Best Commercial Tankless Water Heaters for Businesses
Answering the question “which commercial tankless water heater is best for my needs?” this guide highlights five top options, focusing on efficiency, installation flexibility, and reliable hot water delivery. These models suit small to medium commercial setups, multi-dwelling properties, or light-industrial uses. Read on to compare who each unit is best for, and where trade-offs matter.
| Product | Best For | Output (GPM) | Fuel | Notes |
|---|---|---|---|---|
| Rinnai CX199iN | Medium commercial spaces; indoors or outdoors | 11.1 | Natural gas or propane | Versa Vent; Smart Sense control; 97% efficiency |
| Westinghouse APOLO Indoor 180,000 BTU | Small to mid-size facilities; indoor installation | 7.9 | Propane or natural gas | Remote and LED temp control; ±1°F stability |
| Westinghouse APOLO Outdoor 180,000 BTU | Outdoor installations; easier access for venting | 8.1 | Natural gas | Outdoor-ready; remote control; ±1°F stability |
| MIZUDO Gas Indoor 7.9 GPM | Residential-to-light commercial indoor use | 7.9 | Natural gas | CSA certified; sealed combustion; multiple safety features |
| Westinghouse APOLO Indoor 7.9 GPM | Indoor light commercial; versatile use | 7.9 | Natural gas | Smart temp control; LED/status indicators |
Rinnai CX199iN Condensing Tankless Water Heater
The Rinnai CX199iN is a versatile condensing unit rated at 199,000 BTU with an 11.1 GPM capacity, suitable for indoor or outdoor installation using Versa Vent. It supports either propane or natural gas via a Smart Sense control system. This model emphasizes high efficiency (97%) to reduce operating costs. It can be paired with a recirculation kit for faster hot water delivery.
- Best for: Medium-demand commercial spaces needing flexible installation and high efficiency.
- Why selected: Strong BTU rating, adaptable venting, and energy savings through Smart Sense control.
- Caution: Outdoor installation requires the RX-OVC vent cap for weather protection.
Westinghouse Tankless Water Heater Propane Indoor (Apoio) 7.9 GPM
This Westinghouse model delivers up to 7.9 GPM with 180,000 BTU, designed for indoor installation and propane fuel. It offers smartphone app or LED panel temp control and a flow servo that maintains water temperature around a tight ±1°F. It’s a compact, powerful choice for small to mid-size facilities with multiple fixtures.
- Best for: Indoor setups needing precise temperature control at a compact size.
- Why selected: Strong flow for multiple outlets; user-friendly temp management.
- Caution: May be undersized for larger facilities with simultaneous high-demand usage.
Westinghouse Natural Gas Tankless Water Heater Outdoor
This outdoor Westinghouse unit furnishes up to 8.1 GPM with 180,000 BTU and is designed for outdoor installation with a remote control panel inside. It features a temperature servo to keep water within about ±1°F, suitable for facilities that can accommodate exterior mounting and venting.
- Best for: Outdoor-ready projects where venting and space inside are constraints.
- Why selected: High outdoor output and convenient remote operation.
- Caution: Outdoor durability depends on climate protection and weatherproofing measures.
MIZUDO Natural Gas Indoor Tankless Water Heater
The Mizudo unit provides up to 7.9 GPM with 180,000 BTU, designed for indoor direct-vent installation. It emphasizes a sealed combustion system and CSA certification, along with features such as freeze protection, dry-fire safeguards, auto-relight, and fault detection. It supports consistent hot water with minimal temperature fluctuation for residential to light commercial use.
- Best for: Indoor residential-to-light commercial projects needing strong safety features.
- Why selected: CSA-certified with comprehensive safety protections.
- Caution: Sealed-combustion units require proper venting and maintenance to maintain efficiency.
Westinghouse Natural Gas Indoor APOLO 7.9 GPM
This indoor APOLO model provides 7.9 GPM with 180,000 BTU and emphasizes smart temp control with a LED display and app-based adjustments. It is suited for light commercial use and homes or offices needing reliable hot water with clear status indicators.
- Best for: Indoor light-commercial settings and spaces requiring easy remote monitoring.
- Why selected: Clear temp control and integration with mobile or LED interfaces.
- Caution: May not meet higher simultaneous hot water demands in larger facilities.
Buying Guide: What to Consider When Choosing a Commercial Tankless Water Heater
- Hot water demand: Calculate peak GPM needs for all fixtures that may run at once. Choose a unit with a comfortable margin above this demand to avoid pressure or temperature drops.
- Ventilation and installation: Indoor systems require venting and proper clearance. Outdoor units simplify venting but need weather protection and corrosion resistance considerations.
- Fuel type and availability: Decide between natural gas and propane based on on-site fuel infrastructure, delivery stability, and cost projections.
- Efficiency and operating costs: Condensing models generally offer higher efficiency, reducing energy use and operating costs over time.
- Control and integration: Look for models with easy temperature control, remote monitoring, and compatibility with existing building management systems if needed.
- Safety features: Consider dry-fire protection, auto-relight, freeze protection, and fault detection to minimize downtime and prevent damage.
- Maintenance requirements: Access for service, ease of part replacement, and venting maintenance can affect long-term reliability and costs.
Frequently Asked Questions
- What is a tankless water heater’s main advantage for a business?
They provide on-demand hot water, potentially saving energy by avoiding standby losses and delivering consistent temperatures during peak usage. - How do I determine the right GPM for my facility?
List all fixtures that may run simultaneously, estimate their flow rates, and add a buffer for peak demand; then select a unit with higher GPM capacity or plan for staged installations. - Are outdoor tankless heaters suitable for all climates?
Outdoor models can work in many climates but require weatherproofing, corrosion-resistant materials, and protection from extreme conditions. - Do I need professional venting for a tankless system?
Yes. Proper venting is essential for safe operation and efficiency, especially for sealed combustion units and outdoor-to-indoor installations. - What safety features matter most in a commercial unit?
Look for freeze protection, dry-fire protection, auto-relight, and fault-detection systems to minimize downtime and risk. - Can I pair these heaters with a recirculation system?
Some models support optional circulation kits to improve hot water delivery times and efficiency; verify compatibility with your chosen unit.