Greenheck Fan Make-Up Air Unit VSU - Manual (Page 7)

7 Model VSU Make-Up Air
® ® ® ® ®
Vent Line Solenoid
To Burner
Vent Line
To Outdoors
From Supply
Safety
Shut-off Valves
Optional Vent Line
WARNING
NEVER test for a gas leak with an open flame.
NOTE
The factory piping has been checked for leaks, but
should be rechecked due to shipping and installation.
4. Pipe the Optional Vent Line
If an optional vent line is located between the safety
shutoff valves it must be piped to the outdoors.
WARNING
Reference the National Fuel Gas Code for additional
vent line requirements.
5. Test the System for Leaks
Check both the supply lines and the factory piping for
leaks. Apply a soap and water solution to all piping
and watch for bubbling which indicates a leak.