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Wet Underfloor Heating


What floor finish is suitable for wet underfloor heating?

Most floor finishes are suitable for underfloor heating, however, to ensure you get the best output it is recommended that the flooring finish you use has the lowest thermal resistance possible. In the case of carpets, it is recommended the combined rating of the carpet and underlay is less than 1.5 TOG, whereas in regard to wood flooring, it is recommended to use engineered wood rather than solid wood if possible. If there are any doubts about maximum floor temperatures, please check with the flooring manufacturer to ensure that there are no temperature limits on the flooring. If there is a maximum floor temperature limit, the heating can be limited by either adjusting the flow rate or installing a floor sensor.

What output can I expect to get from wet underfloor heating?

Many factors affect the output of the underfloor heating system, ranging from outdoor temperature, required indoor temperature, etc. For a screed system, and based on standard requirements, the heat output will usually be around 70W/m² dependant on flow and return temperatures of 50/40°C, a design room temperature of 20°C, an external temperature of -3°C, and a floor thermal resistance of no more than 0.1W/m²K (1 TOG carpet).

Do I need a floor sensor?

Should floor temperature limits be required, Floor Sensors can be installed with hydronic underfloor heating systems, however, the floor temperature can typically be limited using the flow rate on the manifold. 

My room isn’t warming up even though my thermostat shows it is on?

As wet underfloor heating is typically installed within a screed, the system can take some time to warm up after the initial install, or if it has been off for some time. If this is not the case, you should ensure that the pump and boiler are running. In the event that they are not running, an electrician or plumber would be required to look into this further. If the pump and boiler are running but the room is still not getting warm, then you should check to see if the thermal actuator is opening to allow water to flow into the pipework within the room that requires heating.

What is the maximum loops available on a single manifold?

Most manifold sizes are between 2 – 12 ports. If you require more than 12 loops of pipe, then multiple manifolds will be required.


Electric Underfloor Heating


What floor finish is suitable for an electric underfloor heating system?

Most floor finishes are suitable for use with underfloor heating providing that the floor has been prepared correctly and any manufacturer’s temperature guidelines have been adhered to. With finishes such as wood, laminates and carpets it is essential that the heating mat is completely covered with a latex levelling compound before the specified finish is fitted.

Which type of mat do I need to order – 100W/m², 150W/m² or 200W/m²

  1. The 100W/m² mats are for installation on wooden floors. If the wooden floor is ventilated, it is important to have some form of insulation beneath.
  2. 150W/m² mats are for installation onto concrete based floors.
  3. 200W/m² mats are for installation onto concrete based floors where a more responsive heat is required.

For further information, view our full range of Electric Underfloor Heating Mats.

I have a large floor area that requires two mats, how do I join them together?

The cold tails must be brought out of the floor and have to be connected in parallel. i.e. core colours connected: brown with brown, blue with blue etc.

What is the estimated running cost of an electric underfloor heating system

The running cost of a cable or mat is dependent upon its rating/output and is based on the units of electricity consumed. A unit of electricity is 1000watts (1KW) for 1hour at the unit cost of electricity i.e. 1500w x 1hr x 15p/unit = 22.5p/hr.


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