Enerco HSU 75 User Manual

Page of 36
10
enerco | Compact Unit Heater
operating Instructions and owner’s Manual
5.  Test for spillage at the draft hood relief opening after five 
minutes of main burner operation. Use the flame of a match 
or candle, or smoke from a cigarette, cigar, or pipe.
6.  After it has been determined that each appliance remaining 
connected to the common venting system properly vents 
when tested as outlined above, return doors, windows, 
exhaust fans, fireplace dampers and any other gas-burning 
appliance to their previous condition of use.
7.  If improper venting is observed during any of the above 
tests, the common venting system must be corrected. The 
common venting system should be resized to approach the 
minimum size as determined by using the appropriate tables 
in Appendix G in the current standards of the National Fuel 
Gas Code, ANSI Z223-1 in the U.S.A. and the appropriate 
Category I Natural Gas and Propane appliances venting sizing 
tables in the current standards of the CSA B149.1 Natural Gas 
and Propane Installation Code in Canada.
NOTE local codes may supersede any of the above provisions. 
ELECTRICAL CONNECTIONS
NOTE The MHU/HSU series unit heaters use a direct spark 
ignition system. There is no pilot necessary as the spark lights 
the main burner as the gas valve is turned on. The direct spark 
N
MANUAL  
MAIN SHUT-OFF VALVE  
(FURNISHED BY INSTALLER)
gAS SUppLY CONNECTION
gAS FLOw 
DRIp LEg 
1/8 NpT  
pLUggED TAp 
gROUNDED  
JOINT UNION 
LINE VOLTAgE FIELD wIRINg
UNIT
BLACK
BLACK
wHITE
wHITE
EQUIpMENT 
gROUND
BLACK wIRE wITH wHITE TApE OR  
wHITE wIRE wITHOUT TApE
L1
FIgURE 7
gAS SUppLY TO UNIT HEATER
ISOLATE 
gAS VALVE
MANUAL MAIN SHUT-OFF VALVE 
wILL NOT HOLD NORMAL TEST 
pRESSURE
CAp
UNIT HEATER
FIgURE 8
FIgURE 9
wARNINg
Electric shock hazard. Can cause injury or 
death. Do not use this heater if any part 
has been under water. Immediately call 
a qualified service technician to inspect 
the furnace and to replace any part of 
the control system and any gas control 
which has been under water.
wARNINg
Electric shock hazard. Can cause injury 
or death. Before attempting to perform 
any service or maintenance, turn the 
electrical power to unit OFF at disconnect 
switch(es). Unit may have multiple power 
supplies.
wARNINg
Danger of explosion and fire. Can 
cause injury or product or property 
damage. You must follow these 
instructions exactly.
wARNINg
Danger of explosion. Can cause injury or 
product or property damage. If over-
heating occurs or if gas supply fails to 
shut off, shut off the manual gas valve 
to the appliance before shutting off 
electrical supply.