Trying to balance 4 radiators one has no TRV only one hot

[Jason P]

We just moved into a new build house two months ago. Haven't really had to use the heating upstairs until now. Downstairs has a thermostat in the living room and 5 radiators it controls that all work fine. Upstairs has a thermostat and 4 radiators and only one of them is getting hot.

This is the radiator in the master bedroom right by the thermostat, and it has no TRV just a lockshield valve on both ends. This one gets really hot really fast, and no heat seems to go to the bathroom or kids rooms even when those TRVs are turned all the way up.

I read that the rad by the thermostat shouldn't have a TRV so that water can always flow around the system, but I am not sure which side of the radiator is the water into it and which is the water out towards the rest of the rads. Am I to have the 'in' valve fully open and the lockshield out mostly closed?

I'm trying to find this configuration but I can't get the others to heat up at all now. Before they got warm after a long time, so I started trying to balance them. So at least I know they all work. I'm concerned now I might be restricting the flow to this one radiator from the boiler, but even if I turn both the valves fully anticlockwise, the next radiator in the sequence (bathroom) doesn't seem to warm up,

Any help or advice I would greatly appreciate. Thanks

 

[SimonG]

Check motorised valve is opening fully open.

Turn off downstairs and shut down the one hot one upstairs. Take off trv heads and make sure lockshield open.

Is it a combi?

Or just get the builder to sort. At two months old I would want it to work perfectly without having to feck about with it.

 

[ballvalve]

Turn the boiler off until it cools down then get some one to turn it on. You can put your hand on the pipework in the master bedroom to see which pipe gets hot first so you will know, flow or return.

 

[ballvalve]

See if the pins are stuck in the trvs they should move and down.Up is open down is closed.

 

[Jason P]

Am I right in thinking the water comes from the boiler into the radiator in one pipe, and then out the other into the next radiator, and so on in a long chain. Ie, it doesn't go back to the boiler between radiators or anything like that?

It is a combi boiler for hot water and the radiators. Should I have the flow to the first radiator fully open? and the lockshield coming away from it mostly closed? Or both mostly closed? I don't want to risk backing the hot water up in the boiler which I read is a problem (hence why theres no TRV on the first radiator)

Downstairs seems to run on its own circuit because those all come on and off fine with or without the upstairs, Thanks

 

[Riley]

No unless you have what’s called a one pipe system which I’d say was unlikely you can turn off and on all rads independently. I’d say most likely non functioning trvs

 

[ballvalve]

If you are in a new house it will be a two pipe layout.One pipe is the flow the other is the return.

 

[Aire]

What trvs have been used? Most are bi directional which will work on both the flow or the return but some won't, some also require you to select which side of the system the trv is installed. Can you send a pic of the trv? Also if you can remove the trv head, check that the pin moves freely, it's unlikely 4 trvs have stuck on a new build but worth a try.

 

[Gasinspect]

close down valves on the radiator upstairs that gets hot, see if other radiators begin to heat up. if they do, just crack open the radiator about 1/4 - 1/2 turn. if they don't, then close lockshields on downstairs; again, if then they heat up, open the downstairs lockshields again by 1/4- 1/2 turn and check for even heat after 15 minutes.

 

[townfanjon]

New house , sake !! Not your problem get at the builders /plumbers .

 

[ballvalve]

New house , sake !! Not your problem get at the builders /plumbers .

I don,t think they would come till the new year.( It,s cold)

 

[Jason P]

Thanks this has given me a lot to go by, I will try to get pictures of the TRVs tomorrow. I did not think the downstairs and upstairs would be linked if they are on two different thermostats and worry if I close the lockshield valves downstairs I then unbalance those too and end up with a larger problem.

I spoke to my plumber friend who said to try bleeding them first but they dont even get hot at the bottom so not sure if it is trapped air. I can't see any pins on the TRVs but I can try to get one off tomorrow. Luckily the house is not cold so it isn't urgent. I will try to get on to the builders also, half of the estate is still under construction so they haven't gone far.

 

[Aire]

If it is a stuck pin which is unlikely on a new build, this video will help you

 

[Riley]

Closed lock shields

 

[doitmyself]

Am I right in thinking the water comes from the boiler into the radiator in one pipe, and then out the other into the next radiator, and so on in a long chain. Ie, it doesn't go back to the boiler between radiators or anything like that?

It's more like a ladder. The side rails are the flow and return; the rungs are the radiators. The boiler connects to the side rails at one end.

The amount of water travelling along the flow reduces as a portion passes through each radiator. It increase in the return the nearer it gets to the boiler.

Balancing ensures that each radiator gets its correct share of the flow leaving the boiler.

 

[doitmyself]

It's more like a ladder. The side rails are the flow and return; the rungs are the radiators. The boiler connects to the side rails at one end.

The amount of water travelling along the flow reduces as a portion passes through each radiator. It increase in the return the nearer it gets to the boiler.

Balancing ensures that each radiator gets its correct share of the flow leaving the boiler.

@Azz

Why do you disagree with my description of a two pipe system as a ladder?