Rad valves in bathroom

[Deanrowland]

Hi guys, long time lurker, infrequent poster...

I have a rad in my bathroom with a TRV, simple enough so far...
The pin on the trv has seized.
I have tapped, sprayed wd40, tapped again, sprayed, twisted, pulled, tapped, sprayed... And the pin just wont open,so ive come to the conclusion its probably had its day...
Should be within my DIY skills to replace but i have a couple of questions please.
1. Is a TRV sensible in a bathroom? Ive read they can play up due to conditions and, it clearly has...
If not, what is the fancy name for a non trv replacement?
2. Swapping the valves only, is ok... Right?
I dont need to be replacing olives etc do i?
3.sizing, how many sizes are there, mines a small copper pipe so assume threads will bebtgevsamevetc?
4. Anything else worth knowing?
Normal system, tank in loft, boiler in kitchen, drain point on rad near door


Any help would be great, Cheers

Dean

 

[WC1]

Should be do-able, the tricky bit is minimizing and dealing with the water and sludge that will want to acquaint itself with your carpet.
YouTube is your friend.
View: https://youtu.be/VkLIRP2ZVqw

Post up some pics "small copper pipe" covers a multitude of sins...

 

[Ben-gee]

Grab hold of the pin with a pair of grips and wiggle it like you’re trying to get a mugger off your sister.
I’ve never come across a pin that won’t move with enough persuasion.

 

[Deanrowland]

Cheers, this is the offending item, it doesn't help that the pin is slightly tapered so its hard to grip it.
The black bit has a hex on it, does this mean it will turn if tried?

 

[shyguy2005]

Cheers, this is the offending item, it doesn't help that the pin is slightly tapered so its hard to grip it.
The black bit has a hex on it, does this mean it will turn if tried?

Hit it with a hammer