Rheem RTGH-S84i Tankless Water Heaters Owner’s Manual

June 1, 2024
Rheem

Rheem RTGH-S84i Tankless Water Heaters

Easy Installation

  • PVC Vent runs up to 70′ (2″), 150′ (3″)
  • Easy set up with full text digital display and no dip-switches
  • Field gas convertible from natural gas to LP – conversion kit included

Ready for Retrofits

  • Allows flex venting through existing B-vent up to 50′
  • 1/2″ Gas line compatibility up to 24 ft (subject to local code)
  • Approved for installations in Manufactured Home (Mobile Home) environments

Key Features

  • Stainless steel Primary and Secondary heat exchangers provide increased efficiency and durability
  • Rheem® Exclusive! Hot-start programming™ ensures the unit is in a ready state between back-to-back usage, avoiding any cold water bursts
  • Built-in Recirculation pump for no wait continuous hot water at the tap (SR models)
  • Built-in EcoNet® Wi-Fi technology for direct control from your device (optional for S models)

Specifications

Rheem Model Number| RTGH-S84i RTGH-SR84i| RTGH-S10i RTGH-SR10i| RTGH-S11i RTGH-SR11i
---|---|---|---
Gas Input Rate| MAX| 157,000 BTU/h| 180,000 BTU/h| 199,900 BTU/h
MIN| 11,000 BTU/h| 11,000 BTU/h| 11,000 BTU/h
Uniform Energy Factor (UEF)| 0.96
Hot Water Flow Rate Capacity – Gallons Per Minute (GPM)| MAX (35°F)| 8.4| 10.1| 11.2
45°F Rise| 6.9| 7.9| 8.8
67°F Rise| 4.6| 5.3| 5.9
Number of Bathrooms 1|  |  |
Temp. Range| 85°F – 140°F
Temp. Setting from Factory| 120°F
Installation Type| Indoor (Outdoor Conversion Kit sold separately: RTGH-SX)
Fuel Type| Compatible with Natural Gas and LP (ships NG with LP conversion kit included)
Heat Exchanger Material| Primary: Stainless Steel – Secondary: Stainless Steel
Minimum Activation Flow| 0.4 GPM
Minimum Continuous Flow| 0.26 GPM
Maximum Altitude| 10,200 ft.
Ultra Low NOx| Meets 14 ng/J NOx requirements – SCAQMD Rule 1146.2 compliant
Warranty| 15 Year Heat Exchanger | 5-Year Parts | 1-Year Labor
Model Number| RTGH- S| RTGH- SR
---|---|---
Height| 28-9/16″
Width| 17-5/16″
Depth| 13-11/16″
Weight| 77.6lbs| 86lbs
Venting Diam. Allowed| 2″ / 3″
Max. Single Vent Run (straight pipe)| 70 ft (2″)/ 150 ft (3″)
Venting Materials| Sched. 40 PVC, CPVC, Polypropylene
Common Venting (max. units)| 2 units3
Flex Venting| Allowed: 2″ up to 50′
Manifold Controls (max. units)| Up to 20 units without external control required4
Controls| Built-in digital display with full-text menus
Power Supply| 120V 60Hz
__

Max. Power Consumption

| 85W (Normal use), 0.7Amps 132W (Anti freeze only), 1.1Amps

3.5W (Standby), 0.03Amps5

| 100W (Normal use), 0.83Amps 200W (Anti freeze), 1.67Amps

3.5W (Standby), 0.03Amps5

Gas Connection| 3/4″ NPT
Hot Water Connection| 3/4″ NPT
Cold Water Connection| 3/4″ NPT
Condensate Connection| 1/2″ NPT
Vent Connections Diameter| 2″ Band Connections (Adapter required to vent with 3″ PVC from unit)

CLEARANCES

CLEARANCES

Top / Bottom| 12″
Front| 1/2″6
Sides| 1/2″
Back / From Vent Pipe| 0″

RECIRCULATION LENGTH (SRI MODELS)

Pipe Diameter Max. Recirculation Loop
3/4″ 400 ft.
1/2″ 100 ft.

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  1. Based on simultaneous showers using 2 GPM flow rate pre-mixed with cold water line. Flow rates vary depending on temperature of incoming cold water and water heater set temperature. Refer to capacity table by zone for accurate sizing.
  2. For indoor application, this is the temperature of outdoor intake air.
  3. External check valve required for installation.
  4. Manifolds with standard RJ25 communication cables.
  5. If anti freeze is on and combustion is on, total W will be 217W (85+132).
  6. Recommended 24″ clearance for service.

US Ground Water Temperature Zone Map

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Average Flow Rates (GPM) by Application

Low Flow Faucet 0.5
Bathroom Faucet 1
Kitchen Faucet 1.5
Shower 2
Dishwasher 2
Washing Machine 3

Flow Rate Capacity Table by Zone (Gallons Per Minute – GPM)
Use the U.S. Ground Water Temperature Map to locate your zone. Then use the Flow Rate Capacity Table to determine model flow rate by zone. Flow rates calculated for tankless set temperature of 120°F with a mixed shower temperature of 105°F.

MODEL #| Zone 1 37°F| Zone 2 42°F| Zone 3 47°F| Zone 4 52°F| Zone 5 57°F| Zone 6 62°F| Zone 7 67°F| Zone 8 72°F| Zone 9 77°F
---|---|---|---|---|---|---|---|---|---
RTGH-S(R)11i| 4.7| 5.1| 5.4| 5.9| 6.3| 6.8| 7.4| 8.2| 9.2
RTGH-S(R)10i| 4.3| 4.6| 4.9| 5.3| 5.6| 6.1| 6.7| 7.4| 8.3
RTGH-S(R)84i| 3.7| 4.0| 4.2| 4.6| 4.9| 5.3| 5.8| 6.4| 7.2

Venting

SINGLE UNIT: MAX. EQUIVALENT VENT LENGTHS – STRAIGHT PIPE

Number of 90 Elbows| Max Length 2″ straight pipe| Max. length 3″ straight pipe
0| 70 ft. (21.3 m)| 150 ft. (45.7 m)
1| 64 ft. (19.5 m)| 145 ft. (44.2 m)
2| 58 ft. (17.7 m)| 140 ft. (42.7 m)
3| 52 ft. (15.8 m)| 135 ft. (41.1 m)
4| 46 ft. (14.0 m)| 130 ft. (39.6 m)
5| 40 ft. (12.2 m)| 125 ft. (38.1 m)
6| 34 ft. (10.4 m)| 120 ft. (36.6 m)

EQUIVALENT FT. OF ELBOWS

  2″ Pipe 3″ Pipe
90° Elbow 6 ft (1.83 m) 5 ft (1.52 m)
45° Elbow 3 ft. (0.9 m) 2.5 ft. (0.75 m)

Venting Materials Allowed: Schedule 40 PVC, CPVC, Polypropylene

MIN. VENT LENGTH STRAIGHT PIPE

Number of 90° Elbows Min. Length 2″ 3″ pipe
1 1.0 ft (0.3 m)

COMMON VENTING

# of Water Heaters 3″ Common Vent
2 60 ft.

SINGLE UNIT: MAX. FLEX VENTING

Max Length 2″ flex vent

50 ft.

Dimensions

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TOP VIEW

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BOTTOM VIEW

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Hanging bracket, bird screens, LP gas conversion kit are included with water heater.

Parts & Accessories

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In keeping with its policy of continuous progress and product improvement, Rheem reserves the right to make changes without notice.

Rheem Water Heating • 1115 Northmeadow Parkway, Suite 100
Roswell, Georgia 30076 • www.rheem.com

References

Read User Manual Online (PDF format)

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