High-efficiency Units
High-efficiency Units | Tankless Water Heater Install | Plumbing | Knoxville
Enjoy endless hot water, lower utility bills, and extra space in your utility closet when you choose HEP’s high-efficiency units for your tankless water heater install in Knoxville. Our master plumbers remove bulky, outdated tanks and replace them with sleek, on-demand systems that heat water only when you need it—delivering superior performance while cutting energy use by up to 40%. Imagine stepping into a steamy shower seconds after turning the knob, confident that the warmth won’t fade no matter how many loads of laundry are running.
From the first consultation to the final safety check, HEP handles every detail with upfront pricing, tidy workmanship, and a satisfaction guarantee. We’ll size the right unit for your household, secure permits, and leave your home cleaner than we found it—all so you can start enjoying reliable hot water the same day. Ready to make the smart switch? Call or book online and let Knoxville’s most trusted plumbing team elevate your comfort and efficiency.
FAQs
How does a tankless water heater work and why is it considered “high-efficiency”?
A tankless (on-demand) water heater heats water only when you open a hot-water tap. A powerful gas burner or electric element senses the flow and instantly heats water as it passes through a heat exchanger, eliminating the standby heat loss common to storage tanks. Because there is no reservoir to keep hot 24/7, ENERGY STAR®-qualified models can reach efficiency ratings of 95 % or higher, cutting utility bills by 20-40 % compared with a standard tank heater. You also gain an endless supply of hot water, a unit that takes far less wall space, and a product that typically lasts twice as long as a traditional tank.
What size tankless water heater do I need for my Knoxville home?
Sizing is based on simultaneous hot-water demand (in gallons per minute, or GPM) and the temperature rise needed. In Knoxville, incoming water averages about 58 °F. If you want 120 °F at the tap, you need a 62 °F temperature rise. Add up the fixtures you may run at once—e.g., shower (2.0 GPM) + dishwasher (1.5 GPM) + sink (1.0 GPM) ≈ 4.5 GPM. A 180,000 BTU gas unit or a 27 kW electric unit typically delivers 5-6 GPM at that temperature rise, which covers most 2-to-3-bath homes. Larger households or luxury master baths may require a higher-capacity unit or two units in parallel. Our technicians perform a free on-site load calculation to ensure the model we install matches your peak demand without oversizing.
Will a tankless unit work with my existing plumbing, gas, or electric service?
In most cases, yes—both retrofit and new-construction installations are common. 1) Plumbing: We tie the unit into your hot- and cold-water lines at the location of the old tank or an agreed-upon wall; no piping reroute is usually needed. 2) Gas: High-efficiency gas models need a ¾-inch gas line and up to 199,000 BTU/h flow. Homes with older ½-inch lines may require an upsized branch; we verify gas pressure and make any required upgrades. 3) Venting: Condensing units use inexpensive Schedule 40 PVC vented through an outside wall or roof; non-condensing models use stainless-steel venting. 4) Electric: Whole-house electric units need 120-240 amp service and multiple double-pole breakers. We inspect your panel capacity and can install sub-panels or service upgrades if needed. All work meets the latest Knoxville/Knox County building codes and is permitted and inspected.
How long does installation take and what should I expect on install day?
Most residential replacements are completed in one day. Our process: • 8-9 a.m. arrival, water and gas/electric turned off, and old tank drained/removed. • Wall prep and bracket mounting; new vent or condensate drain line installed if required. • Gas/electric, water, and control wiring connections made; we pressure and leak-test all joints. • First system start-up, temperature calibration, and combustion analysis for gas models. • Customer walkthrough on using the controller, maintenance schedule, and warranty registration. We protect floors with drop cloths, haul away the old tank for recycling, and pull any permits needed. For homes that require a gas-line or electrical-service upgrade, allow an extra half-day.
Are there rebates, tax credits, or utility incentives for high-efficiency tankless heaters in Knoxville?
Yes. As of 2024: • Federal IRA Tax Credit: 30 % of total installed cost, up to $600 for non-condensing or $2,000 for ENERGY STAR® condensing gas units that are ≥ .95 UEF. • Tennessee Valley Authority (TVA) EnergyRight: $300 rebate for qualifying gas tankless units installed by a TVA-approved contractor (we are approved). • Knoxville Utility Board (KUB): 0 % financing for up to 12 months on energy-saving appliance upgrades added to your utility bill. • Manufacturer promotions: Many brands offer seasonal discounts (e.g., extended warranties or $100 instant rebates). We handle all paperwork, provide AHRI certificates, and ensure your model meets the latest UEF and gas EF requirements to maximize your savings.
What maintenance is required and how long will a tankless water heater last?
Tankless heaters need far less upkeep than tanks but do require annual service to maintain efficiency and warranty coverage. Our maintenance plan includes: 1) Descaling/flush of the heat exchanger with food-grade vinegar or citric solution to remove mineral buildup (Knoxville’s water hardness averages 70-90 ppm, so yearly flushing is recommended). 2) Cleaning the water and air intake filters. 3) Inspecting burner, venting, and condensate trap (for condensing models). 4) Firmware update and error-history check on digital control boards. With proper maintenance, gas models last 20+ years; electric units average 15-20 years, roughly double the lifespan of a tank heater. Most manufacturers provide a 12- to 15-year heat-exchanger warranty and 5-year parts coverage, which we extend with our Platinum Protection Plan.