Electric Low Capacity

Light Duty Commercial

Electric cement lined water heater Model E
  • Light Duty
  • 6 - 119 Gallon Capacity
  • Up to 12KW - 1 Phase or 3 Phase

Ceiling Hung Horizontal

Electric horizontal ceiling hung water heater Model HE/HSE
  • Horizontal, Ceiling Hung
  • 19 or 30 Gallon Capacity
  • Up to 20 KW - 1 or 3 Phase

Heat Pump

Hybrid electric heat pump water heater Model PBX
  • Heat Pump Water Heater
  • 40 - 119 Gallon Capacity
  • 1 or 3 Phase

Point-Of-Use Water Heater

Mini compact point of use water heater
  • Point-of-Use
  • 2.5 Gallon Capacity
  • Digital Display

Point-Of-Use Storage

Point-of-use electric water heater Model CE110
  • Point-of-Use
  • 1 Gallon Capacity
  • 1000 or 450 Watts - 1 Phase

Point-Of-Use Tankless

Electric tankless point-of-use water heater Model R Tankless
  • Whole House / Point-of-Use
  • Availabe 3 thru 27 KW - 1 Phase

Circulation (Instantaneous)

Electric circulation heater Hubbell Model CR
  • Circulation (Instantaneous)
  • Heavy Duty Construction
  • 25-1600 KW - 1 or 3 Phase

Industrial Process Heater

Model V16
  • Process Systems & Industrial
  • ASME Stamped
  • Up to 88 KW - 1 or 3 Phase

Heavy Duty Commercial

Commercial heavy duty electric storage water heater Model SE
  • Heavy Duty
  • 6-119 Gallon Capacity
  • Up to 58 KW - 3 Phase

Tankless Commercial

Electric tankless water heater Model HX/TX
  • Tankless Commercial
  • Highly efficient tankless
  • Up to 162 KW - 1 or 3 Phase

Large ASME

Large capacity electric storage tank water heater Model SH
  • Large Capacity
  • 80-5000 Gallon Capacity
  • All KW ratings - 1 or 3 Phase

Commercial Condensing Gas Water Heater

Gas tankless water heater Model NX
  • High Efficiency Condensing Burner
  • 316L SS ASME Heat Exchanger
  • BTU input from 200,000 to 800,000 MBH

Commercial/ Industrial
Condensing Gas Water Heater

Gas tankless water heater Model NXT
  • High Efficiency Condensing Burner
  • 316L stainless steel and ASME stamped heat exchanger
  • BTU input from 200 to 400 MBH

DI / RO Gas

DI/RO gas fired tankless water heater Model DGX
  • DI/RO Water Heater
  • High Efficiency Condensing Burner
  • 199,950 and 250,000 BTU

Condensing Gas
Storage Water Heater

Condensing gas storage tank water heater Prime
  • High Efficiency Condensing Burner
  • Removable 316L SS Heat Exchanger
  • 55,000 BTUs

Large ASME
Steam Heater

Steam fired water heater large capacity Model ST
  • Storage Type
  • 80-5000 Gallon Capacity
  • ASME Stamped

Packaged Semi-Instantaneous

Semi-Instantaneous Steam Fired Water Heater Model STX
  • Semi-Instantaneous
  • Space saving design
  • Provides 10,500 GPH


Storage tank steam fired water heater Model PS
  • Light Duty
  • 65-119 Gallon Capacity
  • For low demand/recovery

High Capacity Instantaneous

Instantaneous steam fired water heater Model F
  • Instantaneous
  • 7 Sq. Ft. of floorspace
  • Up to 120 GPM

Semi-Instantaneous Indirect

Indirect fired semi-instantaneous water heater Hubbell Model BWX
  • Semi-Instantaneous
  • Vertical or Horizontal
  • ASME Stamped

Large ASME

Indirect fired storage tank water heater Hubbell Model BW
  • Storage Type
  • Vertical or Horizontal
  • 80-5000 Gallon Capacity

Small Capacity Indirect

Indirect fired storage tank water heater model T Transflow
  • Indirect Fired
  • 35-119 Gallon Capacity
  • Utilizes boiler water


Solar water heater Model SLN
  • Solar Heater
  • Vertical Storage Type
  • 65-119 Gallon Capacity

Indirect Plate Heat Exchanger

Plate Heat Exchanger Indirect Fired Water Heater Model BWP
  • Fully Packaged System
  • Full Range of Styles/Sizes
  • Storage Type

Indirect Plate Heat Exchanger

Plate Heat Exchanger Indirect Fired Water Heater Model BWXP
  • Compact Design
  • Instantaneous
  • Replaceable brazed plate or plate and frame


ASME and None ASME storage vessels Hubbell Model StorageTank
  • ASME & Non ASME designs
  • Hydrastone Cement
  • Vertical or Horizontal


ASME and None ASME storage vessels Hubbell Model BufferTank
  • Carbon Steel Construction
  • Long Warranty
  • ASME Section VIII, Division 1


Electric hazardous location water heater Model ER
  • Hazardous Location
  • 10-5000 Gallon Capacity
  • Up to 1600 KW - 1 or 3 Phase

Tepid Water for Emergency Fixtures

Electric safety shower water heater Model EMV
  • Emergency Tepid Water
  • Fully packaged system
  • Integrated mixing valve

Industrial Process Heater

Model V16
  • Process Systems & Industrial
  • ASME Stamped
  • Up to 88 KW - 1 or 3 Phase

RO / DI Heater Compact

DI/RO electric hot water heater Model HD
  • RO/DI Water Heater
  • Point-of-Use Heater
  • Up to 88 KW - 1 or 3 Phase

RO / DI Heater Storage

DI/RO electric hot water heater Model D
  • RO/DI Water Heater
  • 1-119 Gallon Capacity
  • Up to 88 KW - 1 or 3 Phase

Emergency Shower Tankless

Electric tankless safety shower water heater Model ETX
  • Tankless Emergency Tepid Water
  • NEMA 4 Standard
  • Up to 88 KW - 1 or 3 Phase

Fully Integrated Package

Model Packaged Skid Electric Fluid Heating System
  • Customized to your specifications
  • Full featured system ready for your application

Industrial Process Heater

Electric process industrial water heater Model V
  • Customized to your specification
  • Full featured system ready for your application

Light Duty

Electric water heater for shipboard marine use single phase power Model ME
  • Light Duty
  • 6-119 Gallon Capacity
  • Up to 6 KW - 1 Phase

Heavy Duty

Electric water heater for shipboard marine use three phase power Model MSE
  • Vertical
  • 6-119 Gallon Capacity
  • 1 or 3 Phase - Up to 58 KW

Large ASME

Electric water heater for shipboard marine use large capacity Model MSH
  • Large Capacity
  • 80-5000 Gallon Capacity
  • All KW ratings - 1 or 3 Phase


Naval shipboard marine electric water heater Hubbell Model 177
  • MIL Spec Navy Heaters
  • Comforms to MIL-H-965
  • Shock and EMI protection


Electric tankless water heater for shipboard marine use model MHX/MTX
  • Tankless Marine Heater
  • Provides 180°F water
  • 11 to 54 KW - 1 or 3 Phase

Fully Integrated Package

Shipboard Electric Water Heating System Model Integrated Skid
  • Customized to your specifications
  • Full featured system ready for your application

Electric Booster

Electric booster water heater Model J
  • Booster Heater
  • Provides 180°F water
  • Up to 88 KW - 1 or 3 Phase

Foodservice Tankless
Electric Booster

Electric tankless booster heater Model JTX
  • Tankless Booster Heater
  • Provides 180°F water
  • 11 to 54 KW - 1 or 3 Phase

Foodservice Gas
Fired Booster Heater

Gas fired booster heater Model PT
  • Gas Booster Heater
  • High Efficiency Condensing Burner
  • 55,000 to 199,000 BTU

Foodservice Point-of-Use
Water Heaters

Mini compact 2.5 Gallon Booster Heater
  • Hot water for remote locations
  • Perfect for glasswashers
  • 120V models available

Foodservice Sanitizing
Sink Heater

Model JSK
  • Provides rinse water for manual warewashing
  • Perfect for 3 compartment sinks
  • Available in 3,4,6 or 9 KW

Food Rethermalizer Baine-Marie Heater

Model JFR
  • Mounts under sink or holding vessel
  • Keeps food at SERV safe temperature
  • Available up to 9 KW

Foodservice Point-of-Use
Water Heater

Compact point-of-use electric water heater Model J1SSA
  • Point-of-Use
  • 1 Gallon Capacity
  • 1000 Watts - 1 Phase

Immersion Heating

Electric immersion tubular style heaters
  • Immersion Electric Heaters
  • Flanged or Screw Plugs Types
  • All KW ratings - 1 or 3 Phase

Heat Transfer

Heat exchanger and heating coil water heaters
  • Immersion Heat Transfer Coils
  • U tube type
  • Range of Materials

Stainless Steel T & P
Relief Valve

Stainless Steel T & P Relief Valve
  • 316 L Stainless Steel construction
  • Corrosion Resistant
  • ASME Section IV, HV Stamped

Gas Heat Exchanger

gas hx
  • 316 L SS Heat Exchanger/Burner
  • 55,000 BTU/HR input
  • Digital temperature controller
Electric High Capacity
Gas Fired
Steam Fired
Special Purpose
Foodservice Equipment
Elements & Exchangers
Product Center
Electric tankless point-of-use water heater Model R
Still have questions? Complete this form
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Tankless Electric Water Heater

Point-of-Use Water Heater

Available 3-27 KW Single Phase Voltages

The Hubbell Tankless electric water heater is a highly reliable and easily maintained heater designed for point-of-use or whole house operation. The Hubbell Tankless electric water heater is compact, extremely efficient, takes up minimal space and reduces operating costs. Hubbell's vast experience, meticulous engineering and advanced technology ensure that you can rely on the Hubbell Tankless heater for your water heating needs in even the most demanding applications. The Hubbell Tankless is the right choice for your water heating needs and provides you with an energy efficient, trouble-free and long lasting heater.

Lead Free Product cULUS Listed ANSI NSF 5
  • Heavy Duty Construction

    • Constructed with high grade materials to ensure long operating life
    • Simple to install and operate
    • Compact space saving design
  • Reliability

    • Engineered to ensure reliable operation
    • Wide selection of sizes
  • High Efficiency

    • On demand heating eliminates costly and cumbersome storage tanks
    • Instantaneous design reduces stand-by heat loss and significantly lowers operating costs compared to traditional storage tanks

How It Works

How It Works

The Hubbell tankless electric water heater contains high powered heating elements that heat water only when there is demand for hot water. When hot water is needed, a built in flow sensor measures the exact flow rate and that data combined with temperature readings at the heater's inlet and outlet are processed by the electronic temperature controller. This data is continuously transmitted to the temperature controller, which constantly calculates the precise amount of power (kW) needed to achieve the desired temperature. A zero cross over firing signal is sent to the fast acting triacs in order to module the heating elements to the precise level needed to meet demand. The Hubbell tankless heater uses only as much power as is needed, while delivering accurate and consistent hot water temperature.

Tankless Water Heater Specifications

Heating Chamber: Copper and Bronze
Capacities: 3 thru 27 kW
Orientation: Wall Mounted
Voltage: 240 / 220 / 208 Volt
Phase: 1 Φ
Power Factor: 0.999
Thermal Efficiency: 98% +
Inlet / Outlet Size: 3/4" Push Fit
Min / Max Flow: 0.2 GPM Min, 8.0 GPM Max
Thermostat Range: 32-140°F / 0-60°C
Hi-Limit: 150°F (65°C)
Design WP: 150 psi
Design TP: 300 psi
Element: Incology 800
Standby Power: < 3 Watts
Chamber Warranty:
Residential: 5 Years
Commercial: 5 Years
Electric Warranty:
Residential: 1 Year
Commercial: 1 Year
Enclosure: Stainless Steel Brushed Finish
Approvals: cULus, UL EPH ANSI / NSF5
Maximum Inlet Temp.:150°F

General Specifications

Temperature Controller

A sophisticated electronic temperature controller with LED digital display provides the user interface. The temperature controller processes all flow and temperature data and calculates the precise amount of power needed to meet demand.

Operator Control Capabilities
Checkmark Power Limiting: Allows the operator to reduce the power consumption by any percentage to provide installation and operational flexibility and savings.
Checkmark Diagnostics: Display inlet and outlet temperatures, flow rate and error codes to assist in troubleshooting.
Checkmark Cost Calculator: Determine the exact cost of operating the heater. Input your cost per KW·Hr and the controller displays total KW·HRs consumed, total cost of operation, and total hot water usage (shown in gallons or liters).
Checkmark Temperature Control: Set the digital display to the desired water temperature in °F or °C. Fully adjustable in 1° increments from 32-194°F (0-90°C). A user adjustable +/- 3° calibration feature provides additional control for superior accuracy.

Full Heater Modulation

Each heating element is switched on/off using a fast acting solid state triac with zero cross over firing control. This switching schema provides full modulation of each heating element, ensuring that the precise amount of heat is added to meet demand. To improve operating efficiency and component longevity, each triac is mounted to a heat sink located on the incoming supply piping so that heat generated by the triac during the switching process is dissipated into the water.

Proper Power Integrity

All Hubbell tankless water heaters, including all 3 phase models, are engineered to operate as a balanced load and operate at 0.999 Power Factor. All Hubbell 3 phase models are designed for 3 wire (3 live, 1 ground) and 4 wire power systems and draw equal current across all conductors to maintain the power integrity of the users electrical system. Hubbell does not recommend the use of heaters that operate as an unbalanced load, as is common with staged heaters designed for star systems (3 live, 1 neutral, 1 ground) that require use of the neutral leg.  All load switching in Hubbell tankless models is performed as zero cross over, eliminating phase angle firing interference and associated EMI issues.

Full Resource Staging

The Hubbell tankless control schema ensures that usage is equalized across all heating circuits. To achieve this, once the controller has calculated the precise amount of kW required, all circuits are energized in a staggered fashion such that each circuit is proportionally and independently energized and then time staggered between circuits. This Full Resource Staging Schema reduces EMI output, increases component longevity, and provides highly accurate and consistent hot water temperatures.  For three phase models, all circuits are fully modulated and synchronized to operate as a balanced load.

Building Management Integration

Remote Control:Ability to remotely enable or inhibit the heating operation of the unit using one of the following two methods:
1. Customer supplied 24VDC signal is user configured for either Inhibit Mode or Normal Operation Mode.
2. Customer supplied volt free contact is user configured for either Inhibit Mode or Normal Operation Mode.

Priority Control: An integrated SPDT potential free dry contact (NO/NC 10A @ 240VAC) energizes when the unit is heating and de-energizes when not heating. This feature is useful when it is desirable to give the water heater priority over another electrical load to ensure that both are not operational at the same time.

Outline Dimensions and Model Selection

3-18 KW Models (2 Element)

3-18kW Models Outline Dimensions

KW Selection Chart
Model Number KW Ratings
240V 220V 208V
R003-2S 3 2.5 2.2
R005-2S 4.5 3.7 3.3
R007-2S 7 5.8 5.2
R009-2S 9 7.5 6.7
R011-2S 11 9.2 8.2
R014-2S 14 11.7 10.5
R016-2S 16 13.4 12
R018-2S 18 15.1 13.5

21-27 KW Models (3 Element)

3-18kW Model Outline Dimensions

KW Selection Chart
Model Number KW Ratings
240V 220V 208V
R021-3S 21 17.6 15.7
R024-3S 24 20.1 18
R027-3S 27 22.6 20.2

Heating Capacity and Amperage Chart

Model No. KW Ratings at Various Voltages Heating Capability in GPM at °F Temperature Rise (°FΔT) Max Amps at 100% output
1 Phase Voltages
240V 220V 208V 40°F ΔT 60°F ΔT 80°F ΔT 100°F ΔT 240V 220V 208V
R003-2S 3     0.51 0.34 0.26 0.20 12.5    
  2.52   0.43 0.29 0.21 0.17   11.4  
    2.25 0.38 0.26 0.19 0.19     10.8
R005-2S 4.5     1.19 0.80 0.60 0.48 29    
  3.78   0.64 0.43 0.32 0.26   17.1  
    3.37 0.57 0.38 0.29 0.23     16.2
R007-2S 7     1.19 0.80 0.60 0.48 29    
  5.88   1.00 0.67 0.50 0.40   26.7  
    5.2 0.89 0.59 0.44 0.35     25
R009-2S 9     1.54 1.02 0.77 0.61 37.5    
  7.56   1.29 0.86 0.64 0.52   34.3  
    6.7 1.14 0.76 0.57 0.46     32.2
R011-2S 11     1.88 1.25 0.94 0.75 46    
  9.24   1.58 1.05 0.79 0.63   42  
    8.2 1.40 0.93 0.70 0.56     39.4
R014-2S 14     2.39 1.59 1.19 0.96 58    
  11.76   2.01 1.34 1.00 0.80   53.4  
    10.5 1.79 1.19 0.90 0.72     50.4
R016-2S 16     2.73 1.82 1.36 1.09 67    
  13.44   2.29 1.53 1.15 0.92   61  
    12 2.05 1.36 1.02 0.82     57.6
R018-2S 18     3.07 2.05 1.54 1.23 75    
  15.12   2.58 1.72 1.29 1.03   68.7  
    13.5 2.30 1.54 1.15 0.92     64.9
R021-3S 21     3.58 2.39 1.79 1.43 87.5    
  17.64   3.01 2.01 1.50 1.20   80.1  
    15.75 2.69 1.79 1.34 1.07     75.7
R024-3S 24     4.09 2.73 2.05 1.64 100    
  20.16   3.44 2.29 1.72 1.38   91.6  
    18 3.07 2.05 1.54 1.23     86.5
R027-3S 27     4.61 3.07 2.30 1.84 112    
  22.68   3.87 2.58 1.93 1.55   103  
    20.25 3.45 2.30 1.73 1.38     97.3
Alternate voltages including 277, 380, 415, 440, 575 and 600 volt available. Please contact us directly for exact KW availability in these voltages.
For 3 phase voltages, please see Hubbell Model TX.

Sizing Formulas

Step 1

KW Requirement:
________ GPM x ________ °FΔT x 0.1465 = ________ KW
Temperature Rise:
________ KW x 6.824 ÷ ________ GPM _________ °FΔT
Flow Rate:
________ KW x 6.824 ÷ ________ °FΔT = __________ GPM

Step 2

Choose the Tankless model with the KW rating which meets the peak demand (GPM) and required temperature rise (°FΔT) for your application.

Step 3

Choose the supply voltage available. Note the total amperage draw of the unit and verify availability.

Voltage De-Rating Factors

Rated Voltage Applied Voltage De-Rating Factor
240 V 230 V 92%
240 V 220 V 84%
240 V 208 V 75%
When the actual supply voltage (applied voltage) is different than the design voltage (rated voltage) the resulting KW output will be affected. Please see the chart for typical voltage de-rating factors, or use the following formula.
(Applied Voltage² ÷ Rated Voltage²) x Rated KW = KW output at applied voltage

Optional Equipment

  • Inlet and Outlet Valve assembly simplifies installation and includes unions, shut offs, check valve, drain ports and pressure relief valve
  • Air separator to clear the incoming cold water of micro air bubbles, sand, dirt and rust. Recommended for use with well water systems
  • Descaler kit simplifies the process of cleaning the heater and removal of mineral deposits
  • For heaters suitable for operation with 3 phase voltage, please see Hubbell Model TX
  • Special construction features available
  • Remote Control Display allows the heater to be installed in a remote location. The 3" x 5" NEMA 4 display enclosure can be located up to 250' from the heater and gives the operator full remote control and monitoring capabilities
  • An ASSE 1070 code compliant Thermostatic mixing valve to increase the amount of hot water available. Valve is 1/2" (-UT) size and adjustable from 80-120°F. Typically used when supplying hot water to multiple lavs from a single water heater.

Please note: optional equipment may impact overall dimensions and weight. Please request submittal drawing from factory.

Search FAQs

Model Tankless Specific Questions

What is the difference between gas & electric tankless water heaters?

The most obvious difference between gas and electric tankless water heaters is the energy source that is used. Gas tankless heaters use either Natural Gas (NG) or Propane (LPG), but also use electricity (120v) to power an internal fan and other controls. Electric tankless heaters operate using only electricity. Electric tankless water heaters operate at higher energy efficiency, in the case of Hubbell the thermal efficiency is 98%+, compared to gas tankless which ranges from Energy Factor ratings of 0.82 to 0.96 depending upon model. Electric tankless is more efficient in large part because gas tankless models operate by burning gas, which is harder to control than electricity and is less efficient due to heat lost in the flue exhaust. Gas heaters require exhaust and/or fresh air intake venting, whereas electric heaters do not. Please note that efficiency and operating cost are two different things, to determine operating cost one must consider their cost of energy and usage in addition to the operating efficiency of the heater. Gas tankless water heaters cost more to purchase compared to electric tankless heaters. When replacing a storage tank type water heater with a tankless heater, it should be noted that both gas and electric tankless require changes to the existing plumbing and wiring of the tank they are replacing. When installing a new gas tankless heater, most installations will require a new/upgraded venting and gas line. When installing a new electric tankless heater, most installations will require upgraded wiring to the heater and replacement of the circuit breakers in the electrical panel. The largest available residential and light duty commercial gas tankless water heater is 199,000 BTU/Hr, but the most common size has an output of about 123,000 BTU/Hr. After factoring for energy efficiency, this is equivalent to roughly 36 kW. By contrast, the largest residential/light duty commercial electric tankless water heater is 27 kW, which has an effective output of 91,000 BTU/Hr. In terms of operation and maintenance, a gas tankless heater is considerably more complicated to maintain and service compared to electric tankless. In addition, an electric tankless heater will provide more accurate and consistent hot water temperature throughout a full range of flow rates compared to a gas tankless heater. However, gas tankless heaters because they are available in larger BTU sizes can provide a higher hot water flow rate/temperature rise for very large installations compared to a standard electric tankless heater.

Will I get instant hot water with a tankless water heater?

This is a common misconception of tankless water heaters. A tankless water heater does heat water on-demand instantly. Just like a tank water heater, it still takes the same amount of time for the hot water to travel through the pipes and flush out the standing water that has cooled down and is already inside the hot water plumbing. No matter what type of heater is installed, it will always take time for the hot water to travel through the plumbing before arriving at the fixture. The length of time it takes always depends on the length of the pipes, the amount of flow through the fixture and the water pressure. In general, a centralized water heater will require the most time to deliver hot water to the fixture, whereas a Point-of-Use water heater will deliver hot water to the fixture in the shortest amount of time.

How is a tankless heater different from a storage tank heater?

A storage tank water heater maintains a tank full of hot water 24/7/365 and will heat water even during periods of no usage in order to make up for standby heat loss. A tankless water heater only consumes power (whether its gas or electric) when there is demand for hot water. They take up significantly less space and typically can be located close to the point of use, thus providing more efficient delivery of hot water. Tankless water heaters provide continuous hot water and never run out as long as the heater capacity is not exceeded.

Does the Hubbell electric tankless water heater restrict water flow?

No. Hubbell electric tankless water heaters do not restrict water flow. Other brands may incorporate a flow restrictor device within their tankless heater or require a flow restricting device be installed in the plumbing or fixture itself as a method for controlling temperature. This is not the case for Hubbell electric tankless water heaters.

Is Tankless right for my application?

It depends. Due to the relative small physical size of a tankless water heater compared to a storage tank water heater, a tankless option can be advantageous from a space and weight saving perspective and can sometimes be installed closer to where you want hot water. Tankless water heaters do not store heated water like a storage type water heater; they only heat water as there is demand and therefore must be sized to meet the maximum flow and temperature rise for the application. Therefore, before proceeding with a tankless heater you must carefully understand your application and review your available power. Hubbell offers a wide range of electric tankless marine heaters go to Electric Tankless for details. It is critical that before choosing to go tankless you have carefully considered all of the factors that sometimes make the tankless option more complicated and risky compared to a storage type water heater.

General Questions

Where can I purchase a Hubbell water heater?

There are numerous ways to purchase a Hubbell water heater depending upon the model you desire and your geographic location. The easiest way is to contact Hubbell directly at 800-647-3165 and ask for the sales department where you will be directed to either our local representative or our order entry department for quick and easy ordering.

Where can I purchase replacement parts?

Parts are available for your Hubbell water heater direct from the factory. Please call 800-647-3165 and ask for our parts department. Please have your model and serial number handy.

I don't see the size or feature I need, what do I do?

Hubbell has more than 35 product families available in over 4,000,000 configurations. There are numerous features, configurations and ratings we provide but for practical reasons are are not listed in the sales brochure. If you have a specific requirement and you do not see it in the brochure, please contact a Hubbell Sales Engineer...chances are we have what you need.

What should I know about Legionella disease?

Legionella is the bacteria responsible for Legionnaire’s Disease, an acute bacterial infection of the lower respiratory tract. This bacterium was first identified in 1977 by the Centers for Disease Control as the cause of an outbreak of pneumonia that caused 34 deaths at a 1976 American Legion Convention in Philadelphia. Pontiac Fever is a less severe, non-pneumonia, flu-like disease that is associated with and likely caused by Legionella bacteria. Legionella is a fairly common water bacterium and has been found to exist widely in many surface water sources including lakes, rivers, streams and ponds. It can also be found in ground water sources and some soils. At the levels found in these naturally occurring sources it typically does not pose a threat to public health. When the bacterium enters a domestic water system it can find an ideal host environment of warm water temperatures (105-115°F), stagnant water areas (isolated storage tanks and dead-end piping legs) and ample food sources (sediment, scale, deposits and biofilm). Under these conditions Legionella can rapidly colonize, forming higher concentrations that can pose the public health threat of Legionnaire’s Disease. There are many methods of controlling colonization of Legionella bacteria. However, a widely accepted and preferred method is to maintain the hot water system storage temperature continually at or above 140°F. Unfortunately, the elevated temperature necessary to minimize the growth of and kill Legionella bacteria has the potential to cause serious thermal shock and scalding injuries. As such, many plumbing engineers will specify that the water heater be set to maintain water temperatures at 140°F or higher to reduce the risk of Legionella, but then specify the appropriate mixing valve to ensure safe delivery of hot water to the fixtures. For a more thorough discussion of Legionella please go to here and the following link to the US Department of Labor OSHA information regarding Legionnaires’ Disease OSHA here

My question is not found in these FAQ’s, where do I look next?

Check out the Hubbell Product Center at Here for a complete listing of all technical documentation available by model. Get easy access to Installation, Operation & Maintenance manuals, Sales Brochures, Service Bulletins, Wiring Schematics, Parts Breakdowns and various other technical documents related to the full line of Hubbell water heaters. Or, if you prefer, please call us at 800-647-3165 and ask to speak to a Sales Engineer.


Many of our products literature is available online for download. To open these files, a PDF viewer is required. If you do not have one, Adobe provides Acrobat Reader free of charge for viewing only. Use this link to download Acrobat Reader. You may also choose to download the file to your PC for future reference or printing. On most operating systems, simply right-click on the links below, choose "Save target as..." or "Save link as...", choose a location and it will save the document to your computer for future reference.

Tankless Specific Questions

Where can I purchase replacement parts?

Parts are available for your Hubbell water heater direct from the factory. Please call 800-647-3165 and ask for our parts department. Please have your model and serial number handy.

For Further Assistance Please Contact a Hubbell Tech Support Rep.

Tech Support Email

Hubbell Heaters
45 Seymour Street
P.O. Box 288
Stratford, CT 06615-0288
Tel: 203-378-2659
Fax: 203-378-3593
Product Center
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