Install Instructions

33 of 36 © 2016 Watts Water Technologies
If not qualified to perform electrical installations, it is strongly recommended that a qualified,
licensed electrician be hired to install the heating cables and related electrical components.
If problems with the system arise, please consult the troubleshooting guide below.
Problem Possible Cause Solution
Cable resistance
measurement is
outside the range
printed on the
nameplate label.
An analog ohmmeter (using a
moving needle) was used to take
the reading.
Obtain a digital ohmmeter 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 (18º-24ºC),
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 multi-meter may be set to the
wrong scale.
The ohmmeter should typically be set to the 200
(200Ω) scale. For heating wire 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, 120 VAC cables have black
and white leads. 240 VAC cables have black and
blue leads.
Uninsulated concrete slab floor.
Surface temperatures rise slowly on an uninsulated
slab and heat is lost to the ground below. If, after
5 to 8 hours of heating, the floor is not warmer to
the touch, check for cable damage (see “Cable has
been damaged” above). Measure “load” voltage/
amperage to cable.
Cables are wired in “series” or
“daisy chained” (end-to-end).
Multiple cables must be connected in “parallel” (or
black-to-black, white-to-white).
Troubleshooting Guide
Any electrical troubleshooting work should be performed with the power removed from
the circuit, unless otherwise noted.