Installation Manual
32
HE Series Infrared Gas Heater Installation and Operation Manual
If at any time the main valve fails to close completely and maintains a flame, the full time flame
sense circuit will detect it and energize the combustion blower. Should the main valve later
close completely removing the flame signal, the combustion blower will power off following the
optional post purge period.
The LED will flash on for 1/4 second, then off for 1/4 second during a fault condition. The pause
between fault codes is 3 seconds.
The Fenwal DSI Control 24 VAC Tube Heater (905000020) is not position sensitive and can be
mounted vertically or horizontally. The case may be mounted on any surface with #6 sheet met-
al screws. All wiring must be done in accordance with local and national electrical code. Refer to
wire diagram page 35 when connecting 905000020 to other components in the burner.
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improp-
er and dangerous operation. A functional checkout of a replacement control is recommended.
Proper location of the electrode assembly is important
for optimum system performance. The electrode assem-
bly should be located so that the spark gap is inside the
flame envelope about 1 inch (2.5 cm) from the base of
the flame at the burner cup.
Electrodes should have a gap spacing of 3/16” (0.188” ±
0.031” or 4.76 mm ± 0.81 mm). If this spacing is not cor-
rect, the assembly must be adjusted or replaced. DO NOT adjust the curved igniter/sensor
prong. Adjust/bend only the ground prong ().
TH Thermostat Input
1/4”
PSW Pressure Switch Input
1/4”
V1 Valve Power (MV)
1/8”
IND
Inducer Blower Output
1/4”
NC
Alarm (Not used)
-
L1 120/240 VAC Input (Hot)
1/4”
24 VAC 24 VAC Supply to Processor
1/4”
V2 Valve (MV)
1/8”
GND Valve & System Ground
1/8”
Spark Spark & Local Flame Sense 1/4”
The Fenwal DSI Control 24 VAC Tube
Heater (905000020) uses voltages of
shock hazard potential. Wiring and initial
operation must be done by a qualified
service technician. The control must be
secured in an area that will experience a
minimum of vibration and remain below the
operating temperature of 160ºF. All
connections should be made with UL
approved 105ºC rated 18 gauge, stranded,
.054 thick insulated wire. Refer to wire
diagram page 35 when connecting the
Fenwal DSI Control 24 VAC Tube Heater
(905000020) to other components in the
burner.