Troubleshooting - heat-timer RSM Installation & Operating Instructions Manual

If there is no display: Check that the 120VAC power is connected to the two orange wires extending from the rear of
the RSM. If power is present, try turning the RSM off and back on again.
If the display reads OPN* : The RSM does not register an outdoor air temperature sensor is connected. Check that
the wires from the outdoor sensor are connected to the front screw terminals marked OUT and COM (see pg. 3). If the
wires are connected properly, they may be broken between the controller and the sensor. If the wires are continuous,
see Checking the Sensors.
If the display reads SHT* : The RSM registers a direct short across the outdoor air temperature sensor. Detach the
outdoor sensor wire from the OUT terminal (see pg. 3). The display should change to read OPN. If it does not, the
RSM may be damaged. If the display does change, check that the wires to the sensor are not shorted together. If the
wires are fine, see Checking the Sensors.
If the display flashes SUP* : The RSM registers a faulty Slab Supply sensor. After SUP the display should flash
either OPN or SHT. OPN indicates the RSM does not register a Slab Supply sensor is connected. Check that the wires
from the Slab Supply sensor are attached to the RSM's terminals SUP and COM (see pg. 3). Also check the wires have
not been broken or damaged. SHT indicates a short across the Slab Supply sensor. Check the wires have not been
shorted together. Finally, go to the section Checking the Sensors next page.
If the display flashes RTN* : The RSM registers a faulty Slab Return sensor. After RET the display should flash either
OPN or SHT. OPN indicates the RSM does not register a Slab Return sensor is connected. Check that the wires from
the Slab Return sensor are attached to the RSM's terminals RET and COM (see pg. 3). Also check the wires have not
been broken or damaged. SHT indicates a short across the Slab Return sensor. Check the wires have not been shorted
together. Finally, go to the section Checking the Sensors pg 8.
* CAUTION: If any of the sensors are reading OPN or SHT, the RSM will shut down the slab heating system.
If the RSM does not activate the heating system: Remove any connections to the Blue output wires. Then take a
wire and short out the two RSM terminals marked EXT and COM (see pg. 3). The red output light should turn on, and
the Blue output wires should be continuous. If the Blue wires are not continuous, the RSM may be damaged. If the
wires are continuous, reconnect the Blue output wires. If the system does not start, the problem is not with the RSM;
check that your heating system is powered and has not been damaged. Finally, if the heating system does start,
remove the jumper between EXT and COM and check that the outdoor air temperature displays below the Outdoor
Cutoff temperature (see pg. 5). If it does not, the RSM will not activate the system. If the RSM is not reading the
correct outdoor temperature, go to Checking the Sensors.
If the RSM does not operate the motorized valve: Check the Target temperature (see pg. 5). If the RSM is not
heating, the display will read OFF. This would happen when the outdoor temperature is above the Outdoor Cutoff or
the Outdoor Cutoff is set to OFF. If the Target temperature is lower than the Slab Supply temperature, then the valve
should be closed**. If the Target temperature is above the Slab Supply temperature, then the motorized valve should
move towards the open position**. If it does not, remove the three connections to the valve motor. When the RSM's
red light flashes the RED and WHITE output wires should be register continuity (the continuity will only last for
several seconds but should occur at least every 30 seconds.) If no continuity is registered, the RSM may be damaged.
Otherwise, check the wiring to the valve (see pg. 4) and the valve itself.
** The valve motor is moved in small increments which may not immediately be noticeable. It may take 20 minutes or
more for the valve to fully open or close.
If snow does not melt or slush is on the slab: Check the values on the Display chart (pg. 5) to make sure all the
parameters are set correctly. If the slab heating system has not been active for at least 24 hours, the slab may not have
gotten up to temperature and the RSM will be controlling to hold the Slab ∆( delta) T or the Supply Limit whichever
results in a lower Slab Supply temperature. If the motorized valve is in the fully open position, the heating system can
not provide enough heat to melt the precipitation. If none of the above are a problem, then adjust the Tune (see pg.
6).

TROUBLESHOOTING

7