Tankless Water Heater
Tankless Water Heater | Tankless Water Heater Install | Plumbing | Knoxville
Imagine never running out of hot water during a chilly Knoxville winter shower or family laundry marathon. HEP’s licensed plumbers specialize in tankless water heater install services that swap out bulky, inefficient tanks for sleek, on-demand systems designed to cut energy waste and free up valuable space. With precise sizing, expert venting, and rock-solid warranties, we handle everything—from hauling away your old heater to the final temperature test—so you can enjoy endless hot water the very same day.
Locally owned and rooted in East Tennessee values, HEP backs every installation with transparent pricing, 24/7 emergency support, and a satisfaction guarantee that’s as dependable as the units we mount on your wall. Whether you’re upgrading for energy savings or building your dream home, our team is ready to deliver powerful performance, quieter operation, and monthly utility bills you’ll actually want to open.
FAQs
What are the main advantages of installing a tankless water heater in Knoxville compared with a traditional tank unit?
Tankless (on-demand) heaters heat water only when you open a hot-water tap, eliminating standby heat loss from a storage tank. This typically provides 20–40 % lower energy use, endless hot water for long showers, and a unit that takes far less wall space. In Knoxville’s relatively moderate climate, incoming-water temperatures are not as cold as in northern states, so tankless models reach the set temperature more quickly and achieve higher efficiencies (up to 96 % for condensing gas units). They also last 18–20 years—nearly double the life of a standard tank—reducing long-term replacement costs.
How long does a typical tankless water heater installation take?
For most single-family homes in the greater Knoxville area, a straightforward replacement of a gas tank water heater with a gas tankless unit takes 4–8 hours. The job involves removing the old tank, hanging the new wall-mounted unit, running properly-sized gas or propane lines, installing Category III/IV venting or concentric PVC venting, and connecting water lines with isolation valves and a pressure relief valve. If electrical work or a condensate drain needs to be added, plan for an extra hour. Electric tankless conversions usually run 6–10 hours because new 240-V breakers, heavier gauge wiring, and possibly a panel upgrade are required.
Will I need to upgrade my home’s gas, propane, or electrical service?
Possibly. Gas and propane tankless models require ¾-inch gas piping and supply pressure of 4–10 " wc for natural gas or 8–14 " wc for LP. Many older homes in Knoxville were piped with ½-inch gas lines for a 40- or 50-gallon tank; your installer will perform a gas-load calculation to see if upsizing is needed. Electric tankless units draw 80–150 amps at 240 V; most homes would need at least a 200-amp main panel and three to four dedicated 40–50 amp breakers. A site visit and load assessment are included in our free estimate so you know upfront whether service upgrades are necessary.
What size (flow rate) tankless water heater do I need for my household?
Sizing is based on peak simultaneous demand and incoming water temperature. In Knoxville, winter inlet water averages 50–55 °F, so each fixture needs around 70 °F of temperature rise to reach 120–125 °F. Add up peak flow rates: e.g., shower (2.0 gpm) + dishwasher (1.5 gpm) = 3.5 gpm. You would choose a unit that can deliver at least 4 gpm at a 70 °F rise; that’s roughly a 140–160 k BTU gas model or a 27 kW electric model. For a family of four that might run two showers and a washing machine together (6–7 gpm total), we recommend a 199 k BTU condensing gas tankless. Our technicians perform this calculation during the consultation so you receive the right-sized unit, not an oversold one.
Are there rebates, tax credits, or utility incentives available in Knoxville or Tennessee for tankless water heaters?
Yes. Through 2032, qualifying ENERGY STAR® gas or electric heat-pump water heaters can earn a 30 % federal tax credit (Section 25C) capped at $600 for gas tankless units. Knoxville Utilities Board (KUB) periodically offers $50–$250 bill credits for high-efficiency natural gas appliances. TVA’s EnergyRight program provides 2.0–3.0 ¢/kWh rebates for electric units installed by registered contractors. Rebates change annually, so we verify current offers and prepare all the paperwork, including AHRI certificates and IRS Form 5695, to ensure you get every available dollar back.
What maintenance does a tankless water heater require and what does it cost?
Unlike tanks, tankless heat exchangers can scale up if minerals aren’t flushed. In Knoxville’s moderately hard water (5–7 grains per gallon), we recommend a professional descaling and filter cleaning once per year. The service takes about an hour: we isolate the unit, circulate a food-grade vinegar solution, inspect the combustion chamber or heating elements, and test venting and safety controls. Annual maintenance costs $120–$150 and preserves your manufacturer warranty, which is typically 12–15 years on the heat exchanger. Installing a whole-house sediment prefilter—about $150 installed—reduces scale buildup and extends service intervals.