Rinnai N1300e 47 kW External Condensing Gas Water Heater | 35 L/min

Rinnai N1300e external condensing gas water heater

The Rinnai N1300e external condensing gas water heater is a high-output commercial continuous-flow water-heating solution designed for properties that require reliable hot water without relying on a traditional large storage cylinder.

Part of Rinnai’s N Series commercial water heater range, the N1300e is designed for external installation and uses condensing technology, automatic output modulation and a stainless-steel primary heat exchanger.

The N1300e provides a maximum water flow rate of approximately 35 litres per minute under the specified operating conditions and is designed for applications with significant and variable hot-water demand. Rinnai identifies the external model as REU-N2635WC.

Key Features

• Rinnai N1300e external commercial water heater
• Approximately 47 kW gas input/output class for the N1300 configuration
• Up to 35 L/min water flow
• Condensing instantaneous water-heating technology
• External wall-mounted installation
• Natural gas configuration
• LPG conversion option where applicable
• Stainless-steel primary heat exchanger
• Low-NOx burner technology
• Automatic output modulation
• 13:1 turndown ratio
• Electronic ignition
• Direct forced-exhaust system
• Powerful fan motor
• Cascade capability
• Suitable for commercial and high-demand hot-water applications

Rinnai describes the N Series as a commercial continuous-flow range featuring a stainless-steel primary heat exchanger, Low-NOx technology, 13:1 turndown and cascade capability.

What Is the Rinnai N1300e?

The Rinnai N1300e is an externally installed commercial condensing instantaneous gas water heater.

Unlike a conventional storage water heater, it heats water as it passes through the appliance. This provides continuous hot-water production without requiring the appliance itself to store a large volume of hot water.

The N1300e can therefore be considered for commercial installations where hot-water demand changes throughout the day.

Typical applications include:

• Hotels
• Restaurants
• Commercial kitchens
• Care facilities
• Sports centres
• Gyms
• Leisure facilities
• Schools
• Offices
• Agricultural buildings
• Apartment developments
• Large residential properties
• Industrial facilities

The correct system size should always be determined from the building’s calculated hot-water demand, incoming water temperature, required temperature rise, water pressure and simultaneous outlet usage.

47 kW Commercial Water Heating

The N1300 is a high-output commercial water heater within Rinnai’s N Series.

The EuroFuelSupply product configuration lists approximately 47 kW for the N1300e, while Rinnai’s technical documentation identifies the N1300e as the external REU-N2635WC model.

This output makes the N1300e suitable for applications where a standard domestic gas water heater would not provide sufficient hot-water production.

For larger installations, multiple Rinnai N Series appliances can be cascaded to increase overall system capacity.

Up to 35 L/min Water Flow

The Rinnai N1300e can deliver up to approximately 35 litres per minute under the manufacturer’s specified conditions.

Rinnai’s current product information specifically states that the N1300 can produce up to 35 L/min. The N Series also includes a flow-booster function that can allow higher volumes when the required dynamic water pressure and temperature conditions are met.

Therefore, the actual flow rate should be determined from:

• Incoming water temperature
• Required outlet temperature
• Dynamic water pressure
• Gas supply
• Number of simultaneous outlets
• System configuration

The 35 L/min figure should be treated as the manufacturer’s maximum specified flow rather than a guaranteed flow at every temperature rise.

Continuous-Flow Hot Water

The N1300e heats water as it is required.

This continuous-flow design can provide several advantages for commercial applications:

• Hot water available on demand
• No large storage cylinder required for the appliance
• Reduced standby losses associated with storing hot water
• Automatic output modulation
• High-flow performance
• Suitable for variable demand
• Scalable through cascade installation

The appliance should be sized by a qualified installer according to the property’s actual peak demand.

External Installation

The N1300e is specifically designed for external installation.

Rinnai’s technical documentation distinguishes the N1300e external model from the N1300i internal model and identifies the external unit as REU-N2635WC.

External installation can be particularly useful when:

• Internal plant-room space is limited
• A commercial building requires external plant
• Several water heaters need to be cascaded
• Internal flue arrangements are difficult
• The installation design benefits from external equipment

The installer must follow Rinnai’s current clearance, gas, water, flue, condensate and electrical requirements.

Condensing Technology

The Rinnai N1300e uses condensing water-heating technology.

Condensing operation is designed to recover additional heat from combustion gases before they are discharged, helping improve thermal efficiency compared with conventional non-condensing systems under suitable operating conditions.

Actual efficiency depends on:

• Water temperature
• Return temperature
• Incoming cold-water temperature
• Hot-water demand
• Gas type
• Operating conditions
• System design

Avoid assuming that the same efficiency percentage applies under every operating condition.

Stainless-Steel Heat Exchanger

The N Series incorporates a stainless-steel primary heat exchanger.

Rinnai highlights the stainless-steel heat exchanger as a durability feature of its N Series commercial water heaters.

This is particularly relevant for commercial applications where the water heater may operate frequently throughout the day.

13:1 Turndown Ratio

The Rinnai N1300e incorporates a 13:1 turndown ratio.

This allows the appliance to modulate its output as hot-water demand changes rather than simply operating at one fixed output.

Rinnai identifies the 13:1 turndown ratio as a key feature of its N Series commercial water heaters.

For commercial buildings, modulation can be particularly useful because hot-water demand can vary considerably between peak and low-use periods.

Low-NOx Burner Technology

The Rinnai N Series incorporates Low-NOx burner technology.

Rinnai states that its patented burner technology is designed to reduce nitrogen oxide emissions while maintaining the required water-heating performance.

The current EuroFuelSupply page lists a Low-NOx value of 27.4 mg/kWh for the N1300e configuration.

For compliance purposes, installers should use the applicable current manufacturer documentation and local regulations for the exact supplied model.

Natural Gas and LPG

The EuroFuelSupply page offers the N1300e in a natural-gas configuration, with an LPG conversion option.

The product page currently lists:

• W1300E(N)-NAT — Natural Gas
• W1300E(N)-LPG — Natural Gas appliance supplied with LPG conversion kit

For accuracy, the customer-facing option name should make it clear that the LPG version involves conversion of the supplied natural-gas appliance.

LPG conversion must be performed by an appropriately qualified gas engineer in accordance with the manufacturer’s instructions and applicable local regulations.

Commercial Applications

The Rinnai N1300e is designed for commercial and high-demand hot-water applications.

Hotels

Hotels can experience simultaneous demand from guest bathrooms, kitchens, laundry facilities and other services.

The N1300e can be considered as part of a properly sized commercial hot-water system.

Restaurants and Commercial Kitchens

Restaurants require reliable hot water for food preparation, washing and cleaning.

Continuous-flow water heating can provide hot water as demand occurs.

Gyms and Leisure Centres

Showers can create substantial peak hot-water demand.

The N1300e can be used individually or as part of a cascade arrangement where higher capacity is required.

Care Facilities

Care homes and similar facilities can have consistent hot-water requirements throughout the day.

A professionally designed N Series installation can be configured according to the property’s demand profile.

Schools

Schools can have concentrated periods of hot-water demand, particularly around sports and changing-room facilities.

Apartment Developments

The N1300e can be considered for centralised commercial hot-water systems in multi-unit developments.

Cascade Installation

One of the strongest commercial features of the Rinnai N Series is its ability to operate in cascade systems.

Multiple water heaters can be connected to increase total hot-water production.

Cascade configurations are useful when:

• Hot-water demand is very high
• Multiple outlets operate simultaneously
• Plant-room redundancy is important
• Demand varies significantly
• The project may require future expansion

Rinnai states that N Series water heaters can be cascaded to meet very high hot-water demand.

Flue Flexibility

The N Series incorporates a powerful fan motor and flue-management components designed to provide installation flexibility.

Rinnai states that N Series systems can achieve flue runs of up to 46 metres using the specified 80/125 concentric flue arrangement, subject to the applicable installation configuration.

Flue length, termination, bends and common-flue arrangements must always be checked against the current Rinnai installation documentation.

Temperature Control

Rinnai’s N Series is designed to deliver temperature-accurate hot water.

Rinnai states that its water heaters can deliver hot water at approximately ±1°C of the heater set point under specified conditions.

The exact delivered temperature depends on:

• Set point
• Water flow
• Incoming water temperature
• System pressure
• Controller configuration
• Installation conditions

Technical Specifications

Rinnai’s current documentation confirms the external N1300e model, maximum 35 L/min flow and condensing instantaneous configuration.

Dimensions and Installation

The current EuroFuelSupply page identifies the N1300e as a compact external wall-mounted appliance weighing approximately 28 kg.

The installation location should provide sufficient clearance for:

• Servicing
• Gas connections
• Water connections
• Condensate drainage
• Flue termination
• Airflow
• Maintenance access

Always use the current Rinnai installation manual for exact dimensions and required clearances.

Why Choose the Rinnai N1300e?

The Rinnai N1300e 47 kW external condensing gas water heater combines commercial output with a compact external installation format.

Key benefits include:

• Up to 35 L/min water flow
• Commercial continuous-flow operation
• External installation
• Condensing technology
• Stainless-steel heat exchanger
• Low-NOx burner technology
• 13:1 modulation
• Natural-gas configuration
• LPG conversion option
• Cascade capability
• Temperature-accurate hot-water delivery
• Flexible commercial installation
• Rinnai N Series technology

Installation Requirements

The N1300e is a professional commercial gas appliance.

Installation should be carried out by an appropriately qualified gas/HVAC professional.

The installer should verify:

• Gas type
• Gas supply pressure
• Gas pipe sizing
• Water pressure
• Required flow rate
• Incoming water temperature
• Required outlet temperature
• Condensate drainage
• Flue arrangement
• Electrical supply
• Outdoor clearances
• Local gas regulations
• Applicable building requirements

The exact Rinnai installation manual should be followed for the supplied configuration.

Sizing a Commercial Hot-Water System

Selecting the correct water heater requires more than looking at the maximum litres-per-minute specification.

A professional system design should consider:

1. Number of outlets
2. Simultaneous demand
3. Incoming cold-water temperature
4. Required hot-water temperature
5. Required temperature rise
6. Dynamic water pressure
7. Gas supply
8. Recirculation requirements
9. Pipework losses
10. Operating schedule

For very large commercial projects, multiple N1300e units can be cascaded rather than relying on a single appliance.

Frequently Asked Questions

What is the Rinnai N1300e?

The Rinnai N1300e is an external commercial condensing instantaneous gas water heater from the Rinnai N Series. Its manufacturer model reference is REU-N2635WC.

How powerful is the Rinnai N1300e?

The current EuroFuelSupply product specification identifies the N1300e as a 47 kW commercial water heater configuration.

How many litres per minute does the N1300e deliver?

Rinnai states that the N1300 can deliver up to 35 litres per minute under the specified conditions.

Is the Rinnai N1300e external?

Yes. The N1300e is the externally installed version of the N1300, while the N1300i is the internal version.

Is the Rinnai N1300e a condensing water heater?

Yes. Rinnai identifies the N1300 as a condensing instantaneous water heater with automatic output variation.

Can the N1300e run on LPG?

The EuroFuelSupply configuration provides an LPG conversion option. The appliance is supplied in the natural-gas configuration and must be converted according to the manufacturer’s instructions by an appropriately qualified engineer.

Can the N1300e run on natural gas?

Yes. The current product page provides a natural-gas configuration.

Does the Rinnai N1300e have Low-NOx technology?

Yes. Rinnai identifies Low-NOx burner technology as a feature of the N Series.

Does the N1300e have a stainless-steel heat exchanger?

Yes. Rinnai identifies a stainless-steel primary heat exchanger as a key N Series feature.

Can multiple N1300e water heaters be connected?

Yes. Rinnai states that its N Series appliances can be cascaded to provide greater hot-water capacity.

Is the N1300e suitable for hotels?

It can be suitable for hotels where its calculated hot-water output meets the property’s demand. Larger hotel projects may use multiple units in cascade.

Is the Rinnai N1300e suitable for commercial kitchens?

Yes. It can be considered for commercial kitchens and other applications requiring substantial continuous-flow hot water, subject to correct system sizing.

What is the Rinnai N1300e model number?

The external N1300e is identified by Rinnai as REU-N2635WC.