Testing and Commissioning your Electric Underfloor Heating

February 19, 2019 Katie

It is vital that you complete your testing and commissioning in order to validate the warranty of your underfloor heating.

The warranty for many reputable underfloor heating products is usually quite high, with most offering 10 years, 20 years or even a life-time warranty.

A warranty is only valid providing the system has been installed in accordance with the manufacturers installation guidelines. All minor electrical works are to be carried out by an IEE 17th Edition qualified electrician, in accordance with Part P Building Regulations 2005.

The following tests will need to be carried out with your digital multimeter and floor sensor:

Heating Cable Resistance Test

This test is carried out to prove continuity of the heating element. A low resistance ohm meter should be used (ie Multimeter on ohm setting), connect your meter on to the brown and blue mains lead and confirm resistance value matches that quoted on your specification label on the cable cold lead joint.

Floor Sensor Resistance Test

See Heating Cable Resistance Test above and repeat with floor sensor cable.

Insulation Resistance Test

This test is performed to measure the insulation resistance between conductors and ensures the cable insulation is not damaged. A low resistance reading indicates a damaged cable and must be repaired or replaced. The insulation resistance tester should be connected between the conductors (blue and brown cables) and the earth (yellow/green cable). The meter should record a high resistance value e.g. above 100 Meg ohms.

The required tests should be completed at 3 stages when laying your underfloor heating and recorded on your commissioning sheet which is supplied with your kit.