NRP620-9 OMEPAPV20161017 (ENGLISH) REV 1
Page 15 of 42
Barometric Draft Control
**IMPORTANT**
The following procedure for measuring and setting the proper chimney draft is probably the most
important installation procedure to follow for the proper operation of the A-Maize-Ing Heat® furnace.
The A-Maize-Ing Heat® furnace requires 0.02 – 0.04 inches water column draft (chimney draft) on low
fire, to assure proper operation. Low fire mode is when the thermostat is satisfied and fuel is not being
augured into the burner. When the chimney draft is too high, burner fire may go out. If the chimney
draft is too low, smoke may back up in the furnace and storage bin, causing a possible hazard.
The supplied barometric regulator should be installed in the flue (as per the enclosed instructions) to
properly regulate 0.02 – 0.04 inches water column draft. The counter weight setting on the barometric
regulator regulates this setting. If this setting is exceeded it could cause a solid fuel fire to burn out of
control.
The chimney draft measured at the barometric regulator should never exceed 0.04 inches water
column. On extremely tall chimneys or on chimneys larger than 6” diameter, it may be necessary to
install a second barometric regulator or to reduce the outlet opening on the chimney to approximately
28 square inches or both to maintain the required 0.02 – 0.04 inches water column draft.
Refer to the installation and adjustment instructions included with the barometric regulator (Part
BDC1A01A).