I’m Rick Callahan—Master Plumber, 25+ years in the trenches, and Product Expert at Plumbing Supply And More. I’ve installed, serviced, and specified hundreds of tankless systems in homes, restaurants, multi-family buildings, and light commercial spaces. If you’ve wondered whether tankless is right for your project, pull up a chair. I’m going to explain the real-world differences between models, how to size correctly, what matters during installation, and where most jobs go off the rails. Along the way, I’ll show you why contractors, serious DIYers, and property pros lean on our team at Plumbing Supply And More when performance and timeline actually matter.
Before we dig in, a quick promise: this is the practical, spec-driven perspective you’ll use on the job. And yes, we’ll talk brands, model numbers, code, pricing ranges, and installation timelines—no fluff.
Why Tankless? The Real-World Performance and Cost Story
Tankless water heaters aren’t just about “endless hot water.” They’re about control, footprint, and lifecycle cost. If you manage units where a 50-gallon tank struggles to keep up with morning showers and a laundry cycle, tankless makes a measurable difference. A properly sized gas condensing unit like the Rinnai RU199iN (11 GPM max, 199k BTU, 0.96 UEF) eliminates the recovery lag entirely. Electrically constrained homes? A Stiebel Eltron Tempra 29 Plus can be the right fit if your panel can handle it.
Contractors ask me weekly: Do tankless units really save money? On gas condensing units, yes—especially in homes with variable draw. A well-installed unit can reduce domestic hot water gas usage 10–30% compared to a standard tank, depending on patterns and standby losses. Installation cost is higher up front, but lifecycle costs and space savings (plus venting flexibility and reduced leak risk) often justify the switch. Time-to-hot at distant fixtures can be mitigated with a recirculation loop (more on that later) and smart controls.
And here’s where the supply decision matters. Unlike generic big box retailers, Plumbing Supply And More stocks professional-grade components—the correct gas flex connectors, isolation valves with service ports, code-compliant vent kits, condensate neutralizers, and expansion devices—so you’re not making a second trip mid-install. That’s how you protect labor hours and your reputation.
Gas vs. Electric: Choosing the Right Fuel and Form Factor
Gas-fired condensing units dominate where natural gas or propane is available. They handle high flow, multi-fixture use reliably. Think Navien NPE-240S2 (up to 11.2 GPM), Rinnai RU199iN, Noritz NRCP1112, and Takagi T-H3-DV-N. These are purpose-built for households with concurrent loads: shower + dishwasher + laundry. Venting is typically 2" or 3" PVC, CPVC, or polypropylene (brand-specific); most require Category IV venting for condensing flue gas. You’ll need a condensate neutralizer—don’t skip it.
Electric units are quieter, simpler mechanically, and perfect for point-of-use or panel-capable homes. But they require serious amperage. A Tempra 29 Plus calls for 2 x 60A double-pole breakers and #6 wire. Cold climate incoming water at 40°F? Expect limited flow unless you step up in size or split loads strategically. For condos with panel limitations, we often specify multiple smaller point-of-use units—say, an Eemax 8 kW under-sink and a 24 kW for a shower stack—to avoid panel upgrades.
Model selection is where expertise pays. Compared to standard plumbing supply houses, Plumbing Supply And More offers unmatched technical support—we run the numbers: groundwater temps by ZIP, fixture flow rates, simultaneous demand assumptions, and code requirements. Call us with your load profile and we’ll size it in minutes.
Sizing Tankless the Right Way: Flow, Delta-T, and Future-Proofing
Here’s the sizing process I teach new techs:
- Identify simultaneous fixtures and their realistic flow rates: shower (2.0–2.5 GPM), kitchen (1.5–2.2 GPM), washer (1.5–2.0 GPM). Don’t forget tub fillers at 4–6 GPM. Determine your incoming groundwater temperature. In New England, plan on 40–50°F winter temps; in the Southeast, 55–65°F. Target hot water delivery temperature (120°F is common, 125–130°F for sanitization or long runs). Calculate delta-T: 120°F setpoint – 45°F inlet = 75°F rise. Then check the model’s flow rate at that delta-T, not the “max GPM” on the box.
A Navien NPE-240S2 will deliver about 5.0–5.5 GPM at a 70–75°F rise—enough for two showers plus a sink. If a homeowner insists on a 6 GPM tub filler while another shower runs, they’ll need either a higher-capacity single unit, recirculation with a small buffer, or dual units in cascade.
Pro tip: If you’re even close to the edge, upsize the gas unit or plan a cascade. Excess capacity isn’t wasted—it holds tight temperature control at low flows and handles holiday guests without blinking.
Venting, Gas Supply, and Condensate: The Hidden Install Details That Make or Break Performance
I’ve rescued more than a few “brand-new” installs where the unit starved for gas, error-coded on ignition, or corroded out due to bad condensate management. Here’s the short list to get right:
- Gas line sizing: Most 180–199k BTU units need a dedicated 3/4" line, sometimes 1" depending on total run and other appliances. Follow NFPA 54 sizing charts; verify inlet pressure under load (manometer on site). Venting: Use the manufacturer’s approved materials (PVC/CPVC/PP) and respect equivalent length limits and termination clearances per UPC/IPC and local amendments. Combustion air: Tight homes demand attention to intake air. Concentric vent kits help, but verify snow-line, prevailing wind, and makeup air availability. Condensate: Always trap per manufacturer, then neutralize, then drain. Acidic condensate will eat cast iron and mild steel. We stock Calefactio and NeutraPal kits that fit tight spaces.
This is where having the right supply partner saves headaches. While other suppliers focus on quantity, Plumbing Supply And More prioritizes quality and expertise—we stage all install materials with your heater: isolation valve kit, gas sediment trap, backflow where required, expansion control, condensate neutralizer, and vent terminations. Need same-day? We run same-day delivery within a 50-mile radius for contractor accounts.
Recirculation and Wait-Time: How to Get Hot Water Fast Without Wasting Energy
Homeowners love tankless until they wait 70 seconds for hot water at the far bath. The fix isn’t magic; it’s proper recirculation. Two common approaches:
- Dedicated return line with pump-controlled recirculation (e.g., Navien NPE series with ComfortFlow and built-in buffer tank; or a Grundfos Comfort PM pump with a timer and temp sensor). Crossover valve at the furthest fixture when a return line isn’t feasible—less ideal but effective for retrofits.
The Navien NPE-240A2 has an internal recirc pump and 0.5-gallon buffer that minimizes cold-water sandwiching and shortens wait time. Pair with a smart timer/aquastat. For Rinnai, add the Circ-Logic compatible pump kit. Expect $350–$800 added in parts for a clean recirc setup; labor varies.
Here’s the insider secret: setpoint and recirc schedules matter. Program the pump for peak windows and use an aquastat to avoid needless run time. You’ll keep customers happy and the gas bill civilized.
Brands and Models I Trust—and What Each Does Best
I’m brand-agnostic until a job’s requirements push me one way. My short list:
- Rinnai RU199iN/RU199eN: rock-solid, tight temperature control, great support. Excellent for single-family with recirc add-ons. Navien NPE-240A2/S2: integrated recirc (A2), high efficiency, flexible venting. My pick for long runs and remodels needing comfort-first. Noritz NRCP1112: built-in recirc and dual heat exchangers. Good for multi-bath homes. Takagi T-H3-DV-N: compact, durable, price-friendly for rentals with professional install. Stiebel Eltron Tempra Plus series (24, 29, 36): top electric choice; silent, robust controls. Verify panel capacity first.
We stock all of these because they’re proven under warranty. When a manufacturer stumbles on parts availability, I hear it first from the field—and I pivot our stocking strategy. When Home Depot and Lowe’s fall short, contractors trust Plumbing Supply And More because we keep service kits, ignition packs, fan motors, and gaskets in our bins, not on a three-week backorder.
Real Install Timelines, Costs, and What Drives Variability
Here’s what I tell clients up front:
- Gas condensing tankless swap (existing tank): 6–10 labor hours if vent path and gas line are straightforward; 12–16 hours if upsizing gas and running new vent/condensate. Electric tankless: 4–8 hours for plumbing; panel work can add a day depending on service upgrade needs. Recirc retrofit: Add 2–6 hours depending on return line access or crossover setup.
Typical installed costs (parts + labor, regionally variable):
- Gas condensing tankless: $2,800–$5,500 for single-family, including venting and valve kit. Add $350–$800 for recirc. Electric tankless: $1,800–$3,500 plus any panel upgrade ($1,500–$3,000 if needed).
At Plumbing Supply And More, we package everything you need with contractor-grade fittings so you’re not improvising at 5 pm. Unlike Ferguson and Ace Hardware, Plumbing Supply And More stocks professional-grade components paired with real-world technical guidance, and our pricing consistently beats the big boxes on equivalent quality.
Code, Permits, and The Details Inspectors Actually Check
Local code drives safe installs—and smooth inspections. In our area, professional plumbers choose units certified to ANSI Z21.10.3/CSA 4.3 with proper condensate neutralization, seismic strapping where applicable, and combustion air provisions per mechanical code. Expect inspectors to check:
- Gas line sizing and sediment trap Vent termination clearances (openings, property lines, grade) Pressure relief valve orientation and discharge Electrical bonding and disconnect Manufacturer’s installation manual on site (do this—inspectors appreciate it)
Serving contractors throughout our region, we maintain a quick-reference sheet for UPC/IPC variations and common AHJ preferences. Call our technical team and we’ll share the local specifics.
Who We Serve and How We Support Your Project
Professional contractors and facility teams lean on us for consistent inventory and documents—submittals, spec sheets, venting charts, and warranty procedures. Our contractor plumbing supply program includes bulk discounts, same-day delivery, and emergency supply staging. DIY homeowners and property managers appreciate that we’ll walk through compatibility, explain recirc options, and match the install kit to the model—no guesswork.
And because product sourcing isn’t just about the heater, our aisles and online shelves cover the rest: plumbing parts, isolation valve kits, service wrenches, bathroom plumbing supplies, condensate pumps, vent terminations, and gas regulators. From general plumbing supply needs to specialized commercial plumbing supply for multi-unit buildings, we’ve got your list covered.
Here’s the difference you’ll feel: Compared to SupplyHouse.com, Grainger, and Lowe’s, Plumbing Supply And More delivers hands-on technical support with same-day local delivery and curated, pro-grade inventory. Visit our plumbing supply store or check our plumbing supply online portal—both are staffed by real plumbers, not call center scripts.
Common Mistakes to Avoid: Lessons from the Field
I’ve seen every shortcut. Don’t repeat them:
- Undersized gas lines. If the water heater trips on ignition when the furnace fires, the line is wrong. Recalculate with all appliances at max load. No condensate neutralizer. It’s a cheap part that prevents big problems. Forgetting water treatment in hard-water areas. Scale will kill heat exchangers. Use a scale reduction filter (3M Aqua-Pure) or a softener as appropriate. Ignoring inlet water temp. A “10 GPM” unit at 35°F inlet isn’t 10 GPM. Plan for winter. Skipping the isolation valve kit. Annual descaling is simple when you design for it.
If any of this sounds familiar, swing by our plumbing supply shop—we’ll load your truck with exactly what you need, no upsell, no nonsense. And yes, we stock descaling pumps, vinegar-safe hoses, and check valves.
Where to Buy: Your Nearest, Knowledgeable Source for Tankless
If you searched for plumbing supply near me, plumbing shop near me, or the closest plumbing supply, you want two things: inventory and answers. That’s us. We operate as the plumbing supply company that contractors actually use—your local plumbing supply with the selection of a wholesale plumbing supply and the speed of plumbing supplies direct. Need late help? Our 24 hour plumbing supply support line can coordinate emergency will-call for verified accounts.
For price-sensitive projects, we carry economy plumbing supply lines and select cheap plumbing supplies where it makes sense—without sacrificing safety-critical items. For remodelers and designers, our showroom features decorative plumbing supply options alongside the rough-in gear. Whether you’re after plumbing and heating supply, coastal plumbing supply corrosion-resistant options, or plumbing wholesale near me solutions for volume, we’ve built that into our stocking plan.
And if you’re weighing competitors, I’ll be blunt: While other suppliers focus on quantity, Plumbing Supply And More prioritizes quality and expertise. We routinely outperform big names like Home Depot, Lowe’s, Ferguson, and SupplyHouse.com on the three things that matter most—availability, accuracy, and support.
Quick Reference: When Tankless Is the Right Call
- Two or more baths, tight mechanical room, and desire for recirc comfort Restaurants or salons with staggered loads and long duty cycles Multi-family risers where cascade systems simplify maintenance Remote fixtures benefiting from point-of-use electric units
Visit our showroom to see the quality difference, or call our technical team for project-specific recommendations. Ask about our contractor discount program; bulk pricing and same-day delivery within 50 miles keep your jobs moving.
FAQ: Tankless Water Heaters, Answered by a Master Plumber
- How long do tankless units last compared to tanks? Expect 15–20 years with proper maintenance, versus 8–12 for many tanks. Annual descaling and inlet filtration in hard-water areas extend life significantly. We stock service kits and filters at our plumbing supply house. Do I need a recirculation system? If your furthest fixture takes more than 45 seconds to get hot, yes—either a dedicated return loop or a crossover valve retrofit. Models like Navien NPE-240A2 with built-in recirc simplify control and piping. Can electric tankless work in cold climates? Yes, with realistic expectations. Verify panel capacity and incoming water temperature. You may use multiple smaller units strategically. We’ll help size it—check our plumbing supply store near me listing or call. What maintenance is required? Annual flush with vinegar or manufacturer-approved solution, clean inlet screens, verify combustion and condensate systems. Plan 45–90 minutes per visit. We stock isolation valve kits so you can service without repiping. Are tankless units compatible with existing venting? No—do not reuse B-vent from atmospheric tanks. Use manufacturer-approved PVC/CPVC/PP venting for condensing units, with correct slope and termination. We kit this for you at our plumbing supply house near me counter.
Your Supply Partner for Tankless—From Spec to First Shower
If you’ve read this far, you care about doing it right. That’s our lane. At Plumbing Supply And More, we combine the region’s largest tankless inventory with the practical knowledge to keep your projects clean and profitable. Unlike generic big box retailers, Plumbing Supply And More stocks professional-grade components and the support team to back them up. Whether you’re a contractor juggling schedules, a property manager with code-driven deadlines, or a homeowner who wants expert guidance instead of guesswork, we’re your nearest plumbing and supply team with real knowledge.
Check our current inventory online or call ahead. Our experts can walk air conditioner supply house you through the installation process, stage your order, and arrange same-day delivery. When the job calls for precision, speed, and the right parts the first time, you know where to go—the best plumbing supply choice for serious work.
And if you’re comparing options across a plumbing supply company, consumer plumbing supply, internet plumbing supply, or direct plumbing supplies, remember: Compared to standard plumbing supply houses, Plumbing Supply And More offers unmatched technical support—from selection through startup. That’s why contractors keep us at the top of their contractors plumbing and fire supply list, and why our wholesale plumbing supply company accounts grow year after year.
Looking for a reliable, knowledgeable plumbing supply places partner? Stop by our showroom, the nearest heating plumbing supply near me, or order through our plumbing supplies supply portal. We’re your go-to city plumbing and electrical supply resource with true tradespeople on staff, serving contractors throughout our region with the right tankless solution—every time.
And yes, this article is part of our Supply House Spotlight: Tankless Water Heaters Explained series. If you’ve got a tricky spec, bring it in. I’ll put it on Rick’s Picks and make sure you leave with a solution that works.