Product Overview

2
37 1/2 [953 mm]
24 3/4” [628mm]
20 1/4” [516 mm]
18 5/8” [473 mm]
13 1/4” [340 mm]
9 1/4” [235 mm]
3 1/4”
[
83 mm]
1 1/2” NPT Boiler Supply
1” Gas Connection
1 1/2” NPT Boiler Return
4” Combustion Air Inlet
3/4” NPSC Pressure Relief Valve
4” Vent Outlet
17 3/4” [454 mm]
21 1/4” [540 mm]
15 3/8” [390 mm]
14 3/4” [374 mm]
16 3/8” [416 mm]
5
7/8” [150 mm]
1 1/2” NPT Boiler Supply
1 1/2” NPT Boiler Return
1” Gas Connection
4
” Combustion Air Inlet
4
” Vent Outlet
3
/4” NPSC Pressure Relief Valve
Front View
Side View
Pressure Drop Curve with Grundfos Circulators
Model Fuel
Input
Modulation
(MBH)
Thermal
Efficiency
%
Heating
Capacity
MBH
Net
I=B=R
Boiler
Water
Volume (gal)
Supply
Return
Connection
Gas
Connection
Vent/Air
Diameter
Weight
Lbs
PT399
Natural or
Propane Gas
112 - 399 95.1 379 330 7 1 1/2” 1” 4” 200
Delta T GPM
Available System Head (Feet)
UP26-99F UP26-116F UP43/50-75F
20 37.9 --- --- 4.0
30 25.3 10.0 16.0 13.0
40 19.0 16.0 21.0 18.0