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WARNING If the information in these instructions is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other —...
Contents Welcome ............................3 Safety ..............................4 About the Common Venting System ....................5 Venting Guidelines ..........................5 Schedule 40 PVC/CPVC Common Vent Guidelines ................7 High Altitude Installations........................8 Common Vent Maximum Equivalent Lengths ..................9 3 in. Common Venting ........................10 3 in.
Water Heater Installation and Operation Manual or view an online version at rinnai.us. Illustrations of tankless water heaters in this document represent one of the applicable Rinnai tankless water heaters. Your water heater may look different than the images in this document.
DO NOT apply PVC/CPVC glues, solvents, or cleaners to the tankless water heater’s intake or exhaust gasket connections. Failure to correctly assemble the components according to these instructions and the Rinnai water heater installation and operation manual may result in property damage, personal injury, or death.
Vent Lengths Common venting allows multiple Rinnai Tankless Water Heaters to share the same vent system. Rinnai Tankless Water Heaters can only be common vented with Schedule 40 PVC/CPVC or with a Rinnai certified common vent system. Example: Rinnai Common Venting...
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Do Not • Do not exceed the maximum number of units indicated in the Rinnai Tankless Water Heater Installation and Operation Manual. • Do not use cellular core PVC/CPVC, Radel, ABS or galvanized material for the exhaust vent.
Schedule 40 PVC/CPVC Common Vent Guidelines WARNING PVC solvents (primer and glue) can be extremely flammable. Vapors may cause a flash fire or explosion resulting in property damage, personal injury or death. • Keep solvents away from heat, sparks, flames and all other sources of ignition. •...
• High altitude installations are certified up to 10,200 ft (3,109 m). • Reference the respective Rinnai Tankless Water Heater Installation and Operation Manual to set the water heater up for the altitude at which they will be operating. •...
• Use 10 ft (3 m) as equivalent vent length for 90° elbows. • For use with SENSEI internal (indoor) tankless water heaters. Common Vent Maximum Equivalent Vent Length / Rinnai Common Vent System or Schedule 40 PVC/CPVC HEADER DIAMETER...
3 in. Common Venting Direct Vent Inline EXHAUST INTAKE Room Air • Refer to the “Combustion Air Requirements” section of this manual for room air requirements. Inline EXHAUST INTAKE INTAKE PVC/CPVC Common Venting Installation Instructions...
4 in. Common Venting Direct Vent • Maximum 4 Units Back-to-Back Inline Room Air • Maximum 4 Units • Refer to the “Combustion Air Requirements” section of this manual for room air requirements. Inline Back-to-Back INTAKE INTAKE PVC/CPVC Common Venting Installation Instructions...
6 in. Common Venting Direct Vent • Maximum 12 Units Back-to-Back Inline Room Air • Maximum 12 Units • Refer to the “Combustion Air Requirements” section of this manual for room air requirements. Inline Back-to-Back PVC/CPVC Common Venting Installation Instructions...
Sample Horizontal Termination Assembly Support Brackets Required 4 ft (1.2m) Maximum Between Brackets Exhaust Termination: Tee or Elbow 6 ft (1.8m) Maximum Between Brackets • Header Tees Should be Schedule 40 Drain Tees. • Sharp Turn Tee’s or Elbows are not recommended due to the increased resistance.
Sample Vertical Termination Assembly-Room Air Support Brackets Required Exhaust Termination: Elbow 6 ft (1.2 m Maximum Between Brackets • Header Tees Should be Schedule 40 Drain Tees. • Sharp Turn Tee’s or Elbows are not recommended due to the increased resistance. 4 ft (1.2 m Maximum Between Brackets...
The design of such an enclosure shall be deemed acceptable by the installer or the local inspector. Water Heater Clearances Refer to the Rinnai Tankless Water Heater Installation and Operation Manual for minimum clearance requirements around the water heater.
12 in. minimum from edge of exhaust termination to edge of combustion air termination. There should be a minimum of 36 in. (91 cm) between exhaust terminations in multiple common vent installations. Refer to the Rinnai Tankless Water Heater Installation and Operation Manual for maximum vent lengths based on the vent diameter installed.
Combustion Air Requirements Common Vent Applications Utilizing Room Air Condensate Trap 6 in (152 mm) Minimum This rack system requires adequate combustion air for ventilation and dilution of flue gases. Failure to provide adequate combustion air can result in unit failure, fire, explosion, serious bodily injury or death. Use the following methods to ensure adequate combustion air is available for correct and safe operation of this rack system.
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Louvers and Grills When sizing the permanent opening, consideration must be taken for the design of the louvers or grills to maintain the free area required for all gas utilizing equipment in Exhaust the space. If the free area of the louver or grill design is not available, assume wood louvers will have 25% free area and metal louvers or grills will have 75% free area.
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Vent termination per ANSI Z223.1/NFPA 54. For When communicating indirectly with the outdoors clearances not specified in ANSI Z223.1/NFPA 54, through vertical ducts, each opening shall have a clearances are in accordance with local installation codes minimum free area of 1 in /4,000 Btu/hr (550 mm /kW) and the requirements of the gas supplier.
Exhaust Vent Termination Clearances The information below applies to Concentric and Twin Pipe: TERMINATION SNOW Regulator vent outlet. In the event no regulator is present, H and I can be disregarded. Canadian Installations U.S. Installations (CSA B149.1) (ANSI Z223.1/NFPA 54) Description Direct Vent (Indoor Unit) Direct Vent (Indoor Unit)
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Exhaust Vent Termination Clearances Other than direct vent, when using room air for combustion, you must install terminations to expel exhaust. Room Air and External Termination Clearances TERMINATION SNOW Regulator vent outlet. In the event no regulator is present, H and I can be disregarded. Canadian Installations U.S.
Additional Clearances Check on whether local codes supersede the clearances below. • Avoid termination locations near a dryer vent. • Avoid termination locations near commercial cooking exhaust. • You must install a vent termination at least 12 in. (305 mm) above grade or snow line. The vent for this appliance shall not terminate •...
□ Leave this manual taped to one of the water warranty. heaters or give the entire manual directly to the consumer. Copyright 2024 Rinnai America Corporation. Rinnai® is a registered trademark of Rinnai Corporation used 100000625(04) under license by Rinnai America Corporation. Rinnai America Corporation continually updates materials, 5/2024...
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