trv's have been fitted to NON flow end of new rads is this o

[ianpetch]

we have had 4 new rads fitted 3 are replacements and the 4th is a new room with new rad.
All tvr's have been fitted to the outlet/cold end of the rads. Is this correct as all the old rads in the house are piping hot, the new ones are barely warm. The inlet/flow end is boiling to touch but the end with the tvr is cold.

Are they fitted incorrectly?

 

[GasMan1965]

Most TRV's are reversible so should be ok,,, make sure the other end is open enough !!

 

[Agile]

Current TRVs can ( mostly ) be fitted to either flow or return.

Most people still fit them to the flow.

There is an argument that fitting them to the cooler flow end means that they are more responsive to the room temperature rather than the heat from the supply pipe.

Tony

 

[wilder74]

New trv's are made to fit on flow or return,so as long as they have arrows on them showing they can flow either way your ok

 

[gigz]

If the're danfoss, take the head off the trv and check the arrow is the right way round. It may also be a balancing issue ( see F.A.Q.)

 

[ianpetch]

I have checked oter end and valves are all open.
Radiators are not getting hot at all. Inlet pipe is very hot to touch but the outlet (fitted with trv) is stone cold no heat at all.

 

[GasMan1965]

Open up TRV's fully on rads not working and close all other to see if its an air lock !!

 

[kevplumb]

take the head off the trv

 

[htgeng]

If I remember to mark up the rads, I put them on the return as per comment from Tony. Also they will run a lot cooler so should have a longer working life. Maybe thats a conflict of commercial interest?!?

 

[heatingman]

Work better on return end, when on flow for hours the trv wax element will become heated by conducted heat and start over compensating.

 

[D_Hailsham]

the trv wax element will become heated by conducted heat and start over compensating.

Only the cheap TRVs use wax elements. Quality ones, such as Drayton and Danfoss, use a liquid or a gas as the temperature sensing medium.

As for the water temperature affecting the working of the sensor, Drayton say that it amounts to 0.8°C.