Submittal Sheet
Page 9
ADJUSTMENTS 
PRESSURE SWITCH ADJUSTMENTS 
With the venter air flow set and the appliance operating at 
the best operating efficiency, adjust the pressure switch by 
rotating the adjustment screw clockwise until the burner 
shuts off, then rotate the adjustment screw 
counterclockwise until the burner fires. Rotate the 
adjustment screw an additional 1/4 to 1/2 turn 
counterclockwise to ensure proper switch setting. (See 
Figure 7) 
P
OST PURGE TIMING ADJUSTMENT 
To adjust the post purge time, rotate the timer adjustment 
on the timer clockwise to increase the operation time. To 
decrease the operation time, rotate the timer adjustment 
counterclockwise. (See Figure 8) Typical post purge 
time should be between 3 to 5 minutes. If running 
burner simultaneous with venter, 1-3 minutes is 
suggested. 
S
YSTEM CONTROL CHECK OUT PROCEDURES 
1.  Adjust the thermostat to call for heat and observe 
the power venting system for proper operation 
sequence (Repeat if necessary). 
a.  Thermostat calls for heat. 
b.  Relay is energized and venter motor starts. 
c.  Pressure switch closes and burner starts. 
The LED light indicates power to T3. When the 
pressure switch closes with a call for heat, the 
LED light will come on. This indicates that the 
burner should be in a burn cycle. (See Figure 
8) 
d.  Thermostat is satisfied, burner stops and venter 
motor should operate for the set post purge time.  
The LED should not be on during the post purge. 
2.  While system is operating, disconnect power to 
the venter motor. This should open the pressure 
switch contacts and stop burner operation. 
3.  (If WMO-1 switch is installed) Allow vent system to cool. Disconnect the vent pipe between the venter inlet 
and the appliance outlet. Block the vent pipe with a noncombustible material. Activate the heating system 
with the main burner operating. Allow approximately 2 minutes or less for the secondary safety switch to 
deactivate the burner. Reset safety switch after waiting 15 minutes for WMO-1 to cool down and repeat. 
YEARLY MAINTENANCE PROCEDURE FOR POWER VENTER
1.  Motor: Inspect motor once a year; the motor should rotate freely. 
2.  Wheel: Inspect venter wheel annually, for oil fired heating systems, clear any soot, ash or coating, which 
inhibits either rotation or air flow. Remove all foreign material before operating. 
3.  Vent System: Inspect all vent pipe connections annually for looseness and for evidence of flue gas leakage. 
Seal or tighten pipe connections if necessary. 
4.   Lubricate motor with SWG Superlube with 6 drops in each oil port hole annually. 
Figure 8
Figure 7
Post Purge 
A
djustment 
Location 
LED 
light 










