Brochure

Specifications
310U: Flow Rate vs. Temperature Rise
100806040200.0
8.0
9.0
7.0
6.0
5.0
1.0
2.0
3.0
4.0
0
Temperature rise (°F)
Flow rate (gpm)
310U: Pressure Loss
Flow Rate (gpm)
8.0 10.06.0402.00.0
Head (ft)
220
200
180
160
140
120
100
80
60
40
20
0
50
40
30
20
10
0
Pressure Loss (psi)
60
70
80
90
100
Dimensions
Indoor and Outdoor Installation Options
Power Vent or Power Direct Vent Design
Ultra-Low NOx Emissions
4” Category III Vent
Gas convertible from natural gas to propane using
the included conversion kit
Flow Rate up to 8 GPM
• Values based on factory testing. 0.4 GPM required for
continuous fire after initial ignition
Water Pressure: 15-150 psi
• Pressure Only Relief Valve Requires (Min 190,000 btu/h,
150 psi).
• 40 psi or above recommended for max. flow
Warranty
• 15-year limited warranty on heat exchanger in residential
applications.
• 5-year limited warranty on heat exchanger in commercial
applications.
• 5-year warranty on all parts.
• Refer to hotwater.com for further warranty details
120 VAC 1-5/8" (40 mm)
COLD 1-5/8" (41 mm)
GAS 5" (127 mm)
HOT 4-5/8" (116 mm)
20-1/2" (520 mm)
1" (26 mm)
13-3/4" (350 mm)
10" (254 mm)
1-3/4" (45 mm) 1-3/4" (45 mm)
21-1/2" (545 mm)
1-3/8" (36 mm)
4-3/8" (113mm)
19-3/8" (493 mm)
120 VAC 3" (75 mm)
GAS 5-1/4" (135 mm)
HOT 6" (153 mm)
COLD 6" (153 mm)
2-1/4" (58 mm)
3-5/8"(93 mm)
10" (256 mm)
1-7/8" (47 mm)
HOT 5"(127mm)
120VAC 1-7/8" (49 mm)
GAS 4-1/4" (109 mm)
COLD 5" (127 mm)
5-1/8" (130 mm)
13-1/8" (334 mm)
4-3/8" (113 mm)
AT-KJr3U/K5U/D3U-IN
120 VAC 1-5/8" (40 mm)
COLD 1-5/8" (41 mm)
GAS 5" (127 mm)
HOT 4-5/8" (116 mm)
20-1/2" (520 mm)
1" (26 mm)
13-3/4" (350 mm)
10" (254 mm)
1-3/4" (45 mm) 1-3/4" (45 mm)
21-1/2" (545 mm)
1-3/8" (36 mm)
4-3/8" (113mm)
19-3/8" (493 mm)
120 VAC 3" (75 mm)
GAS 5-1/4" (135 mm)
HOT 6" (153 mm)
COLD 6" (153 mm)
2-1/4" (58 mm)
3-5/8"(93 mm)
10" (256 mm)
1-7/8" (47 mm)
HOT 5"(127mm)
120VAC 1-7/8" (49 mm)
GAS 4-1/4" (109 mm)
COLD 5" (127 mm)
5-1/8" (130 mm)
13-1/8" (334 mm)
4-3/8" (113 mm)
AT-KJr3U/K5U/D3U-IN
26