balancing radiators with TRVs

[bikeman123]

My radiator system is microbore.

Some radiators have Honeywell TRVs http://www.plumbworld.co.uk/honeywell-vt117e-0000-12664

These TRVs can apparently be fitted on either inlet or return pipes.

3 of my TRVs are fitted to return pipes and these radiators all fail to heat up properly and are cool at the bottom. Presumably because water is escaping too quickly and these radiators need balancing.

The question I have is how do I balance these radiators with the TRV on the return pipe? There doesn't seem to be any adjustment to restrict flow.

thanks

 

[D_Hailsham]

There doesn't seem to be any adjustment to restrict flow.

Is there no lockshield valve on the flow pipe into the radiator? If there is, you balance the rad using that valve. Make sure you balance the system with all TRV heads off.

 

[bikeman123]

There doesn't seem to be any adjustment to restrict flow.

Is there no lockshield valve on the flow pipe into the radiator? If there is, you balance the rad using that valve. Make sure you balance the system with all TRV heads off.

mmm that would just restrict water in. I need to restrict water out so that the bloody thing heats up.


Just noticed, below the trv head the pin is surrounded by a plastic collar markerd 1-10 which can be turned down/up. Is this the flow adjustment for balancing the TRV?

 

[JohnD]

mmm that would just restrict water in. I need to restrict water out so that the b****y thing heats up.

wrong.

sorry.

the amount of water that goes in through the flow side is exactly equal to the amount of water that comes out on the return side.

otherwise the radiator will blow up like a ballon

if the water that is going in is hot, the radiiator will heat up.

what is happening that is causing you a problem?

you have to ba;ance the radiators that ARE getting hot in order to divert flow to the ones that aren't

is there a hot and cold pattern to the rads (top, bottom,middle, sides)?

 

[bikeman123]

As I said in my frst post I have 3 radiators with trvs on the return pipes - I have balanced all other radiators by adjusting the return valve - but these 3 have trvs and are not heating up. I need to balance them but because they have trvs on the return pipes I have nothing to adjust.

 

[Norcon]

Try adjusting the flow valve.

 

[JohnD]

you have to close the ones that ARE getting hot.

if the cold ones then warm up you just need to balance the whole system.

if not, then maybe the TRVs are jammed, or else you have a blockage.

old TRVs often jam shut.

 

[bikeman123]

Try adjusting the flow valve.

the flow valves are fully open. closing them just restircts water in and makes the raditor cold.

 

[bikeman123]

If I close the returns any more on the one's that are getting hot, those rads dont heat up either. The TRVs are not jammed.

There's no blockage, the radiators are a only a couple of years old. I have opened the valve drains and water comes out sludge free.

water is running through the radiator too fast - I have a large temp drop between inlet and outlet. Classic stuff that requires the return valve to be shut down a bit. But because it's a TRV I cant do this. Cant be any clearer on this.

 

[Norcon]

bikeman123 wrote

Classic stuff that requires the return valve to be shut down a bit.

Classic stuff that dafty diyers come out with more like.

 

[bikeman123]

bikeman123 wrote

Classic stuff that dafty diyers come out with more like.

So how come you didn't pickup on my post above about the trv having a restrictor adjustment below the trv head? Luckily I found a diyer who knew this and so was more help than arguing with a 'pro'.

 

[ChrisR]

It makes no difference whatsoever which end those trvs are fitted.
If the pipe at one end is hot and the other cold, then one or both the valves is too far closed. Either will do it.

We are right, you are wrong. Get over it!

 

[Norcon]

I'll move the trv to the inlet - it's going to be a lot easier than arguing with a 'pro'.

Go right ahead. You will find your rads still remain cold.
You have a microbore system so I would be looking at a possible blockage or a duff pump not up to the challenge.
The other rads that are heating up fine may possibly need further flow restiction.

The pre-setting calibration scale on the trv is a feature more relevant to larger systems and there purpose is to reduce the function of the lockshield valve but not eliminate it entirely.

 

[ChrisR]

you didn't pickup on my post above about the trv having a restrictor adjustment below the trv head?

You should have known that, it's in the instructions.

 

[Softus]

bikeman You've been told, repeatedly, that you're wrong.

The only thing more bizarre than your misunderstanding of how water flows through a radiator is that you seem to be ignoring the information that you've come here to find.