Struggling to balance radiators

[gerbils]

Since we had a new boiler installed I am struggling to balance the radiators - they will be fine for a few days or even weeks but eventually go very tepid.

Because they are tepid It's difficult to work out which order they run in.

I have just brought some digital thermometer clips and plan on trying to get them all with a 12 degree diference but unsure which side I should adjust as on many radiators the screw looks the same - only one is usually covered with an old school +/- nob - I believe that is a manual valve and the lockshiled is the opposite side to that?

I thought the lock shield was the outlet and would be the cooler side, but on some radiators this seems to fill the radiator and is generally hotter!

So confused becasue all the YouTube videos are based on rads with thermostatic valves and we have none!

 

[JohnD]

Balance using the lockshield.

Post photos of both valve types please.

The idea of the lockshield is that the plastic knob is just a cover and does not adjust the valve. You take it off to turn the spindle. So nobody fiddling with the knob later will upset your balancing.

 

[gerbils]

All of them have these as both sides - expect 1 radiator which has a flat type screw.



Half have one side like this (which is the same as above underneath)



Some have a white cap over one side which I assume is the lock shield but who knows as underneath they look the same.

one or two have drainage pipes coming off them.

 

[JohnD]

The valves themselves are the same. It is only the absence of a knob that makes it a lockshield.

 

[gerbils]

The valves themselves are the same. It is only the absence of a knob that makes it a lockshield.

The ones without a knob appear to be the ones that control flow into the radiator.

I thought the lockshield was on the return…

In this case which ones do I open fully and which do I open a half turn etc ?

 

[JohnD]

Doesn't matter. The knob is the only difference on yours. You can move it if you want.

If you have TRVs, it is an advantage to put them on the flow side to prevent chatter. But you haven't.

 

[Madrab]

Doesn't matter whish valve you use to balance if you only have turn down valves, as long as once it's set it isn't changed, hence the reason that the lockshields are used.

It also doesn't really matter which is flow or return as both restrict the water flow in and therefore out of the rad.

The valves that have the turn head on them leave fully open and turn the lockshields off on all the rads, then start blancing from there.

 

[gerbils]

I am assuming on our rads the

Doesn't matter whish valve you use to balance if you only have turn down valves, as long as once it's set it isn't changed, hence the reason that the lockshields are used.

It also doesn't really matter which is flow or return as both restrict the water flow in and therefore out of the rad.

The valves that have the turn head on them leave fully open and turn the lockshields off on all the rads, then start blancing from there.

On our rads, the one with the turn head appears to dictate the flow out of the radiator.

I have closed both valves off, and if I open the one with the turn head fully open, nothing happens.

If I turn the valve on the other side, I can hear water rushing into the radiator.

However, the opposite side of the radiator, the one with the turn valve heats up first - why is that?

 

[denso13]

why is that?

It'll be the flow.

 

[gerbils]

It'll be the flow.

That's what I thought - but if that's true why doesn't the radiator heat up with the flow fully open and lock shield closed? Is this due to air?

In my mind the radiator would fill up with hot water but just not go anywhere after that.

 

[denso13]

I have closed both valves off,

Open one fully and the lockshield only a quarter open. See if that one heats then move on.

 

[denso13]

but if that's true why doesn't the radiator heat up with flow fully open and lock shield closed

There cannot be any flow with one closed. It will not heat at all.

 

[gerbils]

There cannot be any flow with one closed. It will not heat at all.

Okay thanks!

 

[Mister Banks]

That's what I thought - but if that's true why doesn't the radiator heat up with the flow fully open and lock shield closed? Is this due to air?

In my mind the radiator would fill up with hot water but just not go anywhere after that.

The radiator is already full of water so the hot water has no where to go.

 

[Madrab]

If I turn the valve on the other side, I can hear water rushing into the radiator.

You can't hear water rushing into the rad, just like you cant hear water rushing out the rad, all you are hearing is water moving through a valve, the direction of the flow would be hard to gauge just by the sound.

The only way hot water can get into the radiator is if there is a flow out, thereby creating circulation, that's how the CH system works. The circulator (pump) creates water flow, that water flow heads into the boiler's heat exchanger, is heated and then flows out and along the flow pipe of the 2 pipe system, then it enters the rad through an open valve, circulates around and the out the open return valve and that then heads back the boiler after losing it's heat in the rad. Without a rad with 2 open valves the water cannot move (closed head) unless there is a bypass.