2018/19 was our first winter with smart heating controls. This was a positive experience with the benefits coming in two forms. First, we used less gas and our supplier has amended the direct debit to take less money from our account each month and secondly we used our heating system in a different way.
The reduction in gas consumption was around 20%. The savings could have been greater. We currently have a non-modulating boiler which is not fitted with a bypass valve, for this reason the kitchen radiator and bathroom towel rail retain their conventional valves which are always left on to provide a thermal dump when all the motorised valves are closed. This summer the boiler will be replaced and a bypass valve fitted, then two more radiator controls will be added, when this work is complete I expect to get some additional savings. Our ageing dog has arthritis and for his benefit we put his bed in a room with a radiator controller set to 16 deg. C (the boiler also lives in this room so so its always a couple of degrees warmer than the temperature reported by the radiator controller. Without the new controls either he would have been cold or we would have spent a lot of money on gas.
Whilst the financial savings are appreciated, we got better value for the gas we were buying. Because the temperature in each room could be set individually we just heated the rooms in use, this meant we were much more comfortable to turn the heating on. Previously turning the heating on meant heating ten radiators, now, depending on who is home only one to four radiators are on at any given time, which radiators are on depends on the time of day, in the morning it is the bedrooms, during the day it is my work room and the sitting room in the evening. This has made our Edwardian semi, which in every other respect is a thermal disaster, comfortable to live in.
Three years ago our old central heating system had ceased to function, parts of it were thirty to forty years old, the pipes and radiators were clogged and in places blocked with a mess of rust and limescale. Also, the system had grown by additions of pipework that was wrapped around old gas pipes, electrical conduits and some ancient ironwork. Starting again seemed the be best option. I did the work myself, the downside was that whilst I had some workshop training in the distant past, I’m not a qualified/experienced plumber, the upside was that I had the leisure to remove the obstructions which prevented clean pipe runs. I attempted to mitigate my lack of experience by pressure testing the system after making each pipe joint.
Motorised valves were always part of the plan. It seemed a good idea to mount the controllers on the top left of the radiator which placed them at waist height, thus adjustments can be made without having to kneel on the floor. If controls are inaccessible, i.e. at floor level they will be ignored. At any given time it is probable that some radiators will be off, in an attempt ensure adequate circulation, each radiator is served by 22mm flow and return pipes (the tails being 15mm) and the original constant speed pump was replaced with a smarter one.