Heavy Duty Gas Indoor A621275

Commercial Storage Gas

Model Number: Heavy Duty Gas Indoor A621275

Rheem Heavy Duty Gas water heaters have been designed to supply large quantities of hot water. The cylinder is protected by multiple anodes and a double layer of vitreous enamel.

  • Designed for greater protection
  • Adjustable thermostats
  • Equa-Flow® system allows for flexibility in installation

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DIMENSIONS AND TECHNICAL DATA TABLE - INDOOR MODEL
Storage Capacity   litres 275
Dimensions      
  A mm 1895
  B mm 640
  C mm 780
  D mm 760
  E mm 700
  F mm 340
  G mm 1695
  H degrees 36
  K mm 722
  L mm 320
  M mm 200
  P mm -
Weight - Empty   kg 187
Inlet/Outlet Connections (BSPF)     RP1¼/32
Gas Connection (BSPF)     RP¾/20
T&PR Valve Connection (BSPF)     RP¾/20
T&PR Valve Setting   kPa 1000
Expansion Control Valve (ECV)10 Setting   kPa 850
without ECV10 fitted   kPa 800
with ECV10 fitted   kPa 680
Max. Thermostat Setting   °C 82
Factory Thermostat Setting   °C 70
Min. Thermostat Setting   °C 60
Manifold - Min. Centre to Centre   mm 890
Electrical Connection     2m 10A Plug and Lead
Electrical Rating 240V 50Hz     150 Watts
      0.65 Amps

PERFORMANCE DATA
No. of Units
in Parallel
Initial Storage
Capacity
Thermal Input Litres hot water at 50°C rise over peak period (based on natural gas)
  (Litres) (MJ/h) 1 hour 2 hours 3 hours 4 hours 6 hours 8 hours
1 275 200 970 1710 2460 3200 4690 6180
2 550 400 1930 3420 4910 6400 9380 12370
3 825 600 2900 5130 7370 9600 14080 18550
4 1100 800 3860 6840 9820 12810 18770 24730
5 1375 1000 4830 8550 12280 16010 23460 30910
6 1650 1200 5790 10260 14740 19210 28150 37100
No. of Units in Parallel Initial Storage Capacity Thermal Input Litres hot water at 65°C rise over peak period (based on natural gas)
  (Litres) (MJ/h) 1 hour 2 hours 3 hours 4 hours 6 hours 8 hours
1 275 200 790 1370 1940 2510 3660 4810
2 550 400 1590 2730 3880 5030 7320 9610
3 825 600 2380 4100 5820 7540 10980 14420
4 1100 800 3170 5470 7760 10050 14640 19230
5 1375 1000 3970 6830 9700 12570 18300 24030
6 1650 1200 4760 8200 11640 15080 21960 28840

Operations at temperatures above 80°C

Rheem commercial gas models 621 265, 631 265, 621 275, 631 275 are designed to operate at temperatures up to 82°C for sanitising and other applications.

Where the water supplied by the water heater is required consistently at any temperature above 80°C, we strongly recommend you use a pumped recirculation system. (Please refer to the Equa-Flow® section.)

Gas pipe supply

The gas supply piping should be sized in accordance with AS/NZS5601.1

The gas supply pipe must be sized so that the minimum gas pressure is available at the inlet to each water heater when all appliances are operating at maximum gas consumption.

The minimum gas pressures are 1.13 kPa for natural and SNG, 2.75 kPa for propane and butane and 0.75 kPa for town gas and TLP.

TECHNICAL GAS PERFORMANCE DETAILS
Gas Type   Nat/SNG Propane Butane
Thermal Input MJ/h 200 190 160
Output kW 43.3 41.2 34.7
Min. Gas Supply Pressure kPa 1.13 2.75 2.75
Test Point Pressure kPa 0.90 2.65 2.65
Max. Gas Supply Pressure kPa 3.5 3.5 3.5
Litres Recovery Per Hour at Rise of 20°C 1870 1780 1500
  30°C 1250 1190 1000
  40°C 940 890 750
  50°C 750 710 600
  60°C 630 600 500
  65°C 580 550 460
  70°C 540 510 430
  75°C 500 480 400

Approximate daily energy consumption

These daily gas consumption figures are approximate. They’re based on:

  • A daily usage of hot water per water heater in litres, at 50°C rise
  • Using natural gas, but they can be used with reasonable accuracy for other gas types
  • Mains pressure supply systems only

The figures do not allow for pipe heat losses. An additional allowance must be made for large manifold systems and installations designed with a circulated flow and return system.

Use the table to calculate

  • The approximate energy cost for a particular installation
  • The average daily hot water consumption when the energy consumption is known
APPROXIMATE DAILY ENERGY CONSUMPTION
Daily Hot Water Usage @ 50°C Temp Rise Energy Content of Hot Water Approximate Energy Used Per Day Natural Gas
(Litres) (MJ) (MJ)
0 0 26.1
50 10.5 39.6
100 20.9 53.1
150 31.4 66.5
200 41.9 80.0
250 52.3 93.5
300 62.8 106.9
350 73.3 120.4
400 83.7 133.9
450 94.2 147.3
500 104.7 160.8
600 125.6 187.8
700 146.5 214..7
800 167.4 241.6
900 188.4 268.6
1000 209.3 295.5
1250 261.6 362.8
1500 314 430.2
1750 366.3 497.5
2000 418.6 564.9
2500 523.3 699.6
3000 627.9 834.2
3500 732.6 968.9
4000 837.2 1103.6
5000 1046.5 1373.0

To convert to kg of Propane, divide MJ by 49.5. To convert to litres of Propane, divide MJ by 25.3.

Ventilation for indoor gas water heaters

It’s a requirement of AS/NZS5601.1 that indoor gas water heaters (non room sealed) are installed in a location with adequate ventilation.

Two permanent openings are required into the room housing the water heaters.

The distance from the top of the upper opening to the ceiling and from the bottom of the lower opening to the floor, cannot each exceed 5% of the room height.

The two openings can be combined, as long as the top and bottom of the opening are within the 5% distance requirement.

The minimum vertical dimension of any free ventilation opening is 6mm.

The minimum free ventilation area of each opening required for each Rheem commercial gas water heater installed is shown in the table.

Please refer to AS/NZS5601.1 for full details of the requirements.

Notes

  1. Although a room sealed water heater installation draws the air required for combustion from outside, ventilation may be necessary to prevent a rise in the ambient temperature in the room.
  2. In plant rooms, wherever possible more than one wall should be used to provide ventilation. This allows a flow of air across the room and helps prevent excessive temperatures in the room.
  3. In rooms other than plant rooms, ventilation is required if the total thermal input of the water heaters exceeds 3 MJ/h per cubic metre of room volume.
  4. AS/NZS5601.1 should be consulted for further requirements when ventilating through adjacent rooms to the water heater installation.
VENTILATION REQUIREMENTS
  Natural Ventilation
(Area of Each Opening Per Water Heater)
Mechanical Ventilation
(Per Water Heater)
  Location of Water Heater      
  Plant Room Non Plant Room Low Level High Level
Thermal
Input
Direct to
Outside
via Adjacent
Room
Direct to
Outside
via Adjacent
Room
Mechanical
Air Supply
Mechanical
Exhaust
Natural
Exhaust
MJ/h (cm2) (cm2) (cm2) (cm2) (L/s) (L/s) (cm2)
200 300 600 600 1200 100 29 300

Natural air supply with a mechanical exhaust is not permitted.

Power fluing

You can either install an individual Rheem gas model or a bank of multiple 621 265, 621 275 models with a power flue.

It’s essential to prove the flue system operates correctly before the main burner is allowed to operate.

How do you achieve this? A self proving relay interconnected with either a vane switch or pressure differential switch will prove both air flow and functionality of the control circuit before ignition of the main burner.

Please refer to AS/NZS5601.1 for full details of what’s required.

For multiple installations, the operating principle is the same as for a single water heater.

Any water heater can switch on the fan, and the burners can only come on when the sail switch is closed.

Intermittent PowerFlue Fan Control – Multiple Water Heater Rheem 621 Series & Raypak Type B Series.

Power Flue and Remote control

Rheem commercial models 621 265, 631 265, 621 275, 631 275 may be controlled by a remote device such as a time clock, remote isolating switch, pressure switch or sail switch. Additionally, Rheem can assist with Power Flue design solutions for Rheem and Raypak® commercial gas water heaters. For further details please contact your local Rheem technical advisory service.

Fluing: indoor gas water heaters

Rheem indoor gas water heaters are designed for connection to a flue system in accordance with the requirements of AS/NZS5601.1.

Manifolded water heaters can either be flued individually or connected to a common flue. The design of the flue must comply with Appendix H of the Standard.

AS/NZS5601.1 states the vertical rise directly out of the water heater must be the maximum possible height before any change in direction.

Also, the total length of the lateral (horizontal) section must be as short as possible, not exceeding 50% of the total flue height of the system.

The table and diagram below are extracted from the Flue Tables in AS/NZS5601.1 and are meant as a quick guide only. Any variations should be referenced from AS/NZS5601.1.

Appropriate authorities should be consulted before any work is commenced on flues other than single appliance flues.

Multiple Manifold Flue System

FLUE SIZING FOR GAS WATER HEATERS
    1 2 4 6 8
  Total Flue Height Max. Lateral Flue Dia Max. Manifold Flue Dia Max. Manifold Flue Dia Max. Manifold Flue Dia Max. Manifold Flue Dia
  (H)     Length (A)   Length (A)   Length (A)   Length (A)  
Model (m) (m) (mm) (m) (mm) (m) (mm) (m) (mm) (m) (mm)
621 275 2 1 175 1 250 - - - - - -
200 MJ/h 3 1.5 175 1.5 250 - - - - - -
  6 3 150 3 200 3 300 - - - -
  12 6 150 6 200 6 250 6 300 - -
  24 7.6 150 12 175 12 250 12 300 12 300

Notes:

  • The table is based on a natural draft system with an insulated type flue or a flue installed indoors
  • The table is extracted from the Flue Tables in AS/NZS5601.1 and is meant as a quick guide only. Any variations should be referenced from AS/NZS5601.1

Technical Documents

Performance Calculator View Online
Sample Specification View Online
Manifolding View Online
Flue Damper View Online
Product Drawings - 1 Unit Download
Product Drawings - 2 Units Download
Product Drawings - 3 Units Download
Product Drawings - 4 Units Download
Product Drawings - 5 Units Download
Product Drawings - 6 Units Download
Product Drawings - 7 Units Download
Product Drawings - 8 Units Download
Installation Instructions Download
Brochure Download