P-K SOLIS™
Gas Fired Boiler
Technical Service 1.877.728.5351
Revised: March 15, 2021
Released: March 15, 2021
Patterson-Kelley 2021
All Rights Reserved.
2701000090 P-K SOLIS NURO Installation and
Owners Manual (Rev A).docx
Page 26
P-K SOLIS™ Boiler Model
Flue Vent Category
Maximum Allowable
Pressure Drop
through Combustion
Air Ductwork
Allowable Vent
Pressure
SL-1500, SL-2000
SL-2500, SL-3000
II
0.22” W.C.
-0.01” W.C. to
-0.05” W.C.
SL-1500, SL-2000
SL-2500, SL-3000
IV
0.22” W.C.
+0.01” W.C. to
+0.22” W.C.
NOTE:
If the combustion air intake ductwork and the exhaust vent terminate on the same wall of
the building, they
must
utilize the same type of termination fitting.
NOTE:
Patterson-Kelley recommends including a motorized combustion air damper in each
appliance’s air intake ductwork. Refer to
3.4.5
below for
more information.
Motorized Combustion Air Dampers
Patterson-Kelley recommends, and most
installation codes require, the use of motorized
combustion air dampers with end limit switches
installed in the combustion air intake ductwork
upstream of each appliance. This damper isolates
the combustion air supply when the appliance is in
standby. Once the appliance receives a call for
heat, the motorized combustion air damper opens
and the end limit switch must close before the
appliance can proceed to ignition. Patterson-
Kelley offers motorized combustion air dampers
with built-in end limits switches for sale, which are
summarized in the table below:
Table of Recommended Motorized Combustion Air Dampers
Combustion Air Ductwork
Size
Normally-Closed
Motorized Damper
A
B
C
D
10”
10-0490-6945
10”
10”
13”
3.38”
12”
10-0490-6946
12”
12”
15”
4.38”
These normally-closed motorized combustion air dampers operate on 120 VAC and feature a built in
end limit switch which must be wired to the appliances’ Air Damper Interlock circuit. Upon a call for
heat, the boiler’s Air Damper Relay energizes, which drives the damper motor open. Once the damper
reaches the fully-open position, the end limit switch makes contact and closes the Air Damper Interlock
circuit, allowing the appliance to proceed to ignition. The diagram on the next page shows the wiring
necessary to install the normally-closed motorized damper.
Damper must be in open position when appliance main burner(s) is operating.
Le registre doit être ouvert lorsque le brûleur principal de l'appareil fonctionne
