
NG & LPG Heaters • Rev. 4/13/2016
CAUTION: If the heater is left unused for extended periods during sub-zero weather, a column
of freezing air will build up in the venting system. If the building has a negative pressure
condition, some of the freezing air will be drawn over the draft hood, spilling onto the heating
coil which will eventually cause it to freeze and rupture. Have an installer ensure that correct
draft conditions are maintained to prevent this costly occurrence.
LOCATED IN CONFINED SPACE
The confined space should have 2 permanent openings: one near the top and one near the bottom
of the enclosed area. The openings need to be a minimum of one square inch per 1000 BTU’s of
the total input rating of all units in the enclosed area. The openings shall grant free access to the
interior with sufficient passage from the outside. Consult a certified gas installer on location and
installation.
WARNING: If you do not follow these instructions exactly, a fire or explosion may result,
causing property damage, personal injury, or loss of life. Do not tamper with factory installed
controls.
PORTABLE PROPANE APPLICATIONS
An optional rain cap can be furnished to the flue outlet.
FREE AIR FOR COMBUSTION AND VENTING
If the unit is installed in an equipment room or other enclosure, care must be taken to supply
sufficient free air for combustion and ventilation. Observe CAN1 B49.1 and 2 InstallationCode
Requirements. Care should be taken to keep the base of the unit clear of trash or any object that
could interfere with combustion air to the burner. The installer will know how and where to
place a supply air duct, ensuring that the opening will not promote drafts that may blow out the
pilot. Keep area around machine clear to ensure air can get to the burner.
COMBUSTION AIR SUPPLY
Natural Gas or Propane is consumed; therefore, air is required for combustion, for draft hood
dilution, and for ventilation.
BASIC CONTROLS
The water heaters are equipped with automatic gas valves that have an electronic control with an
ignitor and a thermostat. A high temperature limit protects the system against excessive outlet
water temperature. A pressure switch prevents burner operation without water flow. A burner
“On-Off” switch is provided for manual control.