Installation instructions
RTG 199 HE – 6 720 811 617 (2016/01)
18
Appliance condensate drain installation
The appliance comes equipped with an internal condensate drain and
siphon. This drains condensation formed in the secondary heat
exchanger. Piping must be installed under the condensate drain outlet
on the water heater and piped for disposal in accordance with local
codes.
Fig. 19 Appliance drain installation
[1]
Leave minimum ¼ " air gap
[2]
Trap required
[3]
1 ½ " x ½ " PVC reducer
External condensate drain installation
If an external condensate drain (installer supplied) must be installed
(chapter 4.3.2), the following is recommended:
• 1. Install condensate drain on a horizontal section of the exhaust pipe
as close to the heater as possible.
• 2. The condensate must be disposed of according to local codes.
• 3. To install condensate drain in vent system, use PVC 3" X 3" X 1.5"
tee (part# 196278) and reduce for drain connection
Fig. 20 External condensate drain installation
[1]
Condensate drain
[2]
Dispose of condensate in accordance with local codes
[LA] Minimum 4"
4.3.6
Freeze prevention for PVC, CPVC, and ABS systems
In cold climates, components of a tankless water heater can freeze and
burst from negative draft. A leading cause of negative draft is
combustion appliances in the building not being supplied with sufficient
combustion air. A wood stove or furnace can pull its combustion air from
the water heater‘s vent pipe, allowing the cold incoming air to freeze the
cold water in the heat exchanger. Supplying more combustion air for all
combustion appliances is the solution. A HVAC specialist should be
consulted to design solutions for providing more combustion air.
Listed below is an additional measure designed to further limit backdraft
in extreme conditions assuming all other possible causes have been
addressed.
Backdraft reducer
The Heat Fab backdraft reducer (9301BFP) is the preferred option for
limiting backdraft (see fig. 21).
Note: The following solution is available only for 3" diameter
venting.
Fig. 21 Part # 9301BFP
Use materials approved by the authority having
jurisdiction. In the absence of other authority, PVC, and
CPVC pipe must comply with ASTM D1785, F441
orD2665. Cement and primer must comply with ASTM
D2564 or F493. For Canada, use CSA or ULC certified
PVC or CPVC pipe, fittings and cement, see table 5.
PP pipe must be certified under ULC S636.
6720608643-18.1V
