.

Not necessarily, it's common now for systems to have a bypass valve.

Traditionally, the CH thermostat was placed in the hallway and no TRV fitted to the radiator. This is so that the TRV isn't shutting off the radiator before the area is warm enough to trigger the thermostat. The bypass thing is just a side effect of not having a TRV.

Albermarle

Also have you checked the TRV pin is not stuck closed.

Remove TRV head and check pin moves in and out freely.

The first time I put the CH on every year at least one radiator stays cold, due to this problem.
A squirt of WD 40 and pushing the pin up and down manually with a pair of pliers always works.

ThisIsWeird

Albermarle said:

Also have you checked the TRV pin is not stuck closed.

Remove TRV head and check pin moves in and out freely.

The first time I put the CH on every year at least one radiator stays cold, due to this problem.
A squirt of WD 40 and pushing the pin up and down manually with a pair of pliers always works.

Every home - every home - should have a wee tub of silicone grease, imo. 

Stuck TRV pins? Apply a wee smear of sili-g around the pin's base, and press the pin down a few times. Leave a smear surrounding the pin at its base, and that should keep it sorted.

Just been outside - between showers - replacing a headlamp bulb on a C4 Picasso. Like most modern cars, space is tight - squeeze fingers down between fuse box and back of headlamp bowl to try and undo - anti-clock - the plastic cover. Darn, it was tight, but it finally loosened. One leccy plug was also stuck quite firmly, but finally came loose with an unpleasant scrape. A wee smear of s-g on the cover's rubber seal, and the cover literally put itself back on. Literallyish. Ditto on the plug socket before reinsertion - smooth as a smooth thing, and it should prevent tarnishing or corrosion there. I can hardly wait for the next lamp to blow...

During the past hot summer, a visiting friend in an oldish car announced their arrival by the dry scuffing, almost tearing, sound of their car door being opened. The lightest of wipe-overs of sili-g made it noise-and-sticky-free.

And then you use it for plumbing.

Eg: https://www.ebay.co.uk/itm/234897000468?

(Declaration of interest - the guy is offering me a £iver for every tub sold).

longwalks1

Thank you everyone. As per molerats 3rd post it was in fact an Allen key fitment to open the lockshield. 

Never seen one before.
opened it and a fully hot radiator within a few minutes. Thanks again everyone