Re: This is just stupid
"mechanical radiator thermostat valves only partly improve on this and need a wasteful fixed bleed radiator to bleed pressure until the central heating water pump stops! "
On my system there is always a bleed path via a radiator in the two rooms with wall thermostats. These are the rooms that need slightly higher temperatures. The radiator circuits only get water if a appropriate thermostat is calling for it. All the other rooms' radiators have mechanical thermostat valves.
However - as a homemade system it is in hindsight a bit too clever by using cascaded signals. One plumber has already claimed that a 3 port motorised valve is EITHER A or B open - my standard Honeywell ones are capable of opening both A and B simultaneously.
My main complaint is that mechanical thermostats seem to have a large hysteresis.
Biting the hand that feeds IT
