February 18, 2025
Preventive Maintenance Can Extend Your Water Heater’s Useful Life… Check Yours Today!

Your water heater is probably the most important part of your homes plumbing system. A properly maintained heater can last from ten to fifteen years or more. But, a heater not properly maintained can fail in four to six years. The condition of the drinking water in your area and the location of the heater in your home are out of your control, but proper maintenance of the heater and your plumbing system is crucial to heater longevity and safety.

This article gives you a list of items to check for both tank type and tankless water heaters. As you go through the steps in checking your heater, if you have the slightest doubt in your ability, get a professional, licensed plumber involved! You are dealing with hot water, natural gas, and electricity!

Tank Type Water Heater Maintenance:

Vent (Gas Water Heaters Only)

  • The vent should be the same diameter as the draft diverter on the heater tank.
  • The vent should go generally “up and out” the ceiling.
  • Where is passes through the exterior wall, the vent should be double-walled.
  • Vent sections should be screwed together with a minimum three screws per section.

Note: Bad vent pipe connections can fall apart and lead to carbon monoxide poisoning, the silent and deadly gas!

Temperature & Pressure Relief Valve (T&P Valve)The T&P valve is designed to prevent the heater from exploding if the water pressure or temperature exceeds safe limits.

  • Pull up the handle on the valve and water should flow out and stop when you let go of the handle.
  • The T&P valve has a drain line that should go down to about 6″ from the floor or be plumbed outside your home.

Note: Water leaking out of a T&P drain line can signal a bad T&P valve, high water pressure, or a malfunctioning thermal expansion device.

Water Pressure (All Water Heaters)

  • Water pressure over 80 pounds per square inch (psi) can damage heaters and your piping. It can also damage plumbing appliances, toilets, and your fixtures.

Note: One giveaway that your have high water pressure is when the T&P Valve on the heater starts opening and closing.

Outer Water Heater Metal Shell & Plumbing Fittings

  • Inspect the heater outer sheet metal shell for leaks or rusting.
  • Inspect the plumbing fittings on the heater for corrosion, rust, or water spotting.

Note: Rusty fittings or discolored shell is a telltale sign that a leak is present!

Temperature Control

  • Inspect the heater temperature control dial to insure its set at the correct water temperature.
  • The ideal water temperature is 120° Fahrenheit.

Note: Anything above 120° Fahrenheit greatly increases scalding risk, energy use, and sediment build-up in the bottom of the heater!

Combustion Chamber (Gas Water Heaters)

  • Turn the gas valve control to “pilot position”.
  • Remove the outer access hatch or cover on the side of the heater.
  • Inspect the roof of the chamber for heavy rusting, water marking, or pitting.
  • Return the gas valve control back to the “on position”.

Note: Black soot in the combustion chamber means drafting problems, combustion problems, fume problems, and a fire hazard!

Pedestal Base (Gas Water Heaters)

  • Make sure the pedestal base the heater rests on is stable and supports the unit.
  • The typical pedestal will keep the bottom of the heater at least 18″ off the floor.

Note: A newer water heater may have a “filtered combustion chamber” that is supposed to resolve the need for a pedestal. Check the owner’s manual for your heater.

Drain Valve

  • Open the drain valve to insure that mineral sediment, anode sludge, or rust has not clogged your heaters drain.

Drain Overflow Pan

  • If your heater is on the 2nd floor above living space it should have a drain pan.
  • The drain pan should be plumbed to the outside of your home.
  • Inspect the condition of the drain pan, fittings, and piping to the outside.

Corrosive Fumes (Gas Water Heaters & Tankless Water Heaters)

  • Water heaters draw air in for combustion and the quality of the air is important.
  • Corrosive liquids, ammonia, or acids stored near a heater can lead to corrosive air.

Note: Corrosive air drawn into the burner can prematurely corrode the heater.

Internal Tank Corrosion and Rust-The internal tank of your heater is constructed of steel and glass lined to prevent rust. Sacrificial anode rods are installed in the tank to protect the glass lined internal steel tank from rust. Aluminum/Zinc or magnesium anode rods corrode over time and get used up through an electrolytic process.

Note: Replacing the anode rod can extend the life of the heater but, should be done by a trained, professional service technician.

Sediment Build-up-Sediment is created when hard water is heated. The build-up of sediment in the bottom of the tank can cause the bottom to overheat and melt away the glass lining of the tank. It can drift into recirculating lines, jam open check valves, and cause the recirculating pump to stick until it burns out. Sediment build-up on the bottom of gas water heaters encourages noisy operation. The noise is caused by small amounts of water under the sediment layer turning into steam bubbles, which then collapse violently.

Note: Sediment build-up can reduce the energy efficiency of the heater and void the warranty on some Residential Water Heaters!

Tankless Water Heater Maintenance:

Flushing-Most tankless water heater manufacturers recommend flushing the entire unit every 6 months to 1 year depending upon the water quality. Reference your manufactures recommendation for flushing. Flushing the unit regularly removes any mineral deposits (usually calcium or lime) that may have built up inside the boilers. Manufacturers recommend using a utility pump to circulate 3 or 4 gallons of vinegar or another low-grade acid for 45 minutes to clean out any deposits.

Note: Without the proper equipment this can overwhelm a “Do-It-Yourselfer”!

Water Drain Valve

  • Periodically check the heater’s “in-line filter” to keep grime and debris from building up. The filter is a cylindrical screen.

Note: Consult the manufactures directions for cleaning to avoid injury due to hot water.

Troubleshooting-If a fault occurs with your tankless water heater, an error code will flash on the digital display of the control panel.

Note: If any remedy involves gas or electricity, or you have any doubt about performing the remedy yourself call a qualified service technician! Make sure he is knowledgeable of your brand of heater, has the proper tools to diagnose the problem, and has the parts to repair the unit.