A programmer controls when heating can run. A thermostat responds to temperature and can stop the call for heat at its set point.
Managing Heating Zones, Temperatures and Flow
A heating system needs a way to decide when heat is called for and where the water should flow. MacBlair’s controls and valves range includes room and cylinder thermostats, timers, programmers, two-port motorised valves and radiator valves. The listed products cover both electrical control and the mechanical parts that act on those signals.
A programmer sets operating times, while a thermostat responds to temperature. Two-port valves can open or close a heating or hot-water zone; radiator valves give control at individual emitters. Check the wiring arrangement and whether the existing boiler needs a specific compatible controller before replacing a part.
Physical details matter just as much as the control function. The visible valves include 22mm and 28mm motorised models, plus angled and straight radiator options. Match connection size and flow direction to the existing pipework and fittings. A heating engineer can confirm the right configuration, especially where a replacement affects several zones or a heated towel rail.
Control Valves FAQ's
It opens or closes one hot-water or heating zone when the connected controls call for heat.
Check the existing pipe size and the system design. The replacement also needs compatible controls and flow characteristics.
Some listed TRV heads are separate replacements, but the head must fit the existing valve body.
Yes. The thermostat, programmer, wiring or actuator can each cause similar symptoms.