No hot water is more than an inconvenience — it disrupts your entire household. STL Plumbing Pros diagnoses and repairs water heaters that won't heat, run out of hot water too quickly, or produce only lukewarm water. We carry common replacement parts on our trucks for same-day repairs in most cases. If the unit is beyond repair, we handle same-day water heater replacement too.
Common Causes — Gas vs. Electric
Gas Water Heater
- • Pilot light out — thermocouple may need replacement
- • Gas control valve failure — no gas reaching the burner
- • Sediment buildup — insulates water from burner flame
- • Broken dip tube — cold water mixes into hot outlet
Electric Water Heater
- • Tripped reset button — high-limit safety switch activated
- • Failed heating element — upper or lower element burned out
- • Faulty thermostat — element not receiving signal to heat
- • Sediment on element — reduces heat transfer efficiency
Our Diagnostic Process
Systematic Diagnosis
We check the fuel supply, pilot/ignition system, thermostat settings, heating elements (electric), gas valve operation, and dip tube condition. No guessing — methodical testing.
Explain & Quote
We tell you exactly what's wrong, what it costs to fix, and whether repair or replacement makes more sense given the unit's age and condition.
Repair Same Day
Common parts are on the truck. Most water heater heating issues are resolved in a single visit — you have hot water before we leave.
Repair Pricing
| Repair | Price | Details |
|---|---|---|
| Thermocouple replacement (gas) | $125–$225 | Most common fix for pilot light that won't stay lit. |
| Gas control valve replacement | $200–$400 | Controls gas flow to burner — replaced when thermocouple isn't the issue. |
| Heating element replacement (electric) | $150–$300 | Upper or lower element — diagnosed with multimeter testing. |
| Thermostat replacement (electric) | $125–$250 | Controls element activation — tested before element replacement. |
| Dip tube replacement | $150–$300 | Broken dip tube delivers cold water to the top of the tank. |
Why Choose STL Plumbing Pros?
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Accurate Diagnosis
We test systematically — thermocouple, gas valve, elements, thermostats — so we fix the actual problem, not just the symptom.
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Parts on the Truck
We carry thermocouples, heating elements, thermostats, and gas valves. Most repairs completed in a single visit.
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Honest Repair vs. Replace Advice
If your 12-year-old water heater needs a $400 repair, we'll tell you replacement might be the smarter investment.
What Our Customers Say
"No hot water Monday morning. Plumber was here by 10am, diagnosed a bad thermocouple, replaced it, and we had hot water by lunchtime."
"Electric water heater stopped heating. Lower element was burned out. Replaced in under an hour — very knowledgeable technician."
"Appreciated the honest assessment. Unit was 14 years old and they recommended replacement instead of an expensive repair. Right call."