LAARS U.H.E. - Service Manual - Manual (Page 6)

LAARS Heating Systems Page 6
6
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 page 9
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.
Blower 120VAC, 60Hz, .6-1 amps, 6400 RPM.
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, CPVC or ABS
Gas Supply
Minimum 1" NPT for UHE100T399, 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
Blocked Vent Pressure
Switch
24VAC, normally closed, opens when pressure increases to +2.70 W.C.