Controls
 
Controls options

There are many ways of controlling the underfloor heating. First of all, almost any boiler can be used for underfloor heating. The most energy efficient system is to use underfloor heating and a condensing boiler. Note, if the underfloor heating system is going to be used with a combination boiler, always check with the boiler manufacturer that the flow can be fitted with a secondary pump.

 
 

Self regulated

Underfloor heating is self regulating if the building is properly insulated. Heat output is dependent on the temperature difference between the floor surface and the room temperature.

 
  For underfloor heating the temperature difference is very small between the floor surface temperature and the air temperature, even a slight change in room temperature significantly alters the temperature difference and the underfloor heating compensates accordingly.
 
 
A practical example would be a dining room. First the dining room is completely empty and then when dinner is served, there are many people in the room giving out heat. The underfloor heating will automatically reduce the heat output and the warm water will simply heat another part of the building.
 
 

Control units

The building can easily be divided into two or three zones. For example a house with concrete floors on the ground floor and timber suspended floors on the first floor, could easily be controlled as two zones.

As generally there are two different floor constructions, the underfloor heating system will need to provide different temperatures and different running times for the floor constructions. This is best achieved with control units
 
 
Beside each manifold, a two part motorised valve, a pump, a mixing valve and a programmable room thermostat is installed. We can provide a pre made control unit for each floor or the control unit can easily be made up by the installer.  
 
Note that the control unit is always required when you mix underfloor heating and radiators in a building.
 
 
Manifolds
 
Return manifolds fitted with two-purpose control/balancing valves.
   
Unit fully assembled, leak-tested and packed
   
Wide range of accessory options.
   
Both trunk ends with flat-sealed joints (nut and gasket) for safe, quick and easy installation.
   
Supply and return manifold are each fitted with a isolation valve and a purge/vent valve assembly.
   
Supply manifold fitted with circuit flow meters for accurate and easy balancing and visual flow indication.
   
Minimised depth dimension allows flush-wall enclosed cabinet mounting.
   
Control valves are designed to accommodate standard actuators.
 
 
Mixing valves
 
High flow, thermostatic blending valve for underfloor heating applications.
 
These valves are suitable for blending the flow and return to achieve a stable system temperature, in systems up to 250 sqm. The thermostatic wax element ensures stable mixed water temperature with quick reaction to supply temperature changes.  
 
 

Individual room controls

The Henco manifolds are supplied with thermostatic options. This means basically that on the flow manifold, actuators can be mounted. The actuators act on an on/off basis and they are connected to an air thermostat in each room. The room thermostats and the actuators are 220-240V.

Henco do not recommend individual controls in the bathrooms as these rooms often require hot water to circulate through the loops to dry the floor. One loop should always be manually regulated, else a bypass is needed on the manifold.

Bathrooms, WC and En-Suites are usually the warmest rooms in a building. The underfloor heating system does not cover a lot of floor area in a bathroom, so the system might not provide enough heat. Therefore it is highly advisable to install a towel rail or a radiator in the bathrooms, to provide extra heat. This can either be connected to your underfloor heating system, hot water system or electrics.
 
 

Filling the underfloor heating system

The system should be filled with water and fully vented of air. This can best be achieved using mains water pressure through the two end caps. All valves should be closed and the flow end cap connected with a hose to mains water, with the return end cap connected to a hose laid to a waste water point.

One by one the flow and the return valves are opened and closed on loops purging them of air. When this is completed and the end caps are closed off, the pumps should be run for five minutes and the air vented again at the end caps until all air is bled from the system