Fitting new TRV's

[wrighty208]

Hi, I have a standard open-vented system with an old back boiler behind a fireplace downstairs feeding 7 radiators.

I'm about to fit TRV's on all the radiators and also replace the lock shield valves. (I'll probably take the radiators in the garden 1 by 1 and rinse through with a hose as they are quite old but in good nick!)

Should the TRV's be installed on the 'flow in' or 'flow out' of the radiator? or does it matter?

I'm not going to fit on on the hallway radiator as there is a room thermostat in there.

Any tips - or is this the correct way to do this? Oh, I normally leave my boiler on setting 3 of 5 but I've heard it's more efficient to leave it on Max - is this correct?

Thanks in advance.

 

[D_Hailsham]

Hi, I have a standard open-vented system with an old back boiler behind a fireplace downstairs feeding 7 radiators.

I'm about to fit TRV's on all the radiators and also replace the lock shield valves. (I'll probably take the radiators in the garden 1 by 1 and rinse through with a hose as they are quite old but in good nick!)

Good idea, but don't forget that, with all the water in the rads now down the drain, you will have lost all your inhibitor. So don't forget to buy some when you get your TRVs.

Should the TRV's be installed on the 'flow in' or 'flow out' of the radiator? or does it matter?

In theory it does not matter; but it all depends on the make of TRV.

Most TRVs (e.g Myson TRV4) are bi-direction; so they can be fitted to the in or the out side. You can also have them horizontal or vertical. Other makes can only go on one way. It should say on the box and have an arrow showing direction of flow. Get good quality valves, e.g. Myson, Honeywell or Danfoss.

I'm not going to fit on on the hallway radiator as there is a room thermostat in there.

Someone has learnt to do it right

Oh, I normally leave my boiler on setting 3 of 5 but I've heard it's more efficient to leave it on Max - is this correct?

If the house is warming up quickly enough in the morning and maintaining a constant temperature, there is no need to turn the boiler up. The temperature in the system is effectively controlled by the wall stat in the hall so, even if you turn the boiler stat up to max, the water running through the boiler may never get up to max temperature.

 

[wrighty208]

Thanks for your reply! Unfortunetly I have already bought TRV's from Wickes - I hope they will be ok - I've check teh pack and they do say flow of water in any direction!

One question though - it states they recommend an automatic differential by-pass valve be fitted in all TRV systems - what is this and do I need one?

 

[bengasman]

Bring the wickes stuff back and buy proper ones.
Boiler should be at 65 C or a bit higher to make sure the cylinder gets above 60 C. no technical reason, just lowers your chance of dying from legionnaire’s disease.
Only need bypass if you have 2-port valves