When I moved into this house the central heating was a mess, two pumps one for main house and one for flat under house, I think who ever throw together the system, thought they could control if house or flat was heated by selecting pump, however selecting one pump resulted in the direction of flow reversing in the system connected to other pump.
I am not good at plumbing so I got some one in, and they fitted two motorised valves which I wanted, but left it with two pumps, which since motorised valves only have one V3 micro switch means I have needed relays so each pump is independent but boiler fires with either pump.
It would have been easier with a single pump.
But it seems the heating engineer considered it needed two, and I bowed to his superior knowledge.
However my point is the problem getting some one who understands the system once one tries some thing out of the normal for that type of installation. All is good until some thing goes wrong, then people are left scratching their heads trying to work out what is should do.
Even a reasonable standard central heating installation it seems are beyond the knowledge of many, I have been unable to understand why systems have motorised valves splitting it into zones, and TRV's? There will be the special like this house with flat and main house, where I want to be able to turn off whole flat, but in the main we have a house with a selection of rooms each with different requirements for heating, be it children going to bed earlier, or using room for doing home work, or bedrooms being used as an office or craft room, it is very unlikely all rooms upstairs and all rooms down stairs can be controlled together. Likely dinning room not used after 8 pm, but living room wanted until 11 pm so makes more sense to use programmable TRV heads, specially when they only cost me £15 each in 2019.
But switching on a TRV is different to switching off. No need for a TRV to be linked to turn off earlier to room with wall thermostat, but there is if the room wants to turn on when room with wall thermostat has not had a temperature change.
So without linking it needs some thought, turn wall thermostat down a degree an hour before another room is required, then back up as the room TRV opens. To ensure boiler runs. This way one can get rooms to heat up at times set, but far easier to do with linked TRV's.
It only needs a little thought, and one can set a sequence so rooms are heated in the order they are used, a 10 minute delay is enough to ensure one radiator is stinking hot before another starts to heat, but a 20 minute delay could cause the boiler to switch off. Or with a modulating type turn down the output. And for it all to work, lock shield valves also need setting, and radiator sizes selected big enough for the reheat. A radiator designed to maintain the room temperature is much smaller that one to reheat the room.
So we look at a boiler at 28 kW, and we count up the radiators, 4, 4, 3, 2, 3, 3, 3, KW through the house, simple maths 22 kW of radiators connected to a 28 kW boiler is the wrong way around, radiators should be twice the size of boiler to have any rooms not heated as selected times. It seems our homes were not designed, they were just thrown together, we see a street of houses with the same design either side of the street, how can this be right? Sun shines from the south, so either side of street needs a different design to match direction of sun, and roof should have one part sloping to catch the sun, I know solar panels can work East/West, but should not all new house roofs be designed to take solar panels including the slope matching winter sun.
