No hot water is one of the most common service calls we run in Durham and Chapel Hill, and the fix depends entirely on whether the unit is gas or electric and what the exact symptom is. Drain Express diagnoses no-hot-water calls same-day and carries the most common replacement parts on the truck.
Electric Water Heater: No Hot Water
No hot water at all on an electric unit usually means the upper heating element has failed, or the upper thermostat has tripped or failed. The upper element heats the top third of the tank and is the first stage of the heating cycle. When it fails completely, the lower element never activates because the aquastat never sees call for heat from the lower thermostat.
Lukewarm water or runs out quickly on an electric unit usually means the lower element has failed. The lower element maintains the bottom two-thirds of the tank temperature. When it fails, the upper element keeps the top portion warm but the overall supply runs out faster than normal.
Tripped reset button on the upper thermostat is a separate failure mode. The ECO (emergency cut-off) button trips when the thermostat senses over-temperature — usually from a failed thermostat that allowed the water to overheat. Resetting without replacing the thermostat typically results in another trip within days.
Gas Water Heater: No Hot Water
Pilot light is out is the most common gas water heater call. On older units with a standing pilot, the thermocouple — the small probe that sits in the pilot flame — fails and cuts gas to the pilot. The fix is thermocouple replacement. On newer units with electronic ignition, a failed igniter or ignition control board produces the same symptom.
Pilot lights but burner does not fire usually means the thermopile (on millivolt systems) or gas valve has failed. The thermopile generates the small voltage that opens the main gas valve. When it degrades, it cannot produce enough voltage to open the valve even though it generates enough to keep the pilot flame visible.
Burner fires but cycles off quickly (short-cycling) usually means a faulty gas valve, a blocked flue, or a combustion air problem. Short-cycling on a gas unit requires diagnosis before parts replacement.
When No Hot Water Means Replace
If the unit is over 12 years old and the repair involves a major component (gas valve, control board, heat exchanger), the repair cost often approaches or exceeds replacement cost. We tell you the numbers before recommending a direction. See Water Heater Replacement Durham NC.
Related Services
- Tank Water Heater Repair
- Water Heater Leaking Repair
- Water Heater Noise Repair
- Water Heater Services Overview