a question about radiators

robnye

i have a problem with several radiators........ we had a loft conversion may last year (05), which meant that the heating system was drained down.
since then some of the radiators onyl ever get luke warm. i have done the usual ie vented the rads,

my question is.

the rads have an inlet valve and the output valve.

which one normally has the TRV on ? inlet or outlet?

is there any reason that i shouldnt open the valve (the one without the TRV) fully then control the rad temperature with the TRV. is this efficient

I had read somewhere about equalizing the system, i would rather deal with myself than have to pay a plumber.

Any ideas anyone

Doonhamer

The water will take the path of least resistance so you need to balance the radiators by opening the valves more on the ones that don't get hot and closing more the ones that get hot easily. Fully close the valve on the hot ones then just open it a little bit. You don't need to touch the TRV's only the small valves. Normally the TRV should be on the inlet but modern ones, Danfoss for example, can work on either. It usually says on the box.

Party_Animal

The small valves are called lockshields. They can be shut down completely, then opened gradually as they get hot. You'll have to go all the way round knucking down the hot ones and gradually opening the cold ones. That's assuming there's no air or sludge in the system. Is there a rad in the loft conversion?

alanobrien

Yes, we had exactly the same issue when our loft conversion was done in our old place.

Assuming your boiler pump can cope with the additional height all you need to do is rebalance the system along the lines Doonhamer mentions.

Some TRV's are uni directional meaning thay have to be on the inlet but most these days seem to be bi directional allowing them to be fitted on either side of the rad.
Either way you dont need to touch them.

Flow is controlled via the Lockshield (small) valves.

robnye

thanks peeps,

the TRV's where fitted a few years back, when the boiler was replaced.

the boiler was big/good enough to cope with, if we ever converted the loft.

the loft does have a rad and i had to bleed it a couple of times , now it heats up really well.

a couple of other rads are a little slow to heat up (or luke warm in one case), i had been changing the heat level on the TRV, which works, but then gets to hot......

there is no sludge (or very little) as i flushed the system through twice since the loft coversion, at the beginning of setp 05 when the cooler weather started, this was also to reduce pipe knockin/gurgling, which worked.

I will try opening the lockshield valves on the bad ones and hopefully be able to put the TRV back to a reasonable level (which i think mid range is 3)