Kenmore water heater troubleshooting follows standard residential tank diagnostics — Kenmore units are State Industries or A.O. Smith underneath, so the same diagnostic logic applies. Below: symptom-by-symptom troubleshooting.
Symptom: No hot water at all
Electric models
- Verify breaker is on (most common; people often miss the breaker after a power outage)
- Press the high-limit reset button on the upper thermostat. If it trips again within minutes, replace upper thermostat ($30, 30-min DIY)
- Test both elements with a multimeter. Disconnect power. With one wire removed from each element, measure Ohms across the element terminals. Healthy: 10–16 ohms. Infinite = burned out, replace.
Gas models
- Verify pilot is lit. Most Kenmore gas units have a viewing window or simple sight glass.
- If no pilot: follow lighting procedure on the unit (typically: gas valve to "Pilot," push and hold, light with match or piezo igniter, hold 30 seconds, release).
- If pilot won't stay lit: thermocouple failure (most common). $20–40 part, $80–150 labor.
- If pilot lit but burner won't fire: gas valve failure or weak thermopile.
Symptom: Lukewarm or partial hot water
Lower element failed (electric) or burner issue (gas). For electric: test lower element specifically. For gas: verify burner orifice is not clogged with debris.
Symptom: Hot water runs out quickly
Two common causes:
- Cracked dip tube: cold water enters at the top instead of the bottom, mixing immediately with hot. Pull dip tube, inspect for cracks or shortening. Replace if cracked ($10 part).
- Thermostat set too low: verify both thermostats are at 120°F (or per local code).
Symptom: Water around base
Diagnose source by inspection:
- T&P discharge tube: normal if pressure spiked; check expansion tank charge. If continuous, replace T&P.
- Drain valve: tighten or replace.
- Dielectric union: re-tape and re-tighten.
- Tank weld: warranty claim required, tank replacement.
Symptom: Banging or popping noise
Sediment in the bottom of the tank causing water to boil under it. Annual flush (see maintenance guide). For severe accumulation, full drain-and-flush.
Symptom: Smelly hot water
"Rotten egg" smell = sulfur reduction by anode rod reacting with bacteria. Solution:
- Replace magnesium anode with aluminum-zinc alloy (kills the sulfur reaction)
- Sanitize tank with hydrogen peroxide (3 cups of 3% peroxide, fill tank, sit 4 hours, flush)
- For chronic issues, install whole-house chlorinator
Symptom: T&P valve continuously discharges
Three possibilities:
- Failed T&P valve — replace ($25, 30-min DIY)
- Pressure spike from thermal expansion — install or recharge expansion tank
- Thermostat stuck closed, runaway heating — replace thermostat (electric) or gas valve (gas)
When to call a pro
Gas valve replacement, leak from tank weld, refrigerant or compressor on hybrid units, electrical issues beyond standard element/thermostat. Sears Home Services (where active) or any licensed plumber familiar with State/A.O. Smith manufacturing.