PB-1525 Wood Pellet Burner System: Installation and Operation Manual
Rev 1.0, OCTOBER 2011
Page 18 of 67
Measuring Chimney Draft
The PB-1525 requires a negative draft chimney installation. Draft must be
measured with a proper draft gauge.
Prior to measuring draft, be sure that the boiler/furnace is air tight and all
leak points are sealed. Air leaks can give faulty results and can cause
problems when operating the PB-1525. The draft measurement is to be
taken in the firebox of the boiler or furnace as an “Over Fire”
measurement.
Draft should be between -0.03 in-H
2
O to -0.10 in-H
2
O. If the Draft is more
than -0.10 in-H
2
O, or likely to exceed -0.10 in-H
2
O a draft regulator
(barometric damper) is required for use.
The use of a draft regulator (barometric damper) is recommended for use
in every installation due to the potential for high winds and resulting high
draft. If the system is exposed to temporary draft in excess of -0.10 in-H
2
O
a misfire can occur thereby shutting down the system.
WARNING!
Improper draft can lead to potentially hazardous
conditions. Chimney draft must be within system
limitations at all time.
The boiler and chimney must be kept clean to maintain
proper draft.
If draft is less an -0.03 in-H
2
O , a forced draft blower, or draft inducer, can
be installed to create proper draft. Install per manufacturer’s
recommendation and guidelines. Be sure that any device used is listed
for use with solid fuels.
Following initial installation of the PB-1525, proper cleanout maintenance
in the boiler/furnace as well as the chimney is a necessity. Fly ash, clinkers
and buildup within the chimney and boiler/furnace can cause blockage
and improper operational draft. Refer to Chapter Four: Maintenance, for
information on cleanout.
