TRV wrong way round

[charlie30]

My boiler installer just discovered that a TRV has been installed (many years ago) on the return CH pipe, on a bathroom radiator. Also the TRV has an arrow pointing against the flow!

Performance wise we never noticed there being a problem, I know what needs to be done to put things right.

But I'm wondering how the TRV works.... as it allowed the rad to get nice and hot anyway?

 

[kevindgas]

which ever way it is fitted it will work, although it may be noisy the wrong way round, due to the insides bouncing.
the valve works on air temperature so will shut when the room is the set temperature.

 

[kevplumb]

when the head gets hot it closes the valve as it cools it opens it

the big prob with older trvs being on the wrong end is they chatter when closing

ie the flow of water tends to bounce the washer (its not a washer but you get the idea) on the seating

 

[charlie30]

Thanks for that, what about the arrow? it is a single headed arround and it;s been pointing the wrong way for a few years. Would years of use in the wrong direction damaged it?

We normally leave turned to the max, the needle is still fine and pushes in and out whenI apply pressure to it.

 

[D_Hailsham]

We normally leave turned to the max

Then it's not doing anything! And you won't get any problems with the valve chattering!