Installation Manual
H-Series Demand Duo™ 2 Installation and Operation Manual 17
Gather the recommended tools and materials
before starting installation.
Contaminant Maximum Level
Total Hardness Up to 200 mg/L
Aluminum * Up to 0.2 mg/L
Chlorides * Up to 250 mg/L
Copper * Up to 1.0 mg/L
Dissolved Carbon Dioxide (CO2) Up to 15.0 mg/L
Iron * Up to 0.3 mg/L
Manganese * Up to 0.05 mg/L
pH * 6.5 to 8.5
TDS (Total Dissolved Solids) * Up to 500 mg/L
Zinc * Up to 5 mg/L
When selecting an installation location, you must
ensure that clearances will be met and that the
vent length will be within required limits. Consider
the installation environment, water quality, and
need for freeze protection. Requirements for the
gas line, water lines, electrical connection, and
condensate disposal can be found in their
respective sections in this manual.
For vent termination clearances, refer to the
Tankless Water Heater Installation and Operation
Manual supplied with the Demand Duo™ 2
system.
* Source: Part 143 National Secondary Drinking
Water Regulations
This section provides information on the
importance of water quality to the Rinnai
Tankless Water Heater. The information is
intended to serve as general guidelines only and
Consideration of care for your water heater
should include evaluation of water quality. The
water must be potable, free of corrosive
chemicals, sand, dirt, or other contaminants. It is
up to the installer to ensure the water does not
contain corrosive chemicals or elements that can
affect or damage the Rinnai Tankless Water
Heater. Water that contains chemicals exceeding
the levels below can damage the Rinnai
Tankless Water Heater. Replacement of
components due to water quality damage is not
covered by the warranty.
• Pipe wrenches (x2)
• Phillips Head screwdriver
• Adjustable pliers
• Wire cutters
• Hoisting straps (able to support approxi-
mately 220 lb/100 kg)
• Gloves
• Safety glasses
• Level
• Soap or gas leak detector solution
• Approved venting
• Teflon tape (recommended) or pipe com-
pound
• Pipe insulation
• Hammer drill with concrete bits
• Saw
• Threading machine with heads and oiler
• Core drill with diamond head
• Torch set
• Copper tubing cutter
• Steel pipe cutter
• Heat tape
• 5/8 in. ID PVC flexible tubing
• Electrical wire
• Concrete wall anchors
• Optional pipe cover
• PVC glue/cement and primer
• 2 conductor 22 AWG wire for controller
• Single gang electrical box
• Wire nuts
• Unions and drain valves
• Drain pan
• Earthquake strap