Balancing radiators when fitted with TRV's on Rad outlets

[spyke749]

Hi,

I live in a modern 4 bedroom, 3 storey town house, with a condensing boiler. The boiler is installed on the top floor in a boiler cupboard

All rad's, except ground floor hall way, have TRV's fitted. This is open with the 2 lockshield valves.

Some TRV's are on the inlet to the rads, while others are on the outlet of the rads. I was told by the plumbers who worked on the building site that it does not matter which way round they are fitted.

The ground floor is an open plan area, heated by 2 radiators. These radiators get luke warm at the best.

I have found that by closing all the TRV's on the upper and middle floors, I can get the ground floor rads to a hot temp, which in turn, heats the open plan area nicely.

So, I know that the pipes are clear to the ground floor, and that the rads on the ground floor can get very hot, and heat the area.

After searching the site, I think I need to balance the radiators, to push heat from the upper floors to the ground floor, while still allowing the upper floors to be warm.

I have read this guide and found it very useful :

http://www.diydata.com/projects/centralheating/balancing/radiator_balancing.php

But, here is where I have a question over the TRV's. Can I balance the Rad's if the TRV's are on the outlet of the Rad's, or, should I change the rad feeds etc so that the TRV's are all on the inlets?

The plumbing is all push fit plastic's, so, swapping rad feed and outlet over etc is straightforward and I'm happy to do this.

If I leave the rad feeds and outlets as they are ie: mixture of TRV's on feeds and outlets.... how do I balance the system??

Do I open the TRV's fully and use the lockshield to balance the rad, then use the TRV to set the overall desired temp in the room?

As the pipework is all push fit plastic, I doubt I can use the clip on pipe thermometers referred to in the "balancing guide". are there other types of thermometers that I can use.

Thanks for any advice.

 

[JohnD]

Do I open the TRV's fully and use the lockshield to balance the rad, then use the TRV to set the overall desired temp in the room?

yes, or even take the thermostatic heads off the TRVs.

close the lockshields and open them a tiny amount. Half a turn may be enough.

 

[denso13]

I was told by the plumbers who worked on the building site that it does not matter which way round they are fitted.

On a modern property the valves are 'probably' bi-directional which would be OK.

 

[bengasman]

Even with bi-directional trv's, I find the system works better if they are all on the same side.
All the trv's on the flow side, makes the balancing a lot easier too. Do you have normal valves in the room with the roomstat?
From what I have seen, new builts are often a mess.

 

[ianniann]

As a first pass at balancing you can just use your hands. As you say, your first goal is to get the downstairs radiators coming hot while still having the rest of therm working. You don't need a thermometer to do that. The rest is fine tuning and not really worth spending money on thermometers you don't need for anything else.

Set the TRVs on full and make sure the rooms aren't roasting hot when you're balancing. If the rooms are roasting hot then you'll have to take the TRVs off completely. Once you have it balanced, you can check that nothing horrible happens with the TRVs in their normal positions, but really it shouldn't.

 

[spyke749]

Even with bi-directional trv's, I find the system works better if they are all on the same side.
All the trv's on the flow side, makes the balancing a lot easier too. Do you have normal valves in the room with the roomstat?
From what I have seen, new builts are often a mess.

Room stat is in the ground floor hall way, and the rad with 2 normal valves on it is in the ground floor hall way. All this seems OK.

I'm not a plumber, but, a mechanical engineer and reasonably DIYer. Using my engineering knowledge, it makes sense to have the TRV's on the flow side if using the lockshields to regulate flow.

As the pipe work is all push fit plastic, and I have plenty of spare pipe, I think I may just spend a couple of hours and play with the flow pipes to make sure all TRV's are on the flow side.

 

[namsag]

Even if bi directional its always better to have trv on the flow and lockshield on the return its how as system is properly designed to work so you are doing right to spend time to alter them

 

[spyke749]

Thanks to all replies, confirmed my thoughts and put me on the right path.

 

[D_Hailsham]

Read How to balance a CH system.