Water Heater Element Replacement — DIY & When to Call

If you’re getting less hot water than you used to, or running out of hot water faster, the most common culprit on an electric water heater is a failed heating element. After 40 years of water heater work in Burleson, I’ve replaced more elements than I can count — and on a heater that’s otherwise in good shape, it’s one of the more cost-effective repairs in plumbing.

This post is about electric water heaters (the kind with two heating elements inside the tank). If you have a gas water heater, your problems are different — see my post on gas water heater pilot light problems instead.

Electric Water Heater vs. Gas — A Quick Check

Before going further, make sure you have the right kind of heater:

Electric water heater: Has a power cable going into the side. No flue or vent pipe on top. No gas line. Heats water with two electric elements inside the tank.
Gas water heater: Has a gas line, a vent pipe going up through the roof, and a pilot light or igniter.

The rest of this post is for electric.

How Heating Elements Work

Most residential electric water heaters have two heating elements:

Upper element — about 1/3 down from the top of the tank
Lower element — about 1/3 up from the bottom

They work together:

When the tank is fully cold, the upper element fires first so you get hot water at the top quickly
Once the top half is hot, the lower element fires to heat the bottom half
Each element has its own thermostat that switches it on and off

Why this matters for diagnosis: if you have “a little bit of hot water and then it runs cold fast,” your lower element is bad. If you have no hot water at all, your upper element is bad (or there’s a power issue).

Signs of a Bad Heating Element

Less hot water than usual — most common
Hot water runs out fast — usually the lower element
No hot water at all — usually the upper element (or no power)
Breaker keeps tripping — possible short in an element
Tank still works but takes a long time to heat — one element underperforming

What’s NOT an element problem:

Popping or rumbling sound when heating → sediment buildup at the bottom of the tank (see below)
Smelly hot water → bacterial contamination or anode rod issue
Visible leak from the tank → tank corrosion, time for a new water heater

Diagnose Which Element Failed (Without a Multimeter)

Even without test equipment, you can usually narrow it down:

Lots of hot water that quickly turns cold = lower element failed (you’re getting the top half from the upper element, then it runs out)
Lukewarm water from the start = upper element failed
No hot water at all, breaker tripped = could be a shorted element or thermostat
No hot water, breaker NOT tripped = upper thermostat may be tripped (reset button is under the upper access panel)

Electrical Safety First

Water heaters run on 240 volts. Working on one with the power still on is genuinely dangerous. Before opening any access panels:

Turn off the breaker labeled for the water heater
Confirm power is off with a voltage tester at the heater itself — don’t trust the label alone
Keep the breaker off the entire time you’re working

DIY: Testing an Element with a Multimeter

Tools:

Phillips screwdriver
Multimeter
Voltage tester (separate from multimeter, for safety verification)

Steps:

Kill power at the breaker. Confirm with a voltage tester at the heater.
Remove the upper and lower access panels (one or two screws each).
Move the insulation aside and lift the plastic safety cover.
Disconnect the two wires from one element (loosen the screws holding the wires).
Set the multimeter to Ohms (Ω).
Touch the probes to the two element terminals:
- Reading of 10–30 ohms = element is good
- Reading of 0 or infinity = element is bad
Then touch one probe to a terminal and the other to the metal tank:
- Should read infinity (no continuity)
- Any reading = element is shorted to ground, needs replacement
Repeat for the other element.

This tells you definitively which element to replace.

DIY: Replacing a Water Heater Element

If you’re comfortable with the testing above, replacement is similar work.

Tools:

Garden hose
Phillips screwdriver
1-1/2″ socket or element wrench (~$10 at any hardware store)
Bucket
Voltage tester
New element matching your heater’s voltage and wattage (typically 240V, 4500W)
New gasket (usually included with the new element)

Steps:

Turn off the breaker. Verify with voltage tester.
Shut off the cold water supply to the heater.
Open a hot water faucet somewhere in the house to relieve pressure.
Drain the tank by connecting a hose to the drain valve and running it to a drain or outside. Takes 20–30 minutes for a 40-gallon tank.
Remove the access panel, insulation, and safety cover at the failed element.
Disconnect the wires from the element (note where each goes).
Unscrew the element with the element wrench. Counterclockwise.
Remove the old element and gasket. Clean the threads on the tank.
Install the new element with the new gasket. Hand-tighten first, then snug with the wrench. Don’t overtighten.
Reconnect the wires to the element terminals.
Refill the tank. Close the drain valve, turn the cold supply back on. CRITICAL: Open a hot water faucet and leave it running until water flows steadily — this prevents firing a dry element, which destroys it in 30 seconds.
Replace insulation, safety cover, and access panel.
Restore power at the breaker and wait 30–60 minutes for the water to heat.

The most common DIY mistake: turning power back on before the tank is completely refilled. A dry element burns out instantly, and you’ll be replacing the new one too.

Sediment Buildup vs. Element Failure (Different Problem)

If you’re hearing popping, crackling, or rumbling from your water heater, that’s not an element problem — that’s sediment.

DFW has hard water. Minerals settle to the bottom of the tank over time and form a thick layer of sediment. When the lower element fires up underneath that layer, water trapped in the sediment boils, creating the popping sound.

The fix is to flush the tank:

Shut off the cold supply
Connect a hose to the drain valve
Open a hot water faucet to break the vacuum
Drain the tank fully
Briefly turn the cold supply on and off a few times to flush remaining sediment
Refill and restart following the dry-element prevention steps above

Heavy sediment can shorten the life of the lower element. If your heater is popping AND losing efficiency, flush it.

When to Call a Plumber

Call us if:

You’re not comfortable working with 240V electricity — totally reasonable
The breaker keeps tripping even after element replacement
The element won’t unscrew because of corrosion
You don’t have a multimeter and want to skip the diagnosis
You see visible water around the base of the heater — that’s a tank issue, not an element
Your heater is more than 10 years old with multiple recent problems

When to Replace the Whole Heater Instead

If your water heater is:

More than 12 years old AND giving multiple problems
Showing visible rust or corrosion at the base
Leaking water anywhere
In need of a second element replacement within a year

…it’s usually smarter to replace the whole unit. New water heaters are more efficient, have better warranties, and won’t surprise you with a flood in your garage.

A Word From Don

If you’re not sure whether you have an element problem or something more serious, give us a call. Element replacement is one of the cheaper water heater repairs — most are same-day service on most plumbing calls. Free phone estimate before we head out.

Serving Burleson, Crowley, Joshua, Alvarado, Keene, Everman, and all of South DFW within about 20 miles of Burleson.

Call Don: 817-447-2654