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Products Electric Packaged Instantaneous Circulation

Packaged Instantaneous Circulation Water Heater

Hubbell Signature CR

Full kW selection in all voltages

Single or Three Phase

Use for domestic water and boiler applications

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Packaged Circulation Solutions


Instantaneous water heater for naval, marine, and industrial applications

The Hubbell Signature CR is a highly reliable and easily maintained water heater designed for continuous operation in a commercial or industrial application. Each heater is constructed to meet the specific requirements of your system and is available in a full array of operating controls, materials, and design styles. Its compact, highly efficient design takes up minimal floor space, reduces operating costs, and is factory packaged with all operating controls.



Engineered for your specific application to meet your exact needs

Full selection of materials and controls to meet even the most demanding application

• Constructed with high grade materials to ensure long operating life
• Turn-key package is simple to specify and operate
• Factory wired electrical controls provide trouble-free installation and operation
• Instantaneous design reduces standby heat loss and lowers operating costs


Process systems, wash downs, aquariums, heat pump back up, swimming pools, high-powered boiler systems, freeze protection, shipboard, and much more.


Hubbell CR Model Standard Equipment
Hubbell CR Model Electrical Operating Controls
Hubbell CR Model Dimensions
Hubbell CR Model Options
Hubbell CR Model Optional Equipment


How does my water heater ship?

All Hubbell storage type water heaters ship via common carrier and are classified by the Commodity Classification Standards Board under National Motor Freight Classification (NMFC) class 100. Each water heater is palletized and wood crated. All Hubbell tankless water heaters, when transported using common carrier, ship class 77.5. To provide the lowest transportation cost, in most cases the shipment is made on Hubbell’s account and the freight cost is added to the invoice, commonly referred to as “Pre pay and add”. For very large shipments, the most economical method (LTL or Dedicated Truck) for transporting the water heaters to the final destination will be analyzed by Hubbell's transportation department.

The heater will be installed in Canada, what is CRN?

All provinces of Canada have adopted the ASME Code and require vessels to be stamped with a provincial registration number in addition to the ASME symbol and National Board stamping. Before construction begins, one requirement has to be met in all provinces of Canada. We must submit blueprints and specification sheets in triplicate of all designs for approval and registration by the chief inspector of the province in which the vessel is to be used. After the chief inspector receives the drawings, they are checked by an engineer to determine their compliance with the Code and also with provincial regulations. A CRN number is assigned and must be stamped on the vessel in addition to the ASME symbol and National Board stamping. Once the design has been approved and registered, any number of vessels of that design can be built and used in the province where it was approved. This process is repeated for each province. The Canadian provinces also require their own manufacturer's affidavit form, with the registration number and the shop inspector's signature on the data sheets. Finally, when a vessel is delivered to a purchaser in Canada, an affidavit of manufacturer bearing registration number and the signature of the authorized shop inspector must be sent to the chief inspector of the province for which it is intended.

What third party approvals are available?

The Hubbell water heater is built to both US and Canadian Standards under UL1453 (water heating only) file KSBZ.E239672 or UL834 (boilers and water heating) file BDJS.E51660. In addition, the Hubbell pressure vessel storage tank is built and stamped to ASME and National Board Registered. Other approvals are available upon request at the time of quoting, including CRN (Canadian Registration Number), NR-13 (Brazilian Regulation Standard Boilers and Pressure Vessels), ABS (American Bureau of Shipping), SASO (Saudi Arabia Standards Organization) and others. Please consult with your Hubbell Sales Engineer to discuss your third party approval requirements.

Are parts available from the factory?

Yes. All replacement parts for the Hubbell water heater are available from the factory. Please call 800-647-3165 and ask for our parts department. Please have your model and serial number handy. Most parts are in stock and orders placed before noon typically ship same day. However, it should be noted that the heating element component is typically not a stock item, with delivery times ranging from 2 to 10 weeks depending upon the design, it is recommended that you consider having a replacement heating element on hand if your application is critical.

What type and size relief valve should be installed on my equipment?

The type of relief valve to be installed depends on the intended purpose of the equipment (heater or storage vessel), the medium (steam, air/gas, or liquid), the design temperature of the medium, the vessel code of construction (ASME Section I, IV, or VIII), and local plumbing codes. Local plumbing code take precedence. For more information see the following PDF flowchart here. The sizing of a relief valve depends on the desired operating pressure (not to exceed the rated pressure of the vessel), the type of relief valve (applicable ASME Code compliance as determined above), the medium in the vessel, the required relieving capacity (based on heat input, mass flow rate, or volumetric flow rate), and the relief valve manufacturer's specifications. When supplied with the above information, Hubbell can recommend a manufacturer's model and size.

Is this model approved by Massachusetts?

For the current listing of all Hubbell models approved by the Massachusetts Board of Plumbers and Gas Fitters please see the chart below or visit the website directly at
MA Plumbing Approval NumberHubbell ModelExpiration Date
P3-0914-61HD, J, V, PS, SLN, T9/3/2017
P1-1114-201EMV, CR, R, JTX, ETX, TX11/5/2017
P3-0813-66CE110, SE, E, HE, SH, H8/7/2016
G1-0813-4GX, DGX, JBX, JGX, CX8/7/2016

Is 277 volt 3 phase voltage available for a water heater?

For all water heaters 277V is only an available option in 1PH, not 3PH. The 277V 1PH voltage is a derivation of your existing 480V 3Ph power. Where 480V is the line to line voltage on a 3 phase system and 277V is the voltage from any one of these lines to neutral, thus making the 277V power available in 1PH only.

What is the R value of a Hubbell water heater?

Hubbell uses a blown-in polyurethane foam insulation for all cement lined water heaters and tanks up to 150 gallon capacity. This insulation has an R value of 7.2 per inch. Most Hubbell tanks have a minimum of 2 inches of insulation resulting in an R value of 14. Certain models are available either standard or as an option with 3 inch insulation and therefore have an R value of 21. Large storage water heater tanks over 150 gallon capacity and custom made stainless steel or alloy tanks have either 2" or 3" fiberglass insulation with an R value of 3.5 per inch.

Why Hubbell recommends 300 series versus duplex stainless steel?

While it is true that duplex stainless steel typically offers higher strength and resistance to Stress Corrosion Cracking (SCC) and chloride corrosion compared to austenitic (300 series) stainless steel, there are other factors that ultimately make it a less desirable choice compared to 300 series stainless steel. Duplex stainless steel makes up only 1% of the stainless steel market making it less readily available and higher cost especially in flanges, fittings and formed parts such as tank heads. While it is commonly stated that this added expense is offset by the ability to use material that is thinner due to the higher strength, this only applies to very large tanks where a reduction results in using a lower common plate thickness. As an example, a thickness reduction of 25% for a tank that is 3/16" thick in 300 series stainless steel still results in using the common 3/16" thick plate size in duplex stainless steel. The higher strength of duplex also has the negative result of decreased formability and machinability, adding cost to the fabrication and production process. In terms of welding, duplex stainless steel presents many problems in maintaining the proper two phase mixture which commonly leads to issues in the Heat Affected Zone (HAZ) such as loss of corrosion resistance, toughness, and post-weld cracking. This is true in all duplex stainless steel welding processes including TIG, MIG and Laser. By comparison the process of welding austenitic stainless steel is much more forgiving. The main weakness of austenitic stainless steel is its susceptibility to Stress Corrosion Cracking (SCC) and chloride corrosion. Three factors that all must all be present cause this type of corrosion: elevated heat, the presence of chlorides, and residual stresses. In water heaters elevated heat and the presence of chlorides cannot be controlled. However, post-weld heat treating in a vacuum furnace followed by cooling in an inert atmosphere relieves the residual stresses in austenitic stainless steel tanks and therefore eliminates the susceptibility to this corrosion. For this reason, this post-weld heat procedure is performed on all Hubbell stainless steel tanks. The heat treating process is highly controlled and verifiable, unlike the difficult to control process of welding duplex stainless steel. Therefore, Hubbell offers stainless steel tanks fabricated from the 300 series (typically Type 304L or 316L) only, as this is a far more proven and verifiable material and fabrication process which will result in longer tank life. Of course, an alternative option is to specify the Hubbell cement lined steel tank which also provides a considerably longer life and is a more economical solution compared to duplex stainless steel and 300 series stainless steel.

Do Hubbell water heaters qualify as Low Lead?

Yes, all Hubbell water heater models qualify as meeting the low lead requirements of the “Reduction of Lead in Drinking Water Act” amendment to the “Safe Drinking Water Act” (SDWA) Section 1417(d) effective as of January 4, 2014. Hubbell certifies that its water heaters meet the following requirements of the SDWA and therefore are qualified and certified as Low Lead : (a)Hubbell water heater do not contain more than 0.2 percent lead with respect to solder and flux (b)Hubbell water heaters do not contain more than a weighted average of 0.25 percent lead with respect to all wetted surfaces of the water heater

What is the difference between solid-state and electromechanical relays?

Depending on the application, one switch may be more advantageous than the other. Please refer to this article to read more about the differences between solid-state and electromechanical relays.

How do I prepare my water heater for long term storage?

The water heater must be stored in the orientation of intended use (vertical, horizontal). The recommended ambient air temperature range is between 50 and 105 degree F and not exceeding 65% Rh. Under no conditions should the unit be subject to freezing temperatures. The unit is intended to be stored indoors, protected from the elements. Desiccant material should be inserted into the electric control panel and heating element terminal house (if applicable). Prolonged storage will require periodic inspection of desiccant. For cement lined tanks only, place approximately 10 gallons of water in the tank before closing and sealing all openings to ensure a humid atmosphere for the lining is maintained. Cap and seal all openings and tank tappings and/or flanges. Provide the necessary protection to ensure the tank and all accessories are protected from physical contact that could result in damage. Shrink wrapping or other suitable protective plastic may be applied to the exterior. Start up and installation guidelines must be followed, with particular attention to testing of the electric heating element.

What sheath material is best suited for heating potable water?

There are two materials that are commonly accepted as appropriate for use as heating elemenents in potable water, copper and incoloy 800. The advantage of copper is that it has better heat transfer characteristics, and it is lower cost. So with the copper element, more heat energy can be output by a given design (higher watt density) without over heating the element, as it transfer more efficiently to the water, keeping the sheath temp low at even higher watt densities. In comparison, incoloy 800 has a significantly higher melting point and oxidation temp. It is also generally more corrosion resistant. The practical benefit of of using incoloy in potable water beyond corrosion resistance, is that because of the material's ability to withstand higher temperatures, when scaling occurs and insulates the elements, copper may melt or break down (fail), whereas incoloy can actually dry out the scale, causing it to crack and fall off the element. So you will still get scale buildup, but as it insulates the elements the incoloy is likely to last much longer.

What fluids can I heat with the model CR circulation heater?

The Hubbell CR model circulation heater is commonly used in applications heating industrial process water, potable domestic water, water glycol mixtures, water ethylene glycol mixtures, seawater, demineralized water and RO or DI water. Additional fluids that can be heated by the Hubbell CR circulation heater include oils, sugars and others, please consult a factory sales engineer for details. It should be noted that a Hubbell sales engineer will help to select the appropriate materials of construction and operating features necessary for the proper operation of the model CR circulation heater in your application.

What is watt density?

The Hubbell electric heating element also referred to as the immersion heater, tubular heater, or simply heating element, is the component within the Hubbell CR circulation heater that actually heats the fluid. Watt density is the term which indicates the amount of heat flux emanating from each square inch of the effective heating area (heated surface) of the heating element and is expressed as watts per square inch (W/in2). For most potable water applications, the watt density can range from 50 – 100 W/in2. For corrosive water and other water based fluids the watt density can range from 20 – 50 W/in2. For petroleum oils and higher viscosity fluids with poor thermal conductivity, watt density can range from 6 – 40 W/in2. It should be noted that a Hubbell sales engineer will help to select the appropriate watt density, materials of construction and operating features necessary for the proper operation of the model CR circulation heater in your application.

Can I install this model outdoors?

Yes, as long as you advise the Hubbell sales engineer and specify this in your quote request. The Hubbell CR circulation heater can include construction features making it suitable for a wide range of installation locations including outdoors, but this must be specified when requesting a quote from Hubbell.

Can I install this model in a hazardous location?

Yes, as long as long as you advise the Hubbell sales engineer and specify this in your quote request. You will need to advise your Hubbell sales engineer specific information regarding the hazardous location rating you require for your application including Class (I, II or III), Division (1 or 2), Group (A, B, C or D) and finally the Temperature Class (T1 thru T6). Hubbell carries UL approval for “Control Panels and Assemblies for Use in Hazardous Locations” under file NNNY.E358352 Here and “Control Panels and Assemblies for Use in Hazardous Locations Certified for Canada” under file NNNY7.E358352 Here

Can the heater be used as a boiler or for a space heating application?

Yes, as long as you advise the Hubbell sales engineer and specify this in your quote request. Hubbell builds the CR model circulation heater to either UL1453 (water heating only) under file KSBZ.E239672 or UL834 (boilers and water heating) under file BDJS.E51660. There are slight differences between the two designs, so it is important to know what the application is during the initial quote request phase.

Can it be packaged with a pump, expansion tank or other accessories?

Yes. Hubbell often times integrates pumps and ancillary equipment with a model CR circulation heater to provide a fully packaged and integrated skid system.


Hubbell shall warranty all electrical components against defects in workmanship and material for a period of one (1) year from date of start-up and the pressure vessel for a full five (5) years Non Pro-Rated (Square Optional: full ten (10) years Non Pro-Rated) from date of start-up, provided that the unit is started within three (3) months of date of shipment and installed and operated within the scope of the tank design and operating capability. Each water heater shall be shipped with a complete set of installation and operating instructions including spare parts list and approved drawings.

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