Installation Guide
www.usaprocom.com
25200068-01A
TROUBLESHOOTING
 WARNING: If you smell gas:
• Shut off gas supply.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone in your 
building.
• Immediately call your gas supplier from a neighbor’s phone. Fol-
low the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the re department.
 WARNING: Only a qualied service technician should service and 
repair heater. Make sure that power is turned off before proceeding. 
Turn off and let cool before servicing.
 CAUTION: Never use a wire, needle, or similar object to clean 
ODS/pilot. This can damage ODS/ pilot unit.
IMPORTANT: Operating heater where impurities in air exist may create odors. Cleaning sup-
plies, paint, paint remover, cigarette smoke, cements and glues, new carpet or textiles, etc., 
create fumes. These fumes may mix with combustion air and create odors.
Note: All troubleshooting items are listed in order of operation.
CHECKING SYSTEM OPERATION
The  millivolt  system  and  individual  compo-
nents may be checked with a millivolt meter 
having  a  0-1000  mV  range.  Conduct  each 
check  shown  in  chart  below  by  connecting 
meter test leads to terminals as indicated.
A. Complete Millivolt System Check
(“A”  Reading  -  Thermostat  contacts 
CLOSED  -  Control  Knob  “ON”  -  Main 
burner should come ON)
a.  If the reading is more than 100 millivolts 
and  the  automatic  valve  still  does  not 
come on, replace the control.
b.  If the closed circuit reading (“A” reading) is 
less than 100 millivolts, determine cause 
for  low  reading,  proceed  to  Section  B 
below.
B. Thermopile Output Reading 
Check
(“B” Reading - Thermostat contacts OPEN- 
Main burner OFF)
1.  Check  gas  pressure  to  the  unit.  If  gas 
pressure is within minimum and maximum 
on  data  plate,  then  check  pilot  voltage, 
325  millivolts  minimum.  If  the  minimum 
millivolt reading is not obtainable, replace 
pilot.
Check Test A B
To Test Complete 
System
Thermopile 
Output
Connect Meter 
Leads to 
Terminals
2 & 3 1 & 2
Thermostat 
Contacts
Closed Open
Meter Reading 
Should Be
Closed Open










