7
Thermostat Sensor
11,900 Ohms @ 70°F, ECO opens @ 201°F Max., ECO close @ 100°F Min.
Thermostat Board
Max temp 180°F, Min temp 91°F, 24VAC, 60Hz max.
Hot Surface Igniter
120VAC, 30-120 ohms @ room temperature.
Flame Sensor Output
Minimum 1 micro amp, Typical range 4 to 7 micro amps.
Temperature Dial
Min. set point 5400-6600 ohms, Max set point 0-50 ohms.
Ignition Module
See “Sequence of Operation, for models starting with CF serial and later”
Gas Valve
Negative regulation, 24 VAC, ½" PSI max., 4.5" W.C. Minimum running inlet.
Transformer
120VAC primary, 24VAC secondary, 40VA.
Vent Safety Switch
Normally closed, opens @ 350°F, manual reset.
Intake Pressure Switch
“CF” serial number or
later
Not required.
Blower
120VAC, 60Hz, .6-1 amps, 6400 RPM.
Exhaust pressure switch
serial numbers prior to
“CF”
24VAC, normally open, closes on pressure increase as follows
Note 1:
+2.58" W.C.
EF(60,100)T199
+1.50" W.C.
EF100T150 (see note 2)
+1.22" W.C.
EF60T150, EF100T250
+2.08" W.C.
EF60T125
+0.55" W.C.
EF100T300 (see note 3)
Note 2: +5.6" W.C. on serials prior to AH5039107
Note 3: +0.8" W.C. on serials prior to AK5288269
Power supply
Dedicated 120 VAC, 60 Hz, 15A, GFI
Approved Gas Type
Natural or Propane. Unit must match gas type supplied.
Venting System
Power vent, balanced direct vent or unbalanced direct vent. See vent tables on page 7
Approved Vent Materials PVC or CPVC
Gas Supply
Minimum 1" NPT for EF100T399, all others ¾" NPT
(schedule 40 black iron pipe recommended)
Minimum Clearance
for Servicing
18" from top, 24" from front, 4" sides and rear.
Maximum Water Supply
Pressure
150 PSI
Gas Pressure (
Nat & L.P.
) 14.0" W.C. maximum static, 4.5" W.C. minimum running (recommend 7.0" W.C. min running)
Combustion Levels
CO2: 10-11%, CO: less then 0.04 percent (400 PPM) air free
Intake Pressure Switch
serial numbers prior to
“CF”
24VAC, normally closed, opens on vacuum increase @ -1.20 W.C.
Blocked Vent Pressure
Switch “CF” serial
number or later
24VAC, normally closed, opens when pressure increases to +2.70 W.C.
7
