Normally you will identify this issue if you have a radiator or two that just don’t seem to be heating up at all or maybe it just takes forever to warm up.
Balancing the heating system essentially means – making an adjustment to the waters flow speed and setting flow restrictions to allow hot water to flow around the radiators evenly. Having even heat and flow to all radiators increases the effectiveness and efficiency.
Heating systems vary in sizes, what I mean by that is – systems have different lengths and diameter of pipework both affecting water flow by adding restriction. Another factor is down to the number of radiators on the system, sludge can also be a factor but not a permanent consideration as it can be removed.
Okay well, we’ll start from the beginning, the water is pumped around the house via the systems pump which is generally located in either the boiler itself or external to the boiler in the airing cupboard. When a pump is installed onto a system, it’s never set for the system it’s installed on, therefore adjustments need to be made to balance the system. The pump speed can be adjusted, on domestic pumps normally speed settings 1,2 and 3 – 1 = slow, 3 = fast. Engineers will set the pump speed to ensure we get the required 11-degree difference between the flow and return pipes on the boiler (20-degrees on more modern condensing boilers). Once the speed has been set it’s all about adding restrictions to the radiator valves to help push the flow of water to the last/ furthest radiators on the system. The valves we throttle are the lockshield types, not the thermostatic radiator valves, it needs to be permenant. Once restrictions on the nearest valves have been made and adequate flow has been achieved to all radiators you’re done.
Yeah sure, however – there can be additional issues when you are adjusting – be warned. Adjustment of the lockshield rad valves can cause leaking via the packing glands (easily fixed by plumbers or heating engineers – not so easily fixed by your regular person). Also adjusting the pump speed can lead to pumping over, (water backing up to the feed and expansion tank in the loft) if the system is sludged up. increasing the pump speed can lead to cavitation which will reduce the lifespan of the pump and create unwanted noise and air in the rads.
So in summary – balancing a heating system is a very basic principle, we recommend you to contact a heating engineer to ensure the job is done correctly.