Your starter for 10 (TRV Fixing

[EricP]

Is a 15mm street elbow good enough to go straight into the compression fitting of a rad valve, or should it be a piece of normal 15mm pipe?

And what's the best way to hold a TRV to tighten the rad tail nut? There is nothing to really grip on the L shaped body, and some of my tails are smooth steel tube that require good compression for the olive to grip.

Finally your Bonus Question.

Which is best, a horizontal fitted TRV or a vertical one?

A horizontal would be away from the rising heat of the pipe and more able to reflect the room ambient temperature?

[Christian McArdle]

Vertical looks better, whilst horizontal works better. They also work very slightly better on the return, as the water temperature is lower there, so affects the measurement less.

Christian.

[EricP]

I was bunging them in horizontal where I could, SWMBO liked them.

Your point about the return is very useful and I will change a couple around as a result. (The TRV's are non directional)

Many thanks :))

[Christian McArdle]

Well, if you've got the time! The difference is marginal enough not to bother changing existing ones, I'd have thought.

Christian.