How to Balance Heating System Radiators – Plumbing Tips

Posted by in Plumber Talk, on March 29, 2017


A brief video on how to balance heating system radiators. Includes lockshield positions and TRV’s. Plumbing Tips – diy.

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Today I’m going to tell you about balancing heating systems, why you should do it,
the symptoms that mean you might have to do it, and how to do it. Firstly let’s have a look at the general layout of a heating system.
We’ll have a look at it schematically because that will help you understand why balancing a heating system is so important. Let’s say we have two storeys; Level 1 and gound with the boiler at the bottom.
Coming out of the boiler we have a pump that goes up, through a diverter valve, through some radiators upstairs
and then downstairs with common returns
going back to the boiler. OK? So you’ve got radiators here.
The first reason that a heating system should be balanced
is even if there’s a pump on a heating system
hot water naturally likes to gravitate up
and stay upstairs and then make it’s quick route back to the boiler.
So what you often find is the radiators upstairs are getting loads of heat
and the ones downstairs are still really quite cool
so what you should do is go to the lockshields on the radiators upstairs
close them, then open them at about a quarter of a turn.
You won’t notice any difference in the radiator’s heat capacity or not
but you will notice that more hot water flow is diverted to the radiators downstairs.
Now, you go downstairs, make sure that the radiators are open
and that means the heating system should
be balanced. Another reason you should balance a heating system
is, say, this radiator is getting hot, that one’s getting hot,
and this one’s getting hot, the last radiator on the line isn’t getting so hot
and that’s because these radiators are
effectively pinching the hot water flow delivered by the boiler and the pump.
What you do then is remove the lockshields on these radiators here
strangle those two up there down, shut them,
give them a quarter of a turn. This one here
bring that down, ok, and shut them and give them a quarter of a turn.
We also do a video on why one radiator isn’t getting hot, ‘cos it can
be more than one reason,
not just the fact that the heating system isn’t balanced.
Now that is a brief idea of how you balance a system and why.
Now let’s take a quick look at the lockshield
how to shut it and also to give it a quarter turn nip to make sure that it is all balanced.
So here we are, upstairs, ok. Now the radiators up here get really hot so let’s have a look
at how we’re going to strangle this one down and balance this system.
So here we are with our first upstairs radiator.
There’s four on this system upstairs and do the same thing to each one. Here’s the lockshield end, not the TRV end. Pop the lockshield cap off and close it
by turning it anti clockwise
Once it’s fully closed
just slack it back a quarter of a turn.
Do that to each radiator upstairs and you should find then that the radiator side of the heating system is balanced.
Now let’s look at what we can do to balance out
the hot water coil on your heating cylinder if you have an indirect one. Right, so we’ve
had a look at how to balance the radiators on the heating system.
Now we’re going to have a look at
how to balance the hot water coil on the indirect cylinder.
Alot of houses in the UK have indirect hot water coils on the cylinder.
That means that hot water from the boiler is passed through a coil
in the cylinder and that heats the water up.
Now often these coils are 22mm in pipe size and when the valve opens up
to let hot water through that coil, it pinches loads of heat from the radiators.
Therefore the indirect hot water coil should also be balanced and regulated.
Most plumbers installing an indirect hot water cylinder will put a flow regulating valve
on the return side of the coil Let’s have a look at it.
So, you have your boiler, your pump and your 3-port valve, or if you’ve got an s-plan
it will just be a 2-port valve for each side.
You have all your radiators with their flows and returns. We have the flow coming up here from the boiler, goes through the valve into our hot water coil, in our cylinder
and back out. It is here where we fit our flow regulating valve,
on the return side of the hot water coil. That will go back
into the return side of the boiler.
So, to recap, we have the boiler, the pump, and our diverter valves.
The radiators upstairs have been strangled down and regulated
and the ones downstairs are getting a good flow of hot water.
We’ve also strangled down the return on the indirect hot water cylinder
and the whole heating system now is working properly.
Remember! Balancing a heating system out all you have to do is give each component in the heating system an equal amount of flow

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