LAARS U.H.E. - Service Manual - Manual (Page 43)

U.H.E Service Manual Page 43
Product Handling - Carefully uncrate the heater. Move in place with a hand truck (Do not use the
venting pipes for handles).
Electrical Requirements - Make sure there is 120 volts line voltage. Line voltage must be properly
polarized. Adequate ground supplied to the heater.
Venting Requirements - All venting must stay within the required lengths and diameter (see table
below). Proper support of the venting pipe is a MUST (every 5ft vertical and 3ft horizontal).
Termination must be located to prevent re-circulation of flue gases. Medium to long sweep 90°
elbows or straight exhaust terminal coupling recommended.
Gas Requirements - Gas piping sized adequately, ¾" or larger to heater or 1" or larger for
UHE100T399 models. Install a properly sized regulator (if unknown, assure an adequate volume of
gas is available). 7" W.C. is required when the unit is running. Gas pressure must stay below 14"
W.C. static pressure. Pressure drops between static pressure and operating flow should be less
than 3" W.C.
Condensate Requirements - Condensate line needs to slope to a drain at a minimum of ¼" per
foot. Make sure the condensate line does not have the potential to freeze. If using more than one
heater and using a common condensate line, make sure the condensate line is properly sized.
Service/Mechanical Room - Provide adequate space for servicing heater. Leave room to get to the
top and bottom pressure switches as well as enough overhead room to remove the anode rods for
servicing (18" min.).
Vent tables
Note: each 3" & 4" 90° Elbow is equivalent to 5 feet of
straight pipe.
Note: each 3" & 4" 45° Elbow is equivalent to 2.5 feet of
straight pipe.
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Unbalanced Direct Vent Systems
Air intake CAN NOT exceed exhaust
by more than 30 feet
Power Vented Systems
PVC, CPVC
Total length of exhaust piping must not exceed
“Maximum Vent Length”
Shown below
Maximum Vent Length (feet)
Model Number 3"
UHE60T125, UHE100T150 120'
UHE60T150, UHE100T199
UHE60T199
UHE100T300
100'
80'
60'
4"
170'
150'
130'
110'
UHE100T399 50' 100'
Balanced Direct Vent Systems
PVC, CPVC
Total length of intake piping and exhaust piping
added together must not exceed “Maximum
Combined Length” Shown below
Maximum Combined Length (feet)
Model Number 3"
UHE60T125, UHE100T150 120'
UHE60T150, UHE100T199
UHE100T250
UHE100T300
100'
80'
60'
4"
170'
150'
130'
110'
UHE100T399 50' 100'
UHE60T199 80' 130'
UHE100T250 80' 130'