A commercial kitchen, salon, laundry, or apartment building doesn't run on a 50-gallon tank. It runs on recovery rate — how many gallons of hot water the unit can produce per hour, not just how many it stores. Get this wrong and you find out at the worst time: a restaurant losing hot water mid-dinner rush, a laundromat's dryers backed up because the washers are waiting on hot fill, a salon with three chairs and cold rinse water.
What counts as a commercial water heater
Anything sized to serve more than a single household fixture load. In the Portland metro that's mostly:
- High-recovery gas tanks (75–100+ gallon, commercial-grade burners) for restaurants, salons, laundromats, and gyms
- Boiler-fed systems with an indirect storage tank, common in older multi-family buildings and mixed-use buildings downtown and in inner Southeast where a boiler already handles space heat
- Commercial tankless arrays — multiple units manifolded together for buildings that need both high volume and a smaller footprint
- Circulating systems with a dedicated return line, standard in apartment buildings so a tenant on the third floor isn't waiting two minutes for hot water
Which one fits depends on simultaneous demand (how many fixtures could run hot water at once), not square footage.
When you need one
- The current unit can't keep up during peak hours — dishwasher, hand sinks, and mop sink all fighting for hot water at once
- A remodel or tenant improvement adds fixtures (new bar sink, extra shower, laundry hookup) that push the building past what the existing heater was sized for
- An inspector or health department flags recovery rate or temperature at the tap during a permit review
- The building is converting from electric to gas, or from individual unit heaters to a central plant
- Age — commercial units work harder than residential ones and don't last as long as their nameplate suggests
How the visit goes
We start with a load calculation, not a guess: fixture count, peak simultaneous use, and what the space actually does (a salon's demand curve looks nothing like a laundromat's). We check the gas line size and venting, because undersizing the gas supply is the most common reason a "bigger" heater still can't keep up. For boiler-fed setups we look at the indirect tank and whether the boiler itself has the output to support it. Then we walk through options — tank versus tankless array, single unit versus paired units for redundancy — and what each means for install time and shutdown.
Most commercial installs need a permit and inspection, and if the building has multiple tenants or a property manager, we schedule around business hours so you're not closing to install a water heater.
What affects the price
- Recovery rate and BTU input required for the actual load, not the old unit's rating
- Gas line and vent modifications — undersized gas piping is common in buildings converted from one use to another
- Whether it's a straight swap or a system change (tank to tankless, standalone to boiler-fed)
- Access — basement mechanical rooms, rooftop units, and tight commercial kitchen corridors all add time
- Backflow prevention and code-required mixing valves, more often required on commercial systems than residential
- Multi-unit buildings sometimes need parallel systems sized for redundancy so one failure doesn't take down hot water for the whole building
We don't quote off a phone description for commercial work — the load calculation has to happen on site.
What's specific to Portland buildings and water
A lot of Portland's commercial and mixed-use stock is older brick or converted residential buildings in inner Southeast, Old Town, and along the close-in commercial corridors, originally built for a fraction of today's hot water demand. Boilers installed decades ago are often oversized for space heat but never accounted for a modern kitchen or laundry load added later. Portland's water is soft with a mild pH, which is kind to storage tanks and reduces scale buildup compared to harder-water cities — but soft water also runs slightly acidic in places, which shows up as pinhole leaks or fitting corrosion faster in older commercial copper. High-recovery units and any exposed rooftop or exterior components also need to handle a full Willamette Valley winter, including the occasional hard freeze — venting and condensate lines get sized and insulated with that in mind, not just for a mild-year average.
Why Sheltons Construction
We're a licensed Oregon plumbing contractor working the Portland metro day in and day out, on restaurants, salons, laundromats, and apartment buildings as well as houses. Commercial water heater work means pulling the right permit, sizing to an actual load calculation, and coordinating around a business that can't just close for the day — that's what we do the visit around. If you're a property manager or building owner, we can also set up standing service for the rest of the building's plumbing rather than calling around every time something comes up.
What to do now
Call or contact us with the building type, number of fixtures, and what's failing — cold water at peak hours, an inspector's note, or a remodel that's adding load. We'll schedule a site visit to run the load calculation and quote the right system, not just a bigger box of the same kind.
Related reading: water heater repair & installation, tankless water heaters, commercial plumbing service & repair, tenant improvement plumbing, hot water recirculation, and our FAQ.
We serve commercial properties across Portland, Beaverton, Hillsboro, Gresham, Tigard, Tualatin, Lake Oswego, West Linn, Oregon City, Milwaukie, Happy Valley, Clackamas, Wilsonville, Troutdale, Sherwood, and Salem.