Rad sizes/BTUs

[Alison556]

I've had a wee looksie at the TRV and the valve on the return side. Can I just check something before I touch anything.

On the TRV - do I need to undo that large nut to take the dial bit of the TRV off? I don't want to go undoing anything and springing a leak!!

On the return side, I unscrewed the valve cover and the bit for adjusting it is strange (to me anyway) - it's like a hex socket but female (?) as opposed to male (hope I've got that right). What do I use to adjust that? Is it an Alyne key you use on that?

 

[Softus]

somehow managed to pull it off and the next thing, had Niagra falls in the bathroom, with me screaming for a screwdriver to turn off the isolator valve!!

You should keep one of these in the toolbox, which are very handy and can buy you time to think about what to do next:

 

[Alison556]

I've got a couple of them. I even used one - do you know how far you can make water spray with one of them?

 

[Richard C]

On the TRV - do I need to undo that large nut to take the dial bit of the TRV off? I don't want to go undoing anything and springing a leak!!

Yes, the large nut pulls the TRV body down onto the valve pin; once removed you should be able to see if the valve pin move OK.

it's like a hex socket but female (?) as opposed to male (hope I've got that right). What do I use to adjust that? Is it an Alen key you use on that?

All the ones I’ve ever seen have the standard 2 flats or a square which the standard valve cap fits; are you sure you don’t have a valve cap somewhere else on the system somewhere that fits it. It’s difficult to tell without seeing it but it could be an Alen socket head or it could be a Torx type fitting.