Brochure

66
*For outdoor models, change “ATI” to “ATO”. For propane models, change “N” to “P”
**For propane models, minimum is 13,000
***For propane models, minimum inlet gas pressure is 8.0 in. W.C. and maximum inlet gas
pressure is 14.0 in. W.C.
† Cold climate represents 70°F temperature rise
‡ Warm climate represents 50°F temperature rise
7-7/8" (199 mm)
GAS 5-1/8" (131 mm)
COLD 6-3/4" (172 mm)
HOT 5-1/2" (140 mm)
7-1/2" (189 mm)
GAS 5-7/8" (147 mm)
Condens ate drain port
COLD 5/8" (17 mm)
HOT 4-3/4" (120 mm)
17-5/8" (448 mm)
6-1/4" (159 mm)
5-3/4" (147 mm)
120 VAC 3" (77 mm)
120 VAC 6-7/8" (174 mm)

Drain port
Female
10-3/4" (272mm)
22-1/2" (570 mm)
Condensate drain port
4" (102 mm)
2-5/8" (68 mm)
Exhaust
Intake
Female

7-7/8" (199 mm)
7-1/2" (189 mm)
7" (180 mm)
4" (101 mm)
17-3/4" (450 mm)
HOT 4-3/4" (120 mm)
6-3/4" (170 mm)
COLD 5/8" (17 mm)
GAS 5-3/4" (147 mm)
Condens ate drain port
23-5/8" (600 mm)
2-5/8" (65 mm)
5-3/4" (147 mm)
11-1/4" (285 mm)
1/2 (13 mm)
GAS 5-1/8" (131 mm)
HOT 5-1/2" (140 mm)
COLD 6-3/4" (172 mm)
Condens ate drain port
6-1/4" (159mm)
4" (102 mm)
24-7/8" (631 mm)
120 VAC 3" (77 mm)
Drain port 6" (152 mm)
120 VAC 6-7/8" (174 mm)
INDOOR MODEL
17-5/8" (448 mm)
6-1/4" (159 mm)
COLD 5/8" (17 mm)
120 VAC 3" (77 mm)
HO
T 5-1/2" (140 mm)
HOT 4-3/4" (120 mm)
7-1/2" (189 mm)
Condens ate drain port
GAS 5-1/8" (131 mm)
C
OLD 6-3/4" (172 mm)
7-7/8" (199 mm)
Drain port
7-1/2" (189 mm)
10-3/4" (272 mm)
22-1/2" (570 mm)
120 VAC
Condensate drain port
7-7/8" (199 mm)
Condens ate drain port
11" (281 mm)
1/2" (13 mm)
120 VAC 3" (77 mm)
GAS (131 mm)
HOT (140 mm)
COLD 6-3/4" (172 mm)
Condens ate drain port
COLD 5/8" (17 mm)
GAS 5-3/4" (147 mm)
HOT 4-3/4" (120 mm)
6-3/4" (170 mm)
1-1/2" (37 mm)
11-1/4" (285 mm)
120 VAC 6-1/4" (159 mm)
17-3/4" (450 mm)
7" (180 mm)
23-5/8" (600 mm)
24-7/8" (631 mm)
3-5/8" (92 mm)
4-1/2" (114 mm)
Drain port 6" (152 mm)
OUTDOOR MODEL
INDOOR MODEL
OUTDOOR MODEL
Model
Number*
Type
Gas Consumption Input Inlet Gas Pressure***
Minimum**
(BTU/H)
Maximum
(BTU/H)
Minimum
(in. W.C.)
Maximum
(in. W.C.)
ATI-240H-N
Natural 15,000 160,000 4.0 10.5
ATI-340H-N
Natural 15,000 180,000 4.0 10.5
ATI-540H-N
Natural 15,000 199,000 4.0 10.5
Model
Number*
Energy
Factor
(EF)
Connections
Sizing Chart
(Number of Showers)
Water Gas
Cold
Climate†
Warm
Climate‡
ATI-240H-N
0.95 3/4” NPT 3/4” NPT 2.5 2.5
ATI-340H-N
0.95 3/4” NPT 3/4” NPT 2.5 3.5
ATI-540H-N
0.95 3/4” NPT 3/4” NPT 3 4.5
Model
Number*
Clearances (inches)
Approx Shipping
Weight (lbs)
Top Bottom Side Front
ATI-240H-N
12 12 3 4 62
ATI-340H-N
12 12 3 4 62
ATI-540H-N
12 12 3 4 63