Wired Thermostatic Radiator Valves are always the best and most reliable TRV option. Each wired TRV requires a thin 2-core, bell-wire type cable to be run between the radiator and HeatingSave controller. This is often a simple retrofit if you have false ceilings and an obvious choice for new or refurbished buildings. Wired TRVs are low voltage, requiring only 24 volts DC, and they draw very little current. If you have several radiators, then you can wire these in parallel to one HeatingSave relay.
Thermostatic Radiator Valves can be used to split rooms or areas into individual heating zones, meaning that heating can be turned on in occupied areas and turned off in unoccupied areas.
Wired TRVs need only one relay for each radiator or group of radiators. Additional T3516 sub-units can be connected to every T3520 controller, adding 8 off relays, 8 off digital inputs for PIR's or switches, 8 analogue inputs for temperature and light sensors + two connections for smart card readers for access control OR inexpensive attendance monitoring. Your whole system can be multi-site and multi-building with as many T3520 controllers as needed.
