Water Heater Maintenance Checklist for Keller TX Homeowners (2026)

By Brent Applegate, Licensed Master Plumber | Polly Plumbing | License No. RMP-42199 Serving Keller, Southlake, Trophy Club, Roanoke, Flower Mound, Colleyville, North Richland Hills, and all of Tarrant and Denton Counties. Based in Keller, TX.

Water Heater Maintenance Checklist for Keller TX Homeowners (2026)

Water heater maintenance in Keller TX is not the same as water heater maintenance anywhere else in the country. Tarrant County hard water runs 15 to 25 grains per gallon — roughly double the national average. That single fact changes every maintenance interval you will read on a national website or find on the sticker inside your water heater door. This checklist gives you the correct schedule for this market, the tasks that matter most, and the honest cost of each one. Follow it and your water heater will last toward the top of its rated lifespan. Ignore it and you will replace it two to four years earlier than you should. Call (817) 286-3446) to schedule any of these services with Polly Plumbing.

A Real Conversation From a Keller Homeowner

David called about a 9-year-old AO Smith gas water heater in his garage. He had never had it serviced. He was not calling because it was broken. He was calling because he had just read an article Polly Plumbing published about anode rods and realized he had no idea what condition his unit was in.

Brent arrived and ran through the full checklist. The tank flush pulled significant sediment — dark rust-colored water that took four drain cycles to run clear. The anode rod was down to roughly 20 percent of its original material. The expansion tank pressure was at 40 PSI when it should have been closer to 80. The T-P valve discharged correctly on test.

Total service time: 90 minutes. Cost: a tank flush plus anode rod replacement. Less than 20 percent of the cost of a new water heater.

David asked how many more years he could expect from the unit with regular maintenance going forward. Brent told him honestly: the tank had been operating without anode rod protection for at least one to two years based on the rod’s condition. There was no way to know exactly how much internal corrosion had occurred during that period. He could expect the unit to last two to four more years with proper maintenance from here, or it could fail sooner if the tank had already corroded significantly.

That is the honest answer. Maintenance extends life. It does not guarantee it. The best time to start maintaining a water heater is during installation. The second best time is right now.

Why Maintenance Intervals Are Different in Keller and Tarrant County

Before the checklist, here is the context that makes every item on it make sense.

Water hardness is double the national average. Tarrant County water hardness of 15 to 25 GPG deposits calcium and magnesium on every internal surface of your water heater at roughly double the national rate. The national maintenance recommendations on the side of your water heater and on most websites are calibrated for 7 to 10 GPG water. They do not apply here without adjustment.

Most Keller water heaters are in unconditioned garages. Garages in Keller cycle from 115 degrees in August to near-freezing in January cold snaps. That thermal cycling accelerates seal deterioration, stresses the tank body, and creates condensation on cold incoming water lines that can be mistaken for a leak.

Anode rod depletion is accelerated. In Tarrant County hard water, the protective anode rod inside your tank depletes in 3 to 5 years instead of the national average of 5 to 7 years. Once depleted, the tank steel corrodes directly. This is the single most important maintenance item in this market and the one most commonly skipped because it requires removing a component most homeowners do not know exists. For a full explanation of what the anode rod does and why it matters here specifically, see our water heater anode rod guide for Keller TX.

Hard water produces more sediment faster. Sediment accumulates on the tank floor as calcium deposits settle out of the hot water. In this market, annual flushing is the right interval. Nationally, biennial flushing is sometimes recommended. That advice does not apply in Tarrant County.

The Complete Water Heater Maintenance Checklist for Keller TX

Task 1: Annual Tank Flush

Frequency: Once per year, every year Cost: $390 to $650 DIY or professional: Professional recommended for units over 5 years old in Tarrant County water

A tank flush removes the sediment that has accumulated on the tank floor over the past 12 months. Sediment insulates the heating element or burner from the water above it. The unit works harder, uses more energy, produces less hot water, and wears out faster.

In Tarrant County hard water, sediment builds significantly faster than in lower-hardness markets. A unit that goes more than two years without a flush in this market will show a noticeable reduction in hot water output and efficiency.

The flush also clears debris from the drain valve and gives the plumber a visual confirmation that the water running out of the tank is clean and clear rather than rust-colored or heavily sediment-laden. Rust-colored flush water on a unit that is 9 or more years old without a softener is a signal to begin planning replacement.

Why professional is recommended for older units: The drain valve on units over 5 years old in Tarrant County water is often heavily corroded and can seize or leak after flushing. A professional arrives with a replacement valve on the truck if needed. Attempting to flush a corroded drain valve yourself risks turning a maintenance task into an emergency.

Task 2: Anode Rod Inspection and Replacement

Frequency: Inspect at year 3, replace if over 50 percent depleted. Without a softener: expect replacement at year 3 to 5. With a softener: inspect at year 5, expect replacement at year 5 to 7. Cost: Bundled into the annual service visit DIY or professional: Professional strongly recommended

The anode rod is the most important maintenance item on a tank water heater in Tarrant County and the most commonly neglected. It is a sacrificial metal rod screwed into the top of the tank. It corrodes instead of the steel tank wall. When it is fully depleted, the tank starts corroding directly.

In Tarrant County hard water, the anode rod depletes in 3 to 5 years. The national recommendation of every 5 years does not apply here without a water softener. A homeowner who follows the national interval will go one to two years without anode protection in this market before the rod is replaced.

Brent checks the anode rod on every water heater service call and includes the finding in the written visit summary. If it is more than half depleted, he replaces it that visit. If it still has meaningful material remaining, he documents it and sets the next inspection date.

Task 3: T-P Valve Test

Frequency: Once per year Cost: Included in annual service visit. Replacement if needed: $470 to $790 DIY or professional: Professional recommended

The temperature and pressure relief valve is a safety device. If the water heater overheats or pressure builds to unsafe levels, the T-P valve opens and releases water to prevent a catastrophic failure. A T-P valve that has never been tested may be corroded in the closed position and fail to open when needed.

Testing it annually confirms it opens and reseats correctly. A valve that weeps continuously after testing has a degraded seat and needs replacement. Do not ignore a weeping T-P valve. It can indicate high system pressure, thermal expansion, or a failed valve — all of which need diagnosis.

If your home does not have a thermal expansion tank and you are on a closed plumbing system, the T-P valve may be discharging regularly because thermal expansion has nowhere to go. Replacing the valve alone will not solve this. The expansion tank is the correct fix. For a full explanation, see our article on thermal expansion tanks for Keller TX homes.

Task 4: Expansion Tank Pressure Check

Frequency: Once per year Cost: Included in annual service visit. Replacement if needed: $340 to $570 DIY or professional: Professional

The thermal expansion tank absorbs the pressure increase when water heats and expands in a closed plumbing system. It has an internal bladder and a pre-charge pressure that should match your home’s water pressure. Over time the bladder can fail or the pre-charge pressure can drop.

An expansion tank that is waterlogged — meaning the bladder has failed — provides no protection. The T-P valve on the water heater becomes the only pressure relief, opening regularly and wearing out prematurely.

Brent checks expansion tank pressure with a simple air pressure gauge on every service visit. A correctly functioning expansion tank takes 30 seconds to confirm. A failed one takes 30 minutes to replace.

Keller, Southlake, Trophy Club, and surrounding cities require a thermal expansion tank on all new water heater installations. Many older homes in the area had units replaced before this requirement was in place and do not have one. If your water heater was installed before 2015 and has never had an expansion tank added, ask Brent to check whether your system needs one.

Task 5: Inspect Inlet and Outlet Connections

Frequency: Once per year, visual check Cost: Included in annual service visit. Repair if needed: $240 to $610 depending on component DIY or professional: Professional

The cold water inlet and hot water outlet connections at the top of the tank are joined to the supply pipes with dielectric nipples or flex connectors. In Tarrant County hard water, these connections corrode at the threads over time. The most common failure is a slow drip at the top of the unit that homeowners mistake for condensation.

A visual inspection during the annual service visit identifies any corrosion, staining, or moisture at these connections before they become a leak. Dielectric nipple replacement is a straightforward repair on units that are otherwise in good condition.

Task 6: Check the Pilot Light and Burner Assembly (Gas Units)

Frequency: Once per year Cost: Included in annual service visit DIY or professional: Professional

On gas water heaters, the burner assembly and pilot light area accumulate dust and debris over time, particularly in garage installations where dust and insulation fibers are present. A dirty burner produces an uneven flame that reduces heating efficiency and can accelerate wear on the thermocouple.

A professional inspection includes a visual check of the burner flame color and pattern. A clean, blue flame is correct. An orange or yellow flame indicates incomplete combustion and a burner that needs cleaning or adjustment.

Task 7: Confirm the Anode Rod Port Is Accessible

Frequency: At every service visit Cost: Included DIY or professional: Professional

This is a simple but important check. The anode rod port must be accessible to perform the replacement when due. In some installations, the water heater is positioned against a wall or in a tight alcove that makes the port difficult to reach. Brent documents the access situation on every service visit so that if the anode rod needs replacement, there are no surprises about access when that time comes.

The Annual Service Visit: What Polly Plumbing Covers in One Call

All seven tasks above are covered in a single annual water heater service visit from Polly Plumbing. You do not need separate visits for each item.

A standard annual maintenance visit covers the tank flush, anode rod inspection and replacement if needed, T-P valve test, expansion tank pressure check, connection inspection, and burner check on gas units. Brent documents every finding in a written visit summary that you keep. The summary notes the anode rod condition and replacement date, the flush results, the T-P valve test result, and the expansion tank pressure reading.

That documentation matters. When you eventually need to decide whether to repair or replace the unit, you have a written maintenance history that tells you exactly what condition the tank has been in and how well it has been maintained. A well-maintained unit with documented service history has a different repair-versus-replace conversation than an unmaintained unit of the same age.

For service areas covered by Polly Plumbing for annual water heater maintenance: Keller, Southlake, Trophy Club, Roanoke, Flower Mound, Colleyville, North Richland Hills, and all of Tarrant County and Denton County.

Call (817) 286-3446) to schedule your annual water heater maintenance visit.

Tankless Water Heater Maintenance in Keller TX

Tankless water heaters do not use an anode rod and do not accumulate sediment in a tank. But they are not maintenance-free in Tarrant County hard water. They have a different set of maintenance requirements.

Annual Descaling

The heat exchanger in a tankless unit is a dense series of small-diameter water passages that heat water on demand. In Tarrant County hard water, calcium deposits build up inside these passages over time. The deposits narrow the flow paths, reduce heat transfer efficiency, and eventually cause the unit to overheat and shut down.

Annual descaling with a food-grade descaling solution flushes the calcium deposits from the heat exchanger and restores full efficiency. In Tarrant County without a water softener, annual descaling is the correct interval. With a softener, every two years.

A tankless unit in Tarrant County hard water without a softener that has never been descaled for five or more years is likely operating at significantly reduced efficiency and may be approaching a heat exchanger failure.

Cost: $370 to $620 for a professional descaling service.

Inlet Filter Screen Cleaning

Tankless units have a small filter screen on the cold water inlet that catches debris before it enters the heat exchanger. In Tarrant County, fine sediment particles in the water can partially clog this screen over time, reducing water flow and causing the unit to activate and deactivate rapidly. Cleaning the inlet filter is a simple task that takes 10 minutes but is worth checking annually.

Venting Inspection

Gas tankless units are direct-vent or power-vent systems with PVC or stainless flue pipes. Annual inspection of the vent termination point confirms no debris, bird nests, or pest intrusion has blocked the exhaust. A blocked vent causes the unit to fail safe and shut down.

For a full comparison of tankless versus tank water heater maintenance requirements in this market, see our tankless vs tank water heater guide for Keller TX.

Maintenance Cost Summary for Keller TX

All pricing includes parts and labor. Written quote before work begins on any repair or replacement item found during the service visit.

What Happens If You Skip Maintenance in Keller TX

Here is the honest picture of what skipping annual maintenance costs a Keller homeowner over the life of the unit.

Year 1 to 3, no maintenance: Sediment begins building on the tank floor. Efficiency drops gradually. You will not notice it yet. The anode rod is depleting.

Year 3 to 5, no maintenance: The anode rod has likely depleted fully in Tarrant County water. The tank steel begins corroding without protection. Sediment is now a meaningful layer on the tank floor. Hot water recovery slows. Energy use increases.

Year 6 to 8, no maintenance: Internal tank corrosion is active. Sediment layer is significant. The unit runs longer heating cycles to produce the same hot water it used to produce faster. The expansion tank bladder, if one exists, may have failed silently. The T-P valve has never been tested and its condition is unknown.

Year 9 to 10, no maintenance: The unit is in the failure window for Tarrant County hard water without a softener. Bottom seam corrosion or tank body failure becomes the expected outcome rather than the exception. A unit that has been maintained from the start can expect two to four more years of life at this point. An unmaintained unit is on borrowed time.

For the complete picture of what affects water heater lifespan in Tarrant County and how to know where your unit stands right now, see our water heater lifespan guide for North Texas homeowners.

When the unit does fail, the cost is the replacement — $2,510 to $4,180 for a standard 50-gallon gas unit all-in — plus the inconvenience of an unplanned same-day service call. See our water heater replacement cost guide for Keller TX for the full breakdown of what that cost includes.

For a full comparison of tankless versus tank water heater maintenance requirements in this market, see our tankless vs tank water heater guide for Keller TX.

When Maintenance Is Not Enough: Signs Your Water Heater Needs Replacement

Annual maintenance extends life. It does not repair a tank that has already failed internally. These signs mean the unit needs replacement regardless of its maintenance history.

Rust-colored or metallic-tasting hot water means the tank is corroding into the water supply. No repair fixes this. A leak from the tank body or bottom seam means the steel wall has failed. This requires same-day replacement. A unit that is 10 or more years old in Tarrant County water without a softener and showing multiple symptoms is at the end of its realistic service life.

For a full diagnosis of when repair makes sense and when it does not, see our water heater leaking guide for Keller TX and our no hot water diagnostic guide for Keller TX.

Frequently Asked Questions About Water Heater Maintenance in Keller TX

How often should I flush my water heater in Keller TX?

In Keller and Tarrant County hard water without a water softener, flush your water heater once per year. The national recommendation of every two years is calibrated for average water hardness of 7 to 10 GPG. Tarrant County water runs 15 to 25 GPG, roughly double the national average, which means sediment accumulates significantly faster. Annual flushing costs $390 to $650 and is one of the most cost-effective maintenance tasks for extending tank life in this market. Call Polly Plumbing at (817) 286-3446 to schedule.

How often should the anode rod be replaced in Keller TX?

In Tarrant County hard water without a water softener, inspect the anode rod at year 3 and replace if more than 50 percent depleted. Expect replacement between years 3 and 5. With a water softener, inspect at year 5 and expect full replacement interval of 5 to 7 years. The nationally recommended interval of every 5 years does not account for Tarrant County water hardness and will leave your tank without anode protection for one to two years in this market.

What does water heater maintenance cost in Keller TX?

An annual water heater service visit covering the tank flush, anode rod inspection, T-P valve test, expansion tank check, and connection inspection runs $390 to $650 for the flush component plus any parts if replacement items are needed. A T-P valve replacement runs $470 to $790. An expansion tank replacement runs $340 to $570. All pricing includes parts and labor with a written quote before any work starts. Polly Plumbing does not charge an emergency surcharge. Call (817) 286-3446.

What happens if I never maintain my water heater in Keller TX?

In Tarrant County hard water without a softener, an unmaintained tank water heater typically fails 2 to 4 years earlier than a maintained unit. The anode rod depletes unnoticed, tank corrosion begins, sediment accumulates to the point of significant efficiency loss, and the unit fails at a time you have not planned for. The cost of proactive annual maintenance is a fraction of the cost of an unplanned same-day replacement. The failure also frequently occurs during storms or cold snaps when demand on the unit is highest.

Do I need to maintain a tankless water heater in Keller TX?

Yes. Tankless units do not accumulate sediment in a tank but they have a heat exchanger that is highly susceptible to calcium scale buildup in Tarrant County hard water. Annual descaling is required without a water softener to prevent heat exchanger restriction and eventual failure. Annual descaling costs $370 to $620. A tankless unit that has never been descaled in Tarrant County water for 5 or more years is likely operating at reduced efficiency and may be approaching a heat exchanger failure.

How do I know if my water heater needs maintenance?

If your unit is more than 12 months past its last tank flush, it is due. If you do not know when the anode rod was last replaced and the unit is more than 3 years old without a softener, it needs an inspection. If your hot water takes longer to recover than it used to, sediment accumulation is the likely cause. If the T-P valve drips occasionally, the system may have a thermal expansion problem. Any of these are reasons to call Polly Plumbing at (817) 286-3446 for an assessment.

Does a water softener reduce how often I need to maintain my water heater in Keller TX?

Yes, significantly. A whole-home water softener removes calcium and magnesium from incoming water before it enters the tank. This slows sediment accumulation, extends anode rod life from 3 to 5 years toward 5 to 7 years, and reduces scale buildup in tankless heat exchangers from annual to every two years. A water softener is the single most impactful step a Keller or Tarrant County homeowner can take to extend water heater life and reduce the total cost of ownership over the unit’s lifespan.

Written by Brent Applegate, Licensed Master Plumber, Polly Plumbing. Texas License RMP-42199. Based in Keller, TX. Serving Tarrant and Denton Counties.

Published: May 2026. Last reviewed: May 2026.