Install Instructions

21 of 24 © 2015 Watts Radiant
Troubleshooting Guide
If problems arise with the system or its related electrical components, please consult this
troubleshooting guide. If not qualified to perform electrical work, it is highly recommended a
qualified, licensed electrician be hired.
Problem Possible Cause Solution
Cable resistance
measurement
is outside the
range printed on
the nameplate
label.
An analog meter (using a moving
needle) was used to take the
reading.
Obtain a digital multimeter able to read 0 to
20,000 ohms and remeasure the resistance.
If measurement shows an open
or short circuit, the cable has
been damaged.
Record resistances between all wires and
contact the manufacturer.
If measurement is just a little
low or high, room temperature
has affected the resistance.
Make the room temperature 65°–75°F, or
contact the manufacturer.
The resistance measurement
could be from more than one
cable wired in series, or wired
in parallel. Either will provide
false resistance readings.
Make sure resistance measurements are for only
one cable at a time.
The multimeter may be set to
the wrong scale.
The multi-meter should typically be set to
the 200 ohms (200Ω) scale. For cables with
resistance range higher than 200 ohms on the
nameplate label, set the meter to the 2000 ohm
(2kΩ) scale.
Floor does not
get warm.
Cable has been damaged.
Measure cable resistance. Check for both “open
circuit” and “short circuit” as detailed earlier
in this manual. If damaged, record resistances
between all wires and contact the manufacturer.
GFCI has tripped, indicated by
a light on the control or “GFCI
TRIP”.
Check for loose wire connections. Reset the
GFCI on the control or circuit breaker. If it trips
again, check for a short circuit in the cable
as detailed earlier in this manual. If cable is
damaged, record resistances between all wires
and contact the manufacturer. If cable is not
damaged, replace the GFCI control. Also see
“GFCI conflicts” below.
Incorrect voltage supplied,
or mismatched electrical
components used.
Measure “line” voltage, 120V cable have Yellow
tags marked "120V" and 240V cables have Red
tags marked "240V".
Cables are wired in “series” or
“daisy chained” (end-to-end).
Multiple cables must be connected in “parallel” .
Any electrical troubleshooting work should be performed with the power removed from the
circuit, unless otherwise noted.
Although this troubleshooting guide is provided to assist with problems experienced with a
system, results are never guaranteed. Watts Radiant does not assume any liability or respon-
sibility for damage or injury that may occur from using this guide. If problems with the system
persist, call the manufacturer.