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Water Heaters How-To Guides

Master essential water heater maintenance and repair tasks with our step-by-step guides. From routine maintenance to troubleshooting, these tutorials help you keep your system running efficiently and extend its lifespan.

All Water Heaters Guides 11

How to Adjust Water Temperature

easy

Set your gas or electric water heater thermostat to the right temperature for comfort, safety, and lower energy bills -- plus how to verify the actual output with a thermometer.

5 - 10 minutes $0
What you need: Flathead screwdriver (for electric water heater thermostat adjustment) Phillips screwdriver (for access panel screws on electric units) Non-contact voltage tester (for verifying power is off on electric units) Cooking thermometer or instant-read thermometer (for verifying water temperature)

How to Choose the Right Size Water Heater

easy

Calculate the right water heater size so you never run out of hot water -- covers first-hour rating for tanks, GPM for tankless, quick sizing charts, and the mistakes that leave people taking cold showers.

N/A (buying guide) $800 - $3,000+ depending on type and size
What you need: Calculator (for adding up peak hour demand) Kitchen thermometer (for checking incoming water temperature if sizing a tankless unit)

How to Flush Your Water Heater

easy

Flush sediment from your tank water heater to cut energy bills, eliminate rumbling noises, and add years to its life -- the most important maintenance task most homeowners skip.

30 - 60 minutes $0 (no parts needed)
What you need: Garden hose (long enough to reach a drain or outside) Flathead screwdriver (some drain valves use a screwdriver slot instead of a handle) Work gloves (the water is extremely hot) Bucket (for catching initial drips when connecting/disconnecting the hose) Channel-lock pliers (optional, for stubborn drain valves) Brass hose cap (optional, $2, for sealing a slightly dripping drain valve after the flush)

How to Insulate Your Water Heater

easy

Cut your water heating bill by insulating the tank with a blanket and wrapping the first 6 feet of pipe -- a $20-50 project that pays for itself within a year.

30 - 60 minutes $20 - $50 for insulation blanket and pipe sleeves
What you need: Water heater insulation blanket kit ($15-30, sized for your tank) Pre-slit foam pipe insulation sleeves (match pipe diameter) Tape measure (for measuring pipe runs and blanket cutouts) Utility knife or scissors (for cutting blanket and pipe insulation) Foil tape (for securing blanket and pipe insulation seams) Marker (for marking cutout locations on the blanket)

How to Replace a Water Heater

hard

Replace a tank-style water heater from start to finish -- drain, disconnect, swap the unit, reconnect plumbing and gas or electric, and test for leaks and proper operation.

3 - 6 hours $800 - $3,000+ for unit + materials
What you need: Pipe wrenches (two, for disconnecting threaded pipe) Adjustable wrench (for supply line connectors) Garden hose (for draining the old tank) Pipe cutter (if cutting copper pipe) SharkBite fittings or soldering kit (for copper pipe connections) Flexible water heater connectors (braided stainless steel, 2 needed) Dielectric unions or nipples (to prevent galvanic corrosion) Non-contact voltage tester (for electric units) Gas leak detector solution or soapy water (for gas units) Level (for checking the tank is plumb) Hand truck or appliance dolly (for moving the heavy tanks) Teflon tape (gas-rated yellow for gas connections)

How to Test Pressure Relief Valve

easy

Test your water heater's T&P relief valve in 2 minutes to make sure it will actually open when it matters -- plus how to replace a failed valve.

5 - 10 minutes $0 (testing); $15 - $30 for replacement valve
What you need: Bucket (for catching test discharge water) Gloves (hot water protection) Pipe wrench (for valve replacement, if needed) Replacement T&P valve ($15-30, matching pressure/temperature/thread size) Teflon tape (for new valve threads) Garden hose (for partial tank drain during replacement)

How to Flush a Water Heater

easy

Drain sediment from your water heater tank to restore heating efficiency, reduce noise, and extend the unit's lifespan. 30-minute annual maintenance task.

30 - 45 minutes $0
What you need: Garden hose (long enough to reach a drain or outside) Flathead screwdriver (for breaking up sediment at the valve) Bucket (if no floor drain available) Brass hose cap (backup in case drain valve leaks) Gloves (water is hot)

How to Install an Expansion Tank

moderate

Install a thermal expansion tank on your water heater to absorb pressure spikes, protect pipes, and meet code. A $30-50 part that prevents serious damage.

30 - 60 minutes $30 - $50 for the tank; $150 - $300 with a plumber
What you need: Thermal expansion tank (2-5 gallon, sized to your water heater) Tee fitting (matching your pipe type and size) Teflon tape Adjustable wrench Pipe cutter (if cutting into the cold water line) Bicycle pump or tire inflator (for pre-charging the tank) Tire pressure gauge Water pressure gauge ($10-15, for checking system pressure) Mounting bracket or plumber's strap (to support the tank)

How to Light a Water Heater Pilot

easy

Relight a gas water heater pilot light safely. Takes 5 minutes once you know the sequence. Covers both manual and electronic ignition models.

5 - 10 minutes $0
What you need: Long-reach lighter or fireplace matches (manual ignition models only) Flashlight (to see through the viewport) Soapy water and brush (for leak testing after relighting)

How to Replace a Thermocouple

easy

Fix a pilot light that will not stay lit by replacing the thermocouple -- the $10 safety sensor that tells the gas valve to stay open. 15-minute job.

15 - 30 minutes $8 - $20
What you need: Replacement thermocouple (universal or brand-specific) 7/16 inch wrench or adjustable wrench Long-reach lighter or fireplace matches Soapy water and brush (for leak testing) Flashlight

How to Replace an Anode Rod

moderate

Swap the sacrificial anode rod in your water heater to prevent tank corrosion, eliminate rotten egg smell, and extend the unit's lifespan by years. $20-30 part.

30 - 45 minutes $20 - $30
What you need: Replacement anode rod (magnesium, aluminum, or powered) 1-1/16 inch socket and breaker bar (or large adjustable wrench) Teflon tape Penetrating oil (for seized rods) Towels and bucket Garden hose (optional, if draining the tank first)