TRV problems

Flower_Power_mark_2

Hi,

I'm currently having problems with the TRVs on my radiators and wondered if anybody here could offer some insight. The first problem is that when I turn it down to say 3 the radiator will turn off. So in other words i either have a radiator on or off there is no middle ground where I can turn 1 room down a few degrees. Is this normal. I have a BAxi duo tec 28 he boiler which is linked to a thermostat for the house. Does this thermostat render the TRVs useless?
My second problem is that when the boiler starts up or goes off it can make a banging noise. This does not happen all the time. I posted about this issue prevously and got some very helpful answers. However I have just noticed that the first radiator after the boiler has a TRV on either side of this. Once again is this normal? Or could this be the cause of the banging noise.
Final question sorry doe TRVs always go on the right hand side of the radiator as you look at it?

I have previously spoken to the plumber who installed the boiler and was told the banging could be due to air in the system and to give it a couple of months.
Thanks very much for any help that can be provided

1984ReturnsForReal_2

Have all the rads got a TRV fitted?

Flower_Power_mark_2

All of the rads have got trvs on apart from the one. One of the rads has got a TRV at both ends and this is thr 1st rad after the boiler.

bob_a_builder

never heard of having 2 TRVs on one rad

TRV should be fitted on input side of rad (or is it output side - I forget) - might vary by make, I remember the instructions with the valves were specific -
you can tell which is which - input pipe get hottest first
If its wrong then can cause noise from pipes, I put one on wrong end and we had banging too - so having 2 on one rad must be wrong ?

no point in having a TRV and thermostat in same room - they will fight each other

good read

(not a builder btw)

ormus

the convention is to fit trv,s on the right hand side, but it can fit either side depending on the flow & return pipework. a bit like sink taps.
ive never heard of two trv,s on the one rad. and one rad should always have no trv fitted, usually the bathroom or the hallway rad.

Flower_Power_mark_2

Thanks for the replies and it appears that the 2 trvs on 1 rad could be what is causing the banging.
There is 1 rad with no trvs on and this is in the bathroom.

bob_a_builder

There is 1 rad with no trvs on and this is in the bathroom.

Its of course OK not to have them in any room you choose, people generally like a warm bathroom, but its important that they should not be in same room as a room thermostat !

roger196

Most modern TRV's are bidirectional, they can be fitted on either the flow or the return but not both. These have two arrows on the body. Some older ones can only be fitted on the flow side only. These will usually have a single arrow on the body.

Blackpool_Saver

TVR is a car factory near me that closed down

gas4you

Don't know what you're expecting from a trv, they are either on or off depending on the ambient air temperature around the head.