On-demand Unit
On-demand Unit | Tankless Water Heater Install | Plumbing | Greeneville
Imagine stepping into a shower that never runs cold, even during Greeneville’s chilliest mornings—that’s the everyday luxury HEP’s on-demand unit plumbing team delivers. Our seasoned technicians handle every detail of your tankless water heater install, from sizing and venting to flawless final testing, so you can enjoy endless hot water, lower utility bills, and extra storage space the very same day.
Backed by industry-leading warranties, upfront pricing, and 24/7 emergency support, we make upgrading simple and stress-free. Count on local expertise, courteous service, and workmanship that keeps your new system humming for years to come. Ready to trade bulky tanks for pure efficiency? Let HEP turn the tap on comfort today.
FAQs
What is a tankless (on-demand) water heater and how does it work?
Unlike a storage-tank heater that keeps 40–50 gallons of water hot around the clock, a tankless unit heats water only when you open a tap. Cold water flows through a heat exchanger—either gas-fired or electric—and leaves the unit at the set temperature within seconds. Because there is no standby tank, you never "run out" of hot water and waste far less energy keeping water hot when you’re not using it.
Will a tankless water heater really save me money on utilities in Greeneville?
Yes. According to the U.S. Department of Energy, gas tankless heaters can be 24–34 % more efficient for homes that use up to 41 gallons of hot water daily, and 8–14 % more efficient for heavier use. In Greeneville, where natural gas and electricity rates are moderate, most homeowners see 10–25 % lower annual water-heating costs. Savings are even higher if your current tank unit is 10 years old or more.
What size tankless unit do I need for my household?
Sizing is based on flow rate (gallons per minute, GPM) and the temperature rise required. We add up the GPM of fixtures you are likely to run at the same time—e.g., shower (2 GPM) + dishwasher (1.5 GPM) = 3.5 GPM—and factor in that Greeneville’s incoming water temperature averages 55 °F. For a 60 °F rise to reach 115 °F, a typical family of four usually needs a 7.5–9 GPM gas unit or an 18–27 kW electric model. We perform a free on-site evaluation to confirm the exact size.
How long does installation take and will my water be shut off?
Most residential installations in Greeneville are completed in one day. We shut off water and, if applicable, gas or power only during the final tie-in—usually 2–4 hours. If venting or gas-line upgrades are extensive, the job may extend to a second day, but we will always restore service before we leave for the evening.
Will I need to upgrade my gas line, electrical panel, or venting?
Possibly. High-output gas units often require a ¾-inch gas supply line and Category III or IV stainless-steel venting. Electric units larger than 18 kW need 240-V service and up to 150 A of dedicated breakers. During our site visit we measure line sizes, check panel capacity, and inspect vent paths. We provide a written quote that includes any necessary upgrades so there are no surprises.
What maintenance is required and what is the expected lifespan?
With proper care, tankless heaters last 18–20 years—almost double a storage tank. Annual maintenance involves flushing the heat exchanger with a mild descaling solution to remove mineral buildup (Greeneville’s water is moderately hard), cleaning the inlet filter, and checking burner or heating elements. We offer affordable maintenance plans and can set a reminder schedule so you never miss a service.