quest
quest
1-866-933-7486
Quest Power Electric Heat EHS 31
Pro
Installation, Operation and Maintenance Instructions
6
www.QuestProtect.com
4 Service
WARNING: Servicing the Quest Power Electric Heat EHS 31 Pro, with its high voltage circuitry,
presents a health hazard which could result in death, serious bodily injury, and/or property damage.
Only qualified service people should service this unit.
Do not operate the unit without the front panel in place. High voltage is present, heater burnout may
result.
4.1 Technical Description
The Quest Power Electric Heat EHS 31
Pro
uses a two stage wound nichrome heating element to provide
two heat settings depending on application requirements or available power. One element provides low
power operation and both elements together provide high power operation. The heating elements and
the blower are operated by a 24VAC control circuit and a number of relays and contactors. For safety,
there is an air pressure switch that will shut the heating elements off or prevent the heating elements from
coming on if airflow is restricted at either the inlet or the outlet. An additional safety switch limits the
incoming air temperature to 140°F. This switch shuts off the heating elements and automatically resets
when the temperature falls to 130°F.
4.2 Troubleshooting
NOTE: High Power setting requires an external 50A circuit. Connecting to a 30A circuit with unit set
to High Power will result in an external circuit breaker trip.
Blower not running
1. Unit unplugged, no power to outlet, blown fuse (located behind front cover)
2. Power switch not working or set to “THERMOSTAT” and no thermostat connected, or thermostat not
calling for heat
3. Blower Relay not operating
4. Wiring fault inside device
5. Defective blower or blower capacitor
Blower running but no heat
1. Airflow restricted at inlet or outlet
2. High temperature limit reached (140°F)
3. Heating contactor(s) not operating
4. Wiring fault inside device
5. Defective heating element, pressure switch, or temperature limit switch
