Installation Instructions 13
059840‐00 Rev. A
Heat‐Timer Corp.
Heating System Sensor Installation
Consider the following when installing the heating system sensor:
• Only use the sensor provided with the control.
• The ideal location for the heating system sensor
is on the furthest radiator in the system. This
radiator is usually the hardest to heat.
• The sensor may be located on the furthest
return riser. However, the sensor MUST be above
the boiler water line (on a dry return). See
“Piping Diagrams” on page 38.
• Strap the heating system sensor to the pipe
using the tie‐wraps provided with the sensor.
Then wrap insulation around the sensor and
pipe to achieve the highest accuracy.
• The sensor wires can be extended up to 500 feet (152.4 meters) using shielded 2‐conductor (#18/2) cable
(Heat Timer p/n 703001‐01).
• Do not connect the shield at the sensor. However, connect the shield at the control. See “Wiring the
Heating System Sensor” on page 18.
CAUTION
Determining the proper location for the heating system sensor is very important. If the heating
system sensor cannot sense the system is full of steam, the EPU‐D will not provide comfortable
heat levels. Be sure the heating system sensor is located on a properly vented pipe that cannot
easily be isolated from the system.
NEVER install the heating system sensor between the condensate receiver and the boiler.
