Tankless water heating has moved from a niche upgrade to a mainstream choice, and the Essency water heater lineup is one of the value-focused brands homeowners encounter when shopping for on-demand hot water. If you are weighing an Essency water heater against a traditional tank or a bigger-name tankless brand, the questions that matter are the same across all of them: correct sizing by flow rate, proper gas or electric supply, venting, and ongoing maintenance. This guide explains how to evaluate the unit, size it to your household, and keep it running efficiently for the long haul.
Tank Versus Tankless Basics
A traditional water heater stores 40 to 80 gallons of hot water and keeps it hot around the clock, losing energy as standby heat loss even when no one uses it. A tankless unit heats water only as it flows through, firing a burner or element the instant you open a hot tap and shutting off when you close it.
The payoff is endless hot water, since there is no tank to drain, plus lower standby energy loss and a compact wall-mounted footprint that frees up floor space. The trade-offs are a higher upfront cost, the need for adequate gas supply or electrical capacity, and a flow-rate ceiling that means you must size the unit to your simultaneous demand rather than a fixed tank volume.
Sizing by Flow Rate, Not Gallons
The single most important concept with any tankless unit, including an Essency, is that you size it by gallons per minute of flow, not by tank capacity. You add up the fixtures you might run at once and match the unit’s rated GPM to that peak demand at your required temperature rise.
- Bathroom faucet: about 1.0 GPM
- Kitchen faucet: about 1.5 GPM
- Shower: about 1.5 to 2.5 GPM
- Dishwasher: about 1.0 GPM
- Washing machine: about 2.0 GPM
If you want to run two showers at once in a cold climate, you may need 5 GPM at a 60 to 70-degree temperature rise, which pushes you toward a larger unit or even two in parallel. Undersize the heater and the water turns lukewarm when demand spikes.
Understanding Temperature Rise
Temperature rise is the gap between your incoming groundwater temperature and your target output, and it dictates how much flow a given unit can actually deliver. A tankless heater rated for high GPM in Florida delivers far less in Minnesota, because northern groundwater arrives much colder.
Incoming water might be 70 degrees Fahrenheit in the South and 40 degrees in the North. To reach a 120-degree tap, a southern home needs only a 50-degree rise while a northern home needs 80 degrees. The same unit that pumps out 6 GPM at a 45-degree rise may only manage 3.5 GPM at an 80-degree rise. Always check the manufacturer’s flow chart for your climate, not the headline maximum GPM number.
Gas Versus Electric Models
Tankless heaters come in gas-fired and electric versions, and the right choice depends on your home’s utilities. Gas models produce far more heating power, easily handling whole-home demand, but they require a properly sized gas line, often 3/4 inch, and dedicated venting.
Electric tankless units are simpler to install with no venting, but whole-home electric models draw enormous current, sometimes 100 to 150 amps across multiple double-pole breakers, which many older panels cannot supply. Electric units make the most sense for point-of-use applications or smaller homes with adequate electrical service. Confirm your gas line size or your panel capacity before committing to either type.
Installation and Venting
A gas tankless install is more involved than swapping a tank and is usually a job for a licensed plumber. Key requirements include:
- An adequately sized gas supply line to feed the burner’s high BTU demand at full fire.
- Stainless steel Category III or concentric venting for standard units, or PVC venting for condensing models that run cooler exhaust.
- A 120-volt outlet nearby to power the electronics, ignition, and fan.
- Isolation valves on the hot and cold lines to allow future descaling.
- Proper condensate drainage for condensing models, which produce acidic condensate that may need neutralizing.
Professional installation of a gas tankless typically runs $1,000 to $3,000 on top of the unit, more if you need to upsize the gas line or run new venting. Budget for the isolation valve kit; it makes annual maintenance far easier.
Maintenance and Descaling
Tankless heaters are sensitive to hard water because mineral scale builds up on the heat exchanger and chokes flow and efficiency. In hard-water regions, plan to descale the unit once a year, or more often above 12 grains per gallon of hardness.
Descaling is straightforward if the plumber installed isolation valves: you connect a small pump and hoses, circulate a food-grade descaling solution or white vinegar through the heat exchanger for 45 minutes to an hour, then flush with clean water. Also clean the inlet water filter screen a couple of times a year to keep debris from restricting flow. A water softener upstream dramatically reduces scaling and extends the life of any tankless unit.
Common Tankless Problems and Fixes
Tankless units are reliable but have a few characteristic quirks worth knowing. The most talked-about is the cold water sandwich, a brief slug of cold water that arrives mid-shower when someone shuts off and quickly reopens a tap. It happens because the burner takes a second or two to refire, and it is normal rather than a defect. A small buffer tank or a recirculation feature reduces it.
Another common complaint is a minimum flow threshold. Tankless heaters need a certain flow, often around 0.5 GPM, to fire the burner, so a trickle from a barely opened faucet may run cold. Error codes are your friend here, since these units display diagnostic codes on a small screen or blink a fault light. A scale buildup code means it is time to descale, an ignition code often points to gas supply or venting, and a flow-sensor code may mean a clogged inlet filter. Keep the manual handy so you can decode these rather than immediately calling for service.
Warranty and Longevity
One of the strongest arguments for tankless is lifespan. A traditional tank heater typically lasts 8 to 12 years before the tank corrodes and leaks, at which point the whole unit is scrap. A well-maintained tankless heater often runs 15 to 20 years because there is no tank to rust out, and its heat exchanger and internal parts are serviceable and replaceable.
Manufacturers back this longevity with warranties that usually cover the heat exchanger for 10 to 15 years and other parts for shorter terms. The catch is that many warranties require proof of proper maintenance, particularly annual descaling in hard-water areas, so keep records of your flushes. Register the unit at purchase and follow the maintenance schedule, because a heat-exchanger claim denied over a skipped descaling turns a covered repair into a costly one. Factor the longer service life into the value equation, since spreading the higher upfront cost over 18 years of service changes the math considerably in tankless’s favor.
Is It the Right Choice for You
A tankless water heater like an Essency makes the most sense if you want endless hot water, value the space savings, and plan to stay in the home long enough to recoup the higher upfront cost through energy savings. It shines in homes with moderate, spread-out demand and adequate gas or electrical service.
If your household routinely runs many fixtures at once in a cold climate, size generously or consider two units, and factor in the descaling maintenance if you have hard water. Compare the specific model’s GPM at your local temperature rise, confirm your utilities can support it, and budget realistically for professional installation. Sized and maintained correctly, a tankless unit delivers reliable on-demand hot water and lower operating costs for well over a decade.
