radiators not working properly

[wendy wu]

i have 2 radiators in my living room and the thermostat is set at 20. My one radiator is on number 4 and i have no problems with it but at the other end of the room the radiator on same number keeps going cold before the thermostat has turned heating off if i turn it up to 5 it comes on is this normal and if not what could it be.

 

[gasandoilman]

When it does come on does it get nice and hot all over?
If so rules out a flow problem

You can sit a thermostat on the valve to see what the temp is when it goes cold and do you have anything in front of rad that can conain heat like a rad cover or sofa ect

 

[seco services]

if the wall stat is in the same room as the rads with trv's they will play against each other.
rooms with wall stats fitted don't useally have trv's on the rads.

 

[wendy wu]

when rad is on number 5 yes its fine and thermostat is not in same room as these rads.

 

[D_Hailsham]

My one radiator is on number 4 and i have no problems with it

Do you means that this rad never goes cold? Rads with TRVs are supposed to go cold!

When the TRV reaches the set temperature it closes the valve, so no more water will flow through the rad; the rad will then cool down. When the temp in the room has dropped a few degrees the TRV will open the valve and the rad will start to heat up again.

If the TRV on this rad is never closing down it could mean that the rad needs balancing.

at the other end of the room the radiator on same number keeps going cold before the thermostat has turned heating off if i turn it up to 5 it comes on.

Sounds as if this stat is behaving as it should.

You say the thermostat is set to 20C. 4 on many TRVs is also about 20C, so there is a danger that the wall stat may shut down before the TRV operates. It might be better to set the wall stat to, say, 21C.

 

[wendy wu]

Thanks for all of that it makes sense, from what you said i think its me thinking something is wrong and it is working as it should.