Water Heater Installation Manual
29 Page
Determine the vent diameter (D) and the total vent length based on the number of water heaters installed. The
.
• Total vent length (L)="H"+"W"+
(Number of Elbows X 5)
• Vent diameter="D"
WARNING
• A Non-Return Valve must be installed for each water heater. This prevents the escape of
combustion gas through non-operating appliances.
• For detailed instructions on the common-venting system, refer to the instructions that are
packaged with the vent parts or web site.
*Diameters of pipes are in accordance with Centrotherm's specifications.
**One elbow is equivalent to 5 ft (1.5 m) linear length, and the maximum number of elbows is 5.
NOTICE
• Regarding the clearances
between the exhaust
14 to 16.
• Insert bird screen in elbow
terminations.
Common-venting system
Vent
Diameter*
(D)
Max.
No. of
water
heaters
Max. Vertical and
Horizontal
(Total) Vent Length** (L)
DIP switch settings
4 in 2 25 ft (7.6 m)
240HX3/340HX3 Indoor
OFF
ON
1 2 3 4 5 6 7 8 9 10
No. 6 : ON / No. 7: OFF
540HX3 Indoor
(Upper bank of
DIP switches)
OFF
ON
1 2 3 4 5 6 7 8
No. 3 : ON / No. 4: OFF
5 in
2 50 ft (15.2 m)
3 20 ft (6.1 m)
6 in
2 100 ft (30.5 m)
3 75 ft (22.9 m)
4 50 ft (15.2 m
5 25 ft (7.6 m)
6 20 ft (6.1 m)
8 in
3 100 ft (30.5 m)
4 100 ft (30.5 m)
5 85 ft (25.9 m)
6 65 ft (19.8 m)
7 50 ft (15.2 m)
8 41 ft (12.5 m)
10 in
5 100 ft (30.5 m)
6 100 ft (30.5 m)
7 100 ft (30.5 m)
8 100 ft (30.5 m)
Installaon
Installaon Manual
"H"
Intake
Exhaust
"D"
Elbow terminal
Elbow terminal
"W"
Non-Return Valve
• Adjust the appropriate DIP
switches according to model
as shown in the left table.
DO NOT adjust the other DIP
switches.
(Refer to page 23 for the
location of the DIP switches.)
• Turn off the power supply
to the water heater before
changing the DIP switch set-
tings.
• Failure to observe these
warnings could lead to car-
bon monoxide poisoning or
death.
WARNING
X3™ CARTRIDGE NOT SHOWN.