Everything that can go wrong with a tank or tankless water heater — and how to fix it. Our water heater guides cover leaks (from the bottom or the top), no hot water, pilot and ignition problems, relief valve issues, and real 2026 repair-vs-replace costs. Each guide separates safe DIY steps from work that needs a licensed plumber.
Last updated: July 2026 · Reviewed against manufacturer installation guidelines A thermal expansion tank protects your water heater and plumbing from the pressure that builds when water heats and expands. On a closed plumbing system (one with a check valve or pressure reducing valve), an expansion tank is often required by code — and it … Read more
Last updated: July 2026 · Reviewed against A.O. Smith and Rheem service documentation If you have hot water but it runs out too fast, the tank is heating — it just is not keeping up. The usual causes are a broken dip tube, sediment stealing tank capacity, a failed lower heating element (electric), a too-low … Read more
Last updated: July 2026 · Based on 2026 US installed pricing Replacing a water heater costs $1,200 to $2,500 installed for a standard 40–50 gallon tank in 2026, with most homeowners paying around $1,500–$2,000. But that headline range hides a lot: the type you choose (tank, tankless, or hybrid), the size, your home’s existing setup, … Read more
Last updated: July 2026 · Reviewed against A.O. Smith and Rheem operating instructions To turn up the temperature on your water heater, find the thermostat dial (gas) or the thermostats behind the access panels (electric) and raise the setting. The U.S. Department of Energy recommends 120°F as the sweet spot — hot enough for comfort … Read more
Last updated: July 2026 · Reviewed against A.O. Smith and Rheem service documentation A water heater making noise — popping, rumbling, crackling, or a high-pitched whine — is usually telling you about sediment. The most common cause by far is mineral buildup at the bottom of the tank, which is harmless to fix but worth … Read more
Last updated: July 2026 · Reviewed against A.O. Smith and Rheem service documentation The anode rod is the single most important part for extending your water heater’s life — and the most overlooked. This “sacrificial” metal rod corrodes instead of your tank, so when it is used up, the tank itself starts to rust. Replacing … Read more
Last updated: July 2026 · Based on Whirlpool water heater serial number conventions To find the age of a Whirlpool water heater, look at the first four digits of the serial number on the rating plate. Whirlpool water heaters (built by American Water Heaters / A.O. Smith) use a YYWW format: the first two digits … Read more
Last updated: July 2026 · Reviewed against A.O. Smith and Rheem service documentation Flushing your water heater once a year removes the sediment that collects at the bottom of the tank — the stuff behind rumbling noises, lost capacity, and premature tank failure. It takes about an hour, needs nothing but a garden hose, and … Read more
Last updated: July 2026 · Based on 2026 US installed pricing A tankless water heater costs $1,800 to $4,500 installed for a typical whole-home gas unit in 2026, with most homeowners paying around $2,500–$3,500. The unit itself is only part of it — installation often costs as much as the heater, because tankless units frequently … Read more
Last updated: July 2026 · Reviewed against Rinnai, Navien and Noritz maintenance guidelines Tankless water heaters need one thing tank heaters do not: annual descaling. Hard water leaves mineral scale inside the heat exchanger, and left alone it kills efficiency and eventually the unit — which is why manufacturers require documented maintenance to keep the … Read more