Reply With QuoteThe system should be balanced.
setting lockshield valves
Should the lockshield valves be fully open or do'es Evohome require a balanced system. My thought is that as not all radiators are operating at the same time fully open valves would reduce strain on the pump. The towel rail is fully open with no thermostat for bypass.
The system should be balanced.
Kind Regards - Dan Robinson (Jennings Heating Ltd)
I have all my lock shields fully open and haven't felt the need to alter them, all rooms warm up as they should. Very often only one or two radiators are in use so i like to keep a good flow. I do have an auto bypass i set to start flowing when only one radiator is on.
The reason I ask is because the sound of water circulation increases as less rooms are being heated, also there is slight increase in energy reqiurements.Originally Posted by robj20
The radiators were balanced for TVR's before the evohome system was installed
I have a more fundamental question. What conditions are you balancing the system for. With Evohome it's a constantly changing circulation path. So I question the traditional wisdom of balancing. Balancing with TRVs is hard enough, with Evohome it adds another layer or hard on top.
When my system was unbalanced with lock valves fully open I had certain radiators that didn’t heat at all when the house was cold and many other radiators were heating. Only later did they get hot. So in that respect I think balancing is essential.
Yes that will happen. But I think in your schedule you must have a lot of radiators coming on together, so in many ways your system is behaving like a non Evohome environment. I bet if you turned optimisation on and when each zone develops a life of their own then the balancing is affected. Hence my genuine question. What situation should you be balancing the system for?
Balancing is so that when all TRV's are fully open the flow resistance to each radiator is roughly equal so they all get a fair share of the water flow. Otherwise a radiator with a short or thick pipe run will get most of the flow and radiators with long or skinny runs will be starved of flow, thus heating slowly, incompletely or in extreme cases barely at all.
Evohome doesn't change this fundamental fact because despite optimal start tending to stagger start times of individual zones there are still situations where all the radiators might try to flow at once - such as a cold start after the heating has been manually turned off and is then turned back on.
In a properly balanced system the hydraulic resistance of each radiator branch will be about the same seen at the point where the flows split up and diverge, if this is the case it doesn't matter what combination of radiators are open or closed - they will all get a fair and balanced share of the flow.
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