Patterson-Kelley Thermific Installation & Owner's Manual page 21

®
Thermific Gas-Fired Boiler
On/Off
(700, 1000, 1200 Series only)
Setscrew
Air Shutter
Increase
Loosen the setscrew on the air shutter and open or
close the shutter as required to adjust the air flow. Re-
tighten the holding screw after adjustment.
Alternate On/Off
(1500, 1700, 2000 Series)
Alternate Air Flow Adjustment - On/Off
The setscrews on the definite stop bracket hold the air
damper in place. Loosen the nuts and rotate the
screws as required for proper air flow. When the defi-
nite stop is in the desired position, tighten the nut on
each screw. Both setscrews must be touching the
definite stop before they are locked in place. Do not
adjust any other part of this mechanism.
Decrease
Air Flow Adjustment - On/Off
Damper Bracket
Definite
Stop
Setscrew
Lo-Hi-Lo
This is a two stage firing arrangement with the me-
chanical action provided by the two stage gas valve
actuator. The boiler is factory fire-tested and adjusted
for two firing rates: Hi fire (100% of rated input) and
Lo fire (60% of rated input).
Fuel adjustments for proper fuel input are made first at
the gas pressure regulator with the valve actuator in
the Hi fire position. Lo fire fuel adjustments are made
second, with the valve actuator in the Lo fire position.
The low fire cam (internal to the valve actuator) is in-
creased or decreased to obtain proper fuel input.
Lo-fire
Setscrew
Linkage
Air adjustments corresponding to both Hi fire and Lo
fire are required at the same time as corresponding fuel
adjustments. Adjust Hi fire air first, and Lo fire air
second. The valve actuator utilizes a damper output
shaft that is connected to the assembly shown in the
photo via the damper rod.
There are two methods of adjusting Hi fire:
•
Grasp the damper rod with pliers, loosen the two
allen screws (1/16") on damper rod, and make
very small adjustment to shaft. Retighten the allen
screws. A slot in the end of the damper rod indi-
cates the damper position.
•
Or, adjust Hi fire air with the valve actuator in the
Hi position, unlock and loosen the right hand
screw on the definite stop bracket, and utilize the
swivels on the crank arm assemblies located at ei-
Page 17
Installation
Damper Rod
Damper Bracket
Hi-fire Stop
Definite Stop
Air Flow Adjustment - Lo-Hi-Lo