1 April 2014
This is a very brief article on how to balance a heating system.
All heating systems and especially two-storey heating systems need to be balanced. By ‘balanced’, we mean that you evenly distribute the flow from the boiler and the pump throughout all the radiators in the house. A quick explanation will show you why we need to do this:
We have the boiler which connects to the pump which in turn leads to a diverting valve. At the diverting valve, one side goes to the hot water cylinders, while the other will go to your radiators.
In a two-storey house, hot water naturally prefers to stay high up in the system. It’s like anything that’s hot (e.g. a Hot Air Balloon) - it will rise up to the top. For that reason, it’s most important that you balance the radiators at the top of the system.
The first radiator in your system (usually upstairs, closest to the boiler and pump) will usually get loads of flow from the boiler and the pump. In an unbalanced system, this water flow will go through the first radiator and be returned back to the boiler without flowing into the rest of the radiators in your system.
What needs to done to avoid this is to go to the lockshield end of the first radiator. The lockshield should be shut completely, then given a quarter or half turn back open again. What you’ll notice then is the radiator might take slightly longer to get warm but will still get to the hot temperature it was achieving before. Importantly however, what you’ve basically done is distributed the flow not just through the first radiator, but also the next radiator along in the system.
What you’d then do is strangle the next radiator down as well, using the same process - shutting down the lockshield fully, then opening it back up by a quarter or half turn and then that radiator would be balanced. You’ll find that this leads the other radiators upstairs and downstairs to get warm.
The other reason it’s important to balance the heating system out is sometimes you find that all the radiators upstairs and downstairs are getting hot, except for one radiator on the extremity of the system. So you’d balance all those radiators out by shutting all the radiators that are getting hot and opening them by half a turn. Give it thirty minutes and you should find that all the rads, including the one that didn’t get hot before, will also get warm.
In practical terms, go to the first radiator in your system and locate the lockshield end. The usual procedure is to turn the lockshield all the way shut (clockwise) and then make a note of what a half a turn would be. Give it a half a turn back open, and that is that radiator balanced. That means that radiator will not take and pinch all the flow from the other radiators on the system yet it will still get hot.
After doing this, you will need to do the same to all your radiators on the system - for best effect do it starting with the closest rad to the boiler and pump and make your way through the system in your home.
(NB - If you have a heated towel rail in your system and it doesn’t have the standard twistable lockshield like standard radiators do, simply pull off the cap and twist shut with a pair of pliers oor a slotted screwdriver.)
Article by Benjamin Clarke