The Hot Water Myths We Debunk on Every Job

Some of the most persistent hot water myths are the ones that sound the most reasonable. Yes, a running water heater is probably fine. Bigger tanks probably mean more hot water. Tankless systems probably don’t need much upkeep. Probably. The problem is that “probably” has a way of turning into an unexpected repair or a system that quits years too soon. We’ve seen it play out more times than we can count, and plenty of those calls were for water heater repair in Gilbert, AZ.

Here are the myths we run into most.

Myth #1: “Tankless Systems Are Maintenance-Free”

Tankless units still require regular maintenance, largely because of mineral scale. In hard water areas like the Phoenix region, scale builds up inside the unit over time, reduces flow, and strains the heat exchanger. That is the kind of damage that leads to tankless water heater repair when periodic descaling could have prevented it entirely.

Myth #2: “You Never Need to Drain or Flush Your Water Heater”

Skipping this task is one of the most common ways water heaters age faster than they should. Sediment and mineral buildup settle at the bottom of the tank over time, creating a barrier between the burner and the water. The unit works harder, efficiency drops, and the tank lining takes unnecessary wear. Flushing once a year keeps things running clean and is one of the simplest ways to extend the life of a unit before water heater replacement ever becomes a conversation.

Myth #3: “Turn Your Water Heater Off Before a Trip”

The logic makes sense on the surface: why heat water nobody is using? Full shutdowns are generally only worth it for extended absences of two weeks or more. But for most short trips, the energy savings are minimal, and the repeated stress of heating a completely cold tank from scratch can be harder on the system than simply lowering the thermostat to vacation mode. Most modern units have this setting built in. Use it. 

Myth #4: “One Water Heater Brand Is as Good as Any Other”

Brand differences in water heaters are real and they show up in ways that matter: warranty length, parts availability, energy efficiency ratings, and how well the unit holds up in hard water conditions like those common throughout the Phoenix area. 

Myth #5: “Water Heater Installation Is a Solid DIY Project”

Water heater installation involves gas lines or high-voltage electrical connections, pressure relief valve setup, and local code compliance. A mistake in any of those areas creates safety risks that go beyond a cold shower. Permitted, professional water heater installation also protects your warranty and your home insurance coverage in ways that a DIY job typically does not.

Myth #6: “Tankless Means Instant Hot Water, Every Time”

Tankless water heaters heat water on demand, but you will still wait a few seconds for hot water to reach the faucet. That wait has nothing to do with the heater. It is simply how long it takes water to travel through the pipes from the unit to the fixture. What tankless systems actually eliminate is running out of hot water altogether.

Myth #7: “A Higher Thermostat Setting Means You’ll Never Run Out”

Cranking the thermostat does increase the volume of usable hot water by allowing more mixing with cold at the tap, but it also raises energy costs and scalding risk, particularly for households with young children or elderly residents. The U.S. Department of Energy recommends 120°F for most homes. For households with high simultaneous demand, the better answer is a properly sized unit or tankless water heater replacement, not a thermostat pushed into unsafe territory.

Your Hot Water Questions, Answered

How long should a water heater last?

Tank units typically last 8–12 years. Tankless systems, properly maintained, can reach 20 years or more.

Does lowering the thermostat actually save money?

Yes. The DOE recommends 120° for most households, enough for daily use while reducing standby energy loss.

Why is my hot water pressure lower than cold?

It’s usually due to sediment or scale restricting flow through the outlet or supply lines. Worth addressing before it worsens.

Repair or replace: how do I know?

When repair costs approach 50% of replacement cost, or the unit is near end of life, replacement typically wins.

You Know the Myths. We Know Your Water Heater.

Gold Star Plumbing & Drain has been helping Gilbert-area homeowners for over 25 years. We’re a licensed, insured, family-owned company with an A+ BBB rating and more than 1,400 satisfied customers. Our highly trained technicians offer fair pricing, financing options, and same-day service, backed by warranties and available 24/7.

Call Gold Star Plumbing & Drain today and get the honest assessment your hot water system deserves.