Differences Between Commercial Tankless Water Heaters and Residential Water Heaters

If you own or manage a commercial facility like a hotel or multifamily property, you know that you can go for a singular water heating system for the entire facility, or individual water heaters for each unit. If you have decided to go for a singular water heating system, you may not fully know the major differences between a tankless water heater that is specifically engineered for commercial use, and a residential one that is scaled up haphazardly for larger, singular use. This brief article will cover the differences you should look out for.

What Are Commercial Tankless Water Heaters?

These are tankless water heaters that are specifically engineered to handle large, commercial loads. This may seem like a small difference. However, having a water heater designed to handle large loads can have significant impact on operational expenses, maintenance hassles, and downtime. 

“Large” loads refer to gargantuan needs like 20-35 gallons per day per occupant in a hotel (source). 

What are Residential Tankless Water Heaters?

There are two definitions of residential water heaters which can make this confusing. In most cases, “residential tankless water heaters” refers to the single-unit products that are usually found in people’s homes. If a facility like a multi-family apartment has individual water heaters for each of its units, you will find these residential tankless water heaters. These are not the tankless water heaters we are referring to in this article.

When it comes to singular water heating systems for large properties, there are various products or tankless water heating systems that were conceptualized for individual use. These units are either combined in a rack system or upgraded haphazardly to be able to meet commercial loads on paper. These are the “residential tankless water heaters” scaled up for commercial use that we refer to in this article.

How to Spot the Differences Between Commercial Tankless Water Heaters and Residential Tankless Water Heaters?

1. Commercial Tankless Water Heaters are ASME HLW Rated:

Spot such certifications for commercial tankless water heaters above 200,000 BTUs/hr.

2. Factory-Tested As an Entire System.

You should always find out if the specific commercial water heating system being sold to you was tested as a complete system. Residential tankless water heaters scaled up for commercial work are not tested as a composite system. Only their individual units are. Hence, there is no way to tell if the composition of individual units will work efficiently for your property.

3. Designed To Handle Millions of Thermal Cycles With 316L Stainless Steel Heat Exchangers

If you were to upgrade from a car to a truck, you would expect a more powerful engine, right? Same concept here. You should expect tankless water heaters designed for large, commercial loads to have a significantly more powerful heat exchanger (the water heater’s “engine”) than a residential tankless water heater meant for smaller loads.

4. No Warranty Limitations on Thermal Cycles, Run Hours, or Recirculation.

For residential tankless water heaters are simply scaled up haphazardly to meet commercial loads, manufacturers place warranty limitations on thermal cycles, run hours, or recirculation because they know that the system is not designed to handle large, continuous loads without major faults. If you have a commercial property, you should not settle for a warranty that limits your usage.

5. Masterless Controls.

Commercial water heating systems need to be intricately connected to other elements of the property’s built environment. Hence, they should be designed in a way that single-point failures do not lead to complete system downtime. Residential water heaters scaled up for commercial do not have this feature in their design and lead to lack of hot water for routine maintenance events and single point failures.

6. Don't Need Annual Descaling.

Scale formation is a real concern for tankless water heaters. Especially ones that heat thousands of gallons of water. Commercial tankless water heaters should be engineered to mitigate scale formation on their own without needing annual flushing.

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