Labor Day weekend has quietly turned into one of the busiest stretches of the year for water heater replacements. Contractors use the long weekend to knock out jobs before fall booking picks up, and homeowners who've been putting off a tank that's been groaning for months finally pull the trigger before winter makes the decision for them.
If you've been eyeing an upgrade to tankless, a combination boiler, or a hybrid system with more recovery capacity, this is the week the math tends to work in your favor. Below is a rundown of tankless, combi, and commercial water heaters from Rinnai, Noritz, and Viessmann that are part of our Labor Day 2026 Sale!
Understanding the Basics: Tankless, Combi, and Hybrid Systems
Not every "tankless" water heater does the same job, and the differences matter more than the marketing suggests.
A standard tankless unit heats water on demand as it passes through a heat exchanger. No tank, no standby heat loss, and a footprint you can hang on a wall. These work well for single-family homes and light commercial applications where hot water demand is steady but not extreme.
A combination boiler (combi boiler) does double duty: it heats water for domestic use and also feeds a home's hydronic heating system, whether that's baseboard, radiant floor, or a hydronic air handler. One unit replaces both a water heater and a separate boiler, which saves mechanical room space and installation labor.
A hybrid water heater system pairs a tankless module with a storage tank, giving you the instant recovery of tankless technology plus a buffer of stored hot water for high-demand moments, like a commercial kitchen during a lunch rush or a multi-family building with staggered shower schedules.
Knowing which category you're shopping in narrows the list fast. Here's how the Labor Day lineup breaks down.
Residential Tankless Water Heaters
For single-family homes, the Rinnai RE Series and Noritz EZTR line cover most replacement scenarios without requiring a mechanical room overhaul.
The Rinnai RE199iN and RE199iP are Rinnai's workhorse indoor units, one running natural gas and the other propane, so the choice usually comes down to what's already piped to the house. They're rated to keep up with multiple fixtures running at once in a mid-to-large home, and they're Wi-Fi ready if the customer wants app control down the line. Rinnai backs both with a 15-year warranty on the heat exchanger, and registering within 90 days tacks on extra labor coverage at no cost.
The Noritz EZTR40-NG and EZTR50NG solve a different problem. They're built to drop into the exact footprint of a 40 or 50-gallon tank, top connections and all, so the existing B-vent stays put. On a job where the customer just wants the old tank gone and doesn't want the mechanical room torn apart, that's the difference between a half-day install and a full one.
Get 10% off select tankless water heaters!
Combination Boilers for Heat and Hot Water
If a home is running a separate boiler and water heater, consolidating into one combi unit is often the single biggest efficiency upgrade available during a mechanical room refresh.
The Noritz NRCB199DV-NG and NRCB180DV-NG cover the same job at two different heating loads. The 199DV steps up for larger homes or colder climates where the heating side needs more headroom, while the 180DV handles smaller square footage or milder regions without paying for capacity that never gets used. Either way, one condensing unit replaces what used to be two appliances taking up floor space.
Get 10% off select combi units!
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Commercial and Hybrid Water Heater Systems
Commercial jobs and multi-unit properties need more than a single residential tankless unit can reliably deliver, and this is where hybrid systems and commercial-rated tankless models earn their keep.
The Rinnai Sensei CX199iN is the go-to for small commercial buildings, laundromats, and multi-family properties that need serious flow from one unit, indoors or out, without racking several tankless heaters together to hit the target.
When a single unit still can't buffer the demand, the Rinnai CHS199100HCXIN and CHS398100HCXVIN pair a tankless module with a 119-gallon tank, the larger of the two running roughly double the output. Think hotels or apartment buildings where every unit's shower runs at once on a Monday morning; a straight tankless setup would need to fire far more units than most mechanical rooms have space for.
The Noritz NC199DVCNG rounds things out with a concentric vent option that simplifies venting runs in tighter commercial mechanical rooms.
Get an extended warranty on select units!
Indirect Storage Water Heaters
Not every hot water need is best solved with tankless. If a property already has a boiler doing the heavy lifting, an indirect water heater lets that boiler produce domestic hot water too, without adding a second combustion appliance.
The Viessmann Vitocell 300-V 42-Gallon and 53-Gallon tap into a boiler that's already sized to spare, so the water gets heated without adding a second combustion appliance to the mechanical room. It's often the quieter, more efficient option when the boiler's already doing the work anyway.
Get 10% off select indirect water heaters!
Expert Tips for Sizing and Installation
A few things worth checking before locking in an order:
- Match GPM to fixture count, not square footage: Two bathrooms running simultaneously need more flow than a single large bathroom used one person at a time. Add up worst-case simultaneous demand rather than sizing off house size alone.
- Check existing venting before assuming a drop-in replacement: Tank-replacement units like the EZTR series are built to reuse B-vent, but condensing units typically need PVC or CPVC venting, which may mean a new vent run.
- Factor in lead time for special order items: Several of these units are built to order rather than warehouse stock, so getting a Labor Day order in early matters more than it would for an in-stock item.
- For commercial and hybrid systems, confirm gas line sizing: A 398,000 BTU unit draws a lot more gas than a typical residential tankless heater, and undersized gas lines are one of the most common commercial installation callbacks.
Frequently Asked Questions
What's the difference between a tankless water heater and a combi boiler?
A tankless water heater only heats domestic hot water. A combi boiler heats domestic hot water and also feeds a home's space heating system, like radiant floors or baseboard heat, from the same unit.
Why would I choose a hybrid system over a straight tankless unit?
Hybrid systems add a storage tank to a tankless module, which helps absorb sudden spikes in demand, like a hotel or apartment building during a morning rush, without requiring multiple tankless units racked together.
Do these tankless water heaters need special venting?
Condensing units generally use PVC or CPVC venting, while non-condensing units and tank-replacement models often reuse existing B-vent. Always confirm venting requirements against the specific unit before ordering.
Are commercial water heaters harder to install than residential ones?
They're not necessarily harder, but they do draw significantly more gas and may need larger gas lines, dedicated venting runs, and in some cases three-phase power depending on the model. Planning ahead on infrastructure avoids installation delays.
Are there other water heater deals besides the ones covered here?
Yes. What's covered above is a cross section of the residential, combi, commercial, and indirect lineups on sale, but there are additional models and brands within each of these lines beyond what's featured here. The full water heater selection is part of our Labor Day 2026 Sale, running from September 1 through September 15, 2026.
Ready to Upgrade Before the Season Turns
The 2026 Labor Day Sale runs from September 1 through September 15, and this water heater lineup is one piece of a much bigger event covering pumps, tools, and plumbing supplies across the site. Once the window closes, pricing goes back to normal, and several of these units are built to order, so waiting until the last few days of the sale cuts into the time needed to get one installed before cold weather hits.
Have questions about sizing, venting, or which unit fits your specific job? Give us a call at 888-682-5956, start a live chat, or reach out at contact@plumbingdeals.com and we'll help you land on the right system before the sale ends.
