Installation Manual

H-Series Demand Duo™ 2 Installation and Operation Manual 29
Condensate can form in the vent of high
efficiency, direct vent tankless water heaters.
Without proper drainage, condensate will damage
the heat exchanger located inside the tankless
water heater.
When connecting the condensate drain line,
follow these guidelines:
• Use only corrosion-resistant materials for the
condensate drain lines, such as PVC pipe or
plastic hose.
• The condensate drain line should be as short
as possible and have a downward pitch.
• The end of the condensate drain line should
be open to the atmosphere. The end should
not be under water or other substances.
WARNING
EXTERNAL TRAP
NOT REQUIRED
• DO NOT connect the condensate drain line
directly to the rain sewer.
• DO NOT connect the condensate drain line
with an air conditioning evaporator coil drain.
• DO NOT pipe condensate drain, temperature-
pressure relief valve, and/or pressure relief
valve together into a common pipe.
• Water heaters have an integrated condensate
trap. DO NOT install an external condensate
trap.
To connect the condensate line:
Place the condensate drain line (1/2 in. clear
vinyl tubing) towards the drain.
Keep the drain line open to the atmosphere and
NOT under water or other substances.
• Ensure that the condensate drain, PRV, and
T&P Relief Valve are piped separately to their
own dedicated drain lines.
• If the condensate drain gets blocked, a
diagnostic code will display on the controller.
If this occurs, the condensate drain must be
cleaned.
• The condensate trap will automatically prime
(self-prime) during operation of the unit as
condensate forms. Condensate draining from
the unit indicates that the trap is full and that
there is no blockage in the condensate drain.
It is not necessary to add water to the
condensate trap.
• A condensate neutralizer kit is available from
Rinnai. The kit allows condensate to flow
through neutralizing media that raises the pH
of the condensate to a level that will help
prevent corrosion of the drain and public
sewer system.
CORRECT
Drain line open to
atmosphere
Water
Drain line submerged
in water
NOT CORRECT
Water
Condensate Drain Line
(1/2 in. Clear Vinyl Tubing)
• All condensate must drain and be disposed
of according to local codes.