Gas water heater failures usually come down to one of a handful of components: the thermocouple or flame sensor, the gas control valve, the pilot assembly, or the burner itself. At Denver's elevation, a gas unit fitted with the wrong altitude-rated orifice can also show symptoms that look like a component failure but are actually a combustion setup issue — something we specifically check for, since it's easy for a generalist plumber unfamiliar with high-altitude installs to miss.
Venting problems are the other Denver-specific issue we see often in older Sherrelwood mechanical closets: a partially blocked or improperly sloped flue can cause a pilot to blow out repeatedly even when the thermocouple itself is fine.
Common gas water heater symptoms
- Pilot light won't stay lit, or goes out repeatedly
- Burner won't ignite even with a lit pilot
- You smell gas near the unit (leave the area and call your gas utility immediately, then us)
- Water isn't reaching full temperature despite the burner running
- Sooty or yellow burner flame instead of blue
OUR GAS REPAIR PROCESS
What happens during this service
Safety check first
We check for gas leaks and proper venting before testing any other component.
Component testing
The thermocouple/flame sensor, gas control valve, and burner assembly are tested individually to isolate the actual failure.
Altitude & venting check
We confirm the orifice sizing is correct for Denver's elevation and that venting is clear and properly sloped.
Repair & relight
The failed component is replaced, the unit is relit, and we confirm a clean blue flame and full heat cycle.
PRICING
What affects gas repair cost
We quote a flat rate on-site before starting any work. These are the main factors that move price up or down for this service in Sherrelwood:
- Which component failed (thermocouples are lower-cost; gas control valves are higher-cost)
- Whether a venting correction is needed in addition to the component repair
- Unit age and part availability
FAQ
Common questions about this service
Is a pilot light that won't stay lit dangerous?
Not by itself — it's a safety feature working correctly by shutting off gas flow when the flame sensor doesn't detect a flame. The underlying thermocouple or venting issue is what needs repair.
What if I smell gas near my water heater?
Leave the area, don't operate any switches, and call your gas utility's emergency line first, then us. Do not attempt to relight the pilot yourself.
Why does a blue vs. yellow flame matter?
A clean blue flame indicates proper combustion; a yellow or sooty flame can indicate a dirty burner or combustion air problem, and can also point to carbon monoxide risk — worth an inspection promptly.
Do older gas units need different parts than new ones?
Sometimes — thermocouples and gas valves vary by model and age, which is why we carry a range of common parts rather than a single generic kit.
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