The two parts behind most electric failures
Thermostat & Heating Element Replacement in Denver, CO
Lukewarm water, hot water that runs out in ten minutes, or a reset button that keeps tripping — these are element and thermostat symptoms, and both are same-day repairs.
- Upper and lower elements
- Thermostat and ECO replacement
- All voltages and wattages stocked
- Recovery verified before we leave
An electric water heater has five electrical parts that matter: two heating elements, two thermostats, and the ECO high-limit switch built into the upper thermostat. When hot water misbehaves without a leak, the cause is almost always one of those five.
Because the upper circuit controls power to the whole unit, a fault up top produces no hot water at all, while a fault at the bottom produces hot water that vanishes quickly. That single distinction narrows the diagnosis before we open a panel.
Matching symptom to part
| What you experience | Most likely cause | Typical fix |
|---|---|---|
| No hot water whatsoever | Tripped ECO, failed upper element or upper thermostat | Diagnose cause, then replace the failed part |
| Hot water for 5–15 minutes, then cold | Failed lower element | Replace lower element and gasket |
| Lukewarm water all day | Failed upper element, or thermostat out of calibration | Replace element or thermostat |
| Reset button trips repeatedly | Shorted element or stuck thermostat contacts | Test both, replace the faulty component — never just reset |
| Water far too hot | Thermostat stuck closed or set too high | Replace thermostat, set to 120°F |
| Breaker trips on call for heat | Element shorted to ground | Replace element, inspect wiring |
How we replace an element properly
Isolate and verify dead
Breaker off, then voltage verified absent at the terminals with a meter. Never assume a labeled breaker is the right one.
Drain enough to clear the element
Below the element port — the full tank is not always necessary on an upper element.
Remove and inspect
A scaled element tells us the tank needs a flush too; a burned-out element with clean scale tells us it simply aged out.
New element, new gasket
Always a fresh gasket. Wattage and voltage matched to the tank's rating plate — a mismatched element either underperforms or trips the breaker.
Refill and purge before energizing
The single most important step. Energizing an element in air destroys it in seconds.
Verify recovery
We measure the temperature rise to confirm the element is actually working before we call it done.
Thermostats, calibration and the ECO
Water heater thermostats are surface-mounted: they read tank temperature through the steel wall, held flat by a spring clip. A thermostat that has been knocked loose, or reinstalled without seating properly, reads the room instead of the water — producing wildly wrong temperatures with no component actually failed.
The ECO (energy cut-out) is the red reset button on the upper thermostat. It opens when water exceeds roughly 180°F. A single trip after a power event can be benign. A repeat trip is not: something is holding an element energized past setpoint, and that is a scald and pressure hazard. We find the cause instead of resetting it and leaving.
If you have already pressed the reset more than once, tell us — it changes what we test first, and it means the fault is live rather than historical.
Costs and what's worth doing at the same time
Element replacement runs about $180–$400 for one, $320–$550 for both with gaskets. Thermostats run $180–$350. If one element has failed on a tank past six years, replacing both while the unit is drained saves a second call and a second drain.
Two things worth bundling: a full flush (the tank is drained anyway, and sediment is frequently what killed the lower element), and an anode rod check.
Frequently asked questions
How do I know if my heating element is bad?
Test for continuity across the element terminals with power off. An open circuit means a failed element. Resistance to ground means it has shorted. If hot water runs out unusually fast, the lower element is the prime suspect; if there is no hot water at all, look at the upper.
Can both elements fail at once?
It happens, usually from a power surge or heavy scale. More often one fails and the second is close behind, which is why replacing both together while the tank is drained is often the better value.
Why does my water heater reset button keep tripping?
The ECO trips at roughly 180°F. Repeated trips mean a shorted element or a thermostat whose contacts are stuck closed. Continuing to reset it is unsafe — that switch is the final protection against dangerously hot water.
What temperature should the thermostats be set to?
120°F on both, with the upper and lower matched. Unequal settings make the elements fight each other and produce inconsistent temperatures.
Is it worth replacing an element on an old water heater?
Under about ten years, yes — it is inexpensive and buys years. Past twelve, the tank itself is the component nearing end of life, and the money is usually better spent on replacement.
Cold shower this morning? We can be out today.
Tell us what the heater is doing and we will give you a straight answer on the phone — repair, replace, or wait.