Monessen Hearth PARLOR VENT-FREE PL20 User Manual
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Parlor Vent Free Fireplace
CHECk SYSTEM OPERATION
The millivolt system and individual components may be checked with a millivolt meter having
a 0-1000 mV range. Conduct each check shown in chart below by connection meter test leads
to terminals as indicated.
A. COMPLETE MILLIVOLT SYSTEM CHECk
(“A” Reading - Thermostat contacts CLOSED - Control knob “ON” - Main burner
should turn 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, 35 millivolts minimum. If the minimum millivolt reading is
not obtainable, replace pilot.
Connect Meter
Switch or
Meter
Check
To
Leads to
Thermostat
Reading
Test
Test
Terminals
Contacts
Should Be
A
Complete
& 3
Closed
Closed
System
B
Thermopile
1 &
Open
Open
ELECTRICAL INSTALLATION