The Ultimate Guide to Changing Out a Water Heater

Is Changing Out a Water Heater a DIY Job — or Time to Call a Pro?

Changing out a water heater is something most homeowners will face at least once. Here's the quick answer:

Can you do it yourself?

• Yes — if you have plumbing experience and are replacing an electric unit like-for-like

• Probably not alone — if it's a gas water heater, requires new venting, or involves permit-required work in Utah County

• Call a pro — if your unit is leaking, you smell gas, or you're unsure about any step

Quick overview of the replacement process:

1. Turn off power or gas and the water supply

2. Drain the old tank

3. Disconnect water lines, gas/electrical connections, and venting

4. Remove the old unit and position the new one

5. Connect supply lines, T&P relief valve, and fuel source

6. Fill the tank, test for leaks, and restore power or gas

Most tank water heaters last 8 to 12 years. By the time yours starts showing trouble — rusty water, rumbling noises, puddles on the floor — replacement is usually smarter than repair.

Think of it this way: there's nothing quite like a water heater dying the night before guests arrive for a week-long visit. Knowing what's involved before that happens puts you way ahead.

This guide covers everything — from spotting the warning signs early, to the tools you'll need, to a full step-by-step walkthrough for both gas and electric units. Whether you're a confident DIYer or just want to understand the process before calling a licensed plumber, you're in the right place.

When is Changing Out a Water Heater Necessary?

In April 2026, many homeowners in Northern Utah are finding that their units installed during the building booms of the mid-2010s are reaching their twilight years. While we all wish our appliances lasted forever, a water heater is a pressurized vessel constantly exposed to water and heat—a recipe for eventual wear and tear.

Typically, a tank-style water heater has a lifespan of 8 to 12 years. If your unit is pushing a decade, you’re officially in the "replacement zone." Even if it seems to be working, the internal components are likely corroding. If you aren't sure how old your unit is, we recommend scheduling a professional water heater inspection to assess its health before a catastrophic leak occurs.

Signs Your Unit is Failing

Waiting for a flood in your basement is one way to know you need a new unit, but there are much subtler warnings you should watch for:

• Rusty Water: If your hot water looks like tea or has a metallic scent, the internal glass lining of your tank has likely cracked, allowing the steel to rust.

• Rumbling Noises: As water heaters age, sediment (minerals like calcium and magnesium) settles at the bottom. This sediment hardens, and when the burner or element heats up, the water trapped underneath boils and "pops," creating a loud rumbling sound.

• Visible Leaks: Any moisture around the base of the tank is a red flag. While some "leaks" are actually just condensation or a loose fitting that needs a simple water heater repair, a leak from the tank itself is incurable.

• Inconsistent Heat: If your showers are getting shorter or the water never seems to reach the temperature it used to, your heating elements or gas burner may be failing.

For a deeper dive into diagnosing these issues, you can check out Everything You Need to Know to Replace a Water Heater - This Old House, which highlights how proactive replacement can save you from emergency costs.

Choosing Between Repair and Changing Out a Water Heater

When we visit homes in Provo or Salt Lake City, we often get asked: "Can't you just fix it?"

We use the 50% Rule: If the cost of the repair is more than 50% of the cost of a new unit, or if the unit is over 10 years old, changing out a water heater is the better financial move. Newer units have a much higher Energy Factor (EF). For example, a modern electric heat pump water heater can use one-third to one-half the electricity of an older resistance model.

Investing in a water heater replacement isn't just about stopping a leak; it's about upgrading your home's efficiency and lowering your monthly utility bills.

Preparation: Tools, Materials, and Safety Precautions

Before you even touch a pipe wrench, you need to have your supplies ready. This isn't a project where you want to be running back and forth to the hardware store while your house has no water.

Essential DIY Tool List:

• Pipe wrenches (two are better than one for leverage)

• Non-contact voltage tester (for electric units)

• Screwdrivers and pliers

• Tubing cutter or hacksaw

• Garden hose (for draining)

• Teflon tape and pipe joint compound (gas-rated if applicable)

• Soldering kit (if using copper) or push-to-connect fittings

Safety Precautions for Changing Out a Water Heater

Safety is our number one priority. This project involves the "Big Three" of home hazards: water, electricity, and gas.

1. Electricity: Electric water heaters usually run on 240-volt circuits. This is enough to be lethal. Always turn off the breaker and use a voltage tester to verify the wires are "dead" before touching them.

2. Gas Leaks: If you have a gas unit, an improper connection can lead to leaks or even explosions. Always use a soapy water solution to check every joint for bubbles after installation.

3. Carbon Monoxide: Gas units must be vented perfectly. If the vent isn't aligned or has gaps, odorless, deadly carbon monoxide can backdraft into your home.

4. Scalding: Water inside a tank can be 140°F or hotter. Turn the unit off at least two hours before draining to avoid burns. Proper water heater maintenance involves checking these safety features annually.

Permits and Local Code Compliance

In Northern Utah, changing out a water heater usually requires a building permit. Why? Because local inspectors want to ensure your home won't burn down or flood.

Key code requirements often include:

• Seismic Straps: Since we live in an earthquake-prone region, your tank must be strapped to the wall studs to prevent it from tipping over during a tremor.

• Thermal Expansion Tanks: If you have a "closed" plumbing system (common in modern homes), you must have an expansion tank to handle the extra pressure created when water heats up.

• Drain Pans: If your heater is located in a finished area or attic, a drain pan is required to catch leaks.

Keeping up with water heater tune-ups can help you stay compliant with these evolving local codes.

The Step-by-Step Process of Changing Out a Water Heater

Ready to get to work? Follow these steps carefully. If at any point you feel overwhelmed, we offer 24/7 support for homeowners who get stuck mid-project.

Removing the Old Unit

1. Shut it Down: Turn off the gas valve or flip the electrical breaker. Turn off the cold water supply valve leading into the tank.

2. Drain the Tank: Attach a garden hose to the drain valve at the bottom of the tank. Run the other end to a floor drain or outside. Open a hot water faucet elsewhere in the house to break the vacuum and let the water flow. Tip: If the water only trickles, sediment might be blocking the valve. Try poking a stiff wire into the opening to clear it.

3. Disconnect: Use your pipe wrenches to disconnect the water supply lines. If they are soldered copper, you'll need to cut them. For gas units, disconnect the gas line and the exhaust vent hood.

4. The Move: Once empty, the tank will still be heavy (about 150 lbs). Use an appliance dolly to move it out. This is a great time to consider upgrading to a tankless water heater if you want to save space and never run out of hot water again.

For more visual details, How to Replace a Water Heater In Your Home in 7 Steps provides an excellent breakdown of the removal phase.

Installing the New Gas or Electric Water Heater

1. Positioning: Set the new unit in place. Use plastic shims to ensure it is perfectly level. This prevents stress on the pipes and ensures the burner (for gas) or elements (for electric) work correctly.

2. T&P Valve: Most new heaters like the Rheem 50 Gallon Water Heater come with a Temperature & Pressure (T&P) relief valve. If not, you must install one. This is the most important safety feature—it prevents the tank from exploding if the pressure gets too high.

3. Discharge Pipe: Attach a copper or CPVC pipe to the T&P valve, extending it to within 6 inches of the floor. Never plug this pipe!

4. Wiring/Gas: For an electric water heater, connect the ground wire to the green screw and the two power wires to the heater's leads using wire nuts. For gas, reconnect the gas line using a new flexible connector and plenty of pipe dope on the threads.

Managing Pressure and Expansion Tanks

If your home has a pressure-reducing valve or a check valve, you have a "closed system." When water heats up, it expands. In a closed system, that pressure has nowhere to go, which can damage your pipes or the tank's inner liner.

An expansion tank provides a "cushion" for this extra volume. You must "charge" the expansion tank with air to match your home's water pressure (usually 50–60 PSI) before installing it.

Expansion Tank Sizing Guide:

Heater Capacity	Expansion Tank Size
Up to 50 Gallons	2-Gallon Tank
50 to 100 Gallons	5-Gallon Tank

Final Connections and Testing for Leaks

With the tank in place, it's time to hook up the water. We recommend using dielectric unions or plastic-lined nipples to prevent "galvanic corrosion"—a fancy term for what happens when two different metals (like copper pipes and a steel tank) touch and start to rust.

1. Connect Water Lines: Use flexible stainless steel or copper connectors for an easier fit. If you're using push-to-connect fittings, ensure the pipe is cut square and deburred.

2. The "Dry Fire" Warning: CRITICAL: Never turn on the power or gas until the tank is completely full of water. If you turn on an electric heater while the tank is empty, you will burn out the upper heating element in seconds.

3. Fill and Flush: Turn the cold water supply back on. Keep a hot water faucet open in the house until water flows steadily without "burping" air. This ensures the tank is full.

4. Test for Leaks: Check every water connection. For gas units, brush a mixture of dish soap and water onto the gas joints. If you see growing bubbles, you have a leak—shut off the gas and tighten the connection immediately.

Professional water heater installation ensures these final checks are done with precision instruments, giving you total peace of mind.

Post-Installation Checklist

Before you call it a day, run through this final list:

• Thermostat Setting: Set the temperature to 120°F. This is the "sweet spot" that prevents bacterial growth while protecting children and the elderly from scalding. It also saves about 10% on energy costs compared to higher settings.

• Venting Check: For gas units, hold a smoking match or incense stick near the draft hood while the burner is on. The smoke should be sucked up into the vent. If it blows back into the room, you have a dangerous venting issue.

• Recovery Rate: Give the unit time. Gas units take about 30 minutes to heat up, while electric units may take an hour.

If you find that your family’s demand for hot water is still too high, you might consider a high-performance unit like the Navien NPE-240S Tankless Water Heater, which offers an endless supply of hot water.

Frequently Asked Questions about Water Heater Replacement

Can I change a water heater by myself?

Yes, if you are comfortable with basic plumbing and electrical work. However, gas water heater replacement is significantly more dangerous due to the risks of fire, explosion, and carbon monoxide poisoning. Many local codes in Northern Utah require a licensed professional to handle gas line connections. If you feel even slightly unsure, it's better to call us than to risk your safety.

How much does it cost to replace a water heater in 2026?

In 2026, the average cost for a professional replacement ranges from $900 to $1,800. This includes the unit, labor, and disposal of the old tank. High-efficiency models or tankless conversions can cost more upfront ($2,500–$4,500) but offer significant long-term savings on your energy bills.

How do I dispose of my old water heater?

You can't just leave it on the curb! Most professional plumbers (like us) include disposal in their service. If you're doing it yourself, you can take it to a local recycling center or scrap yard. Some municipal trash services will pick them up for a small fee (usually around $25), but you often have to schedule this in advance.

Conclusion

Changing out a water heater is a major home improvement task, but with the right preparation and respect for safety, it’s a manageable one. Whether you decide to tackle this project yourself or hire a professional, the most important thing is not to wait until your basement is flooded to take action.

At Admiral Plumbing, Heating & Cooling, we’ve been helping our neighbors in Provo and throughout Northern Utah stay in hot water (the good kind!) for years. With our 24/7 emergency service and A+ BBB rating, we’re here to help with everything from a simple Rheem 40 Gallon Water Heater swap to a complex Noritz EZ111DV NG Tankless Water Heater installation.

Need a hand or just want a pro to handle the heavy lifting? More info about water heater services is just a click away, or give us a call today!