Water Underfloor Heating Controls Requirements with Heat Pumps and Condensing Boilers
It is recommended that every standard wet underfloor heating system has individual room controls. Each room should be fitted with programmable digital room thermostats. Wet rooms, such as bathrooms and en-suites, can be together with bedrooms.
Only a one large room system should be fitted with one room thermostat, a large Kitchen for example.
Some heat pumps work with a minimum flow rate and therefore manufacturers will recommend that no individual room controls are fitted. This is not good practice and is not recommended by the UHMA (Underfloor Heating Manufacturers Association).
A buffer tank must be fitted when installing a heat pump with underfloor heating and individual room controls are always recommended.
For a normal condensing boiler, it is always recommended to use two-port valves to control the heating and the hot water system, i.e. a S-Plan system. Do not use a Y-Plan system as the heating system will not work correctly with a three-port valve.
If using a solid fuel burner, never connect the heating system directly to the underfloor heating system as flow temperature will be too high. The heat from the solid fuel system must first be sent to a thermal store and from there the heat can be pumped to the underfloor heating system.
Each manifold will have it’s own mixing valve to control the water temperature to each manifold. Also, by the manifold a pump is fitted to pump the water through the loops.