A small number of water heater issues are genuinely safe for a handy homeowner to address — resetting a tripped high-limit button, relighting a pilot on an older gas unit, or adjusting a thermostat setting. But the majority of water heater repairs involve gas lines, electrical components operating at 240 volts, high-pressure systems, or safety devices whose proper function prevents serious injury. Done’s advice: know where the safe DIY line is, and call a licensed plumber for everything beyond it.

What a Homeowner Can Safely Do

There are a handful of tasks that don’t require a licensed plumber and carry minimal risk when done carefully:

  • Adjusting the thermostat: The temperature dial is accessible on most tank units behind a cover plate. Setting it to 120°F is the EPA’s recommended balance between scalding prevention and Legionella inhibition
  • Relighting a standing pilot: Older gas units with a standing pilot (not electronic ignition) have manufacturer instructions on the label; following them exactly is generally safe for homeowners
  • Pressing the reset button: Electric water heaters have a red high-limit reset button on the upper thermostat; if the unit has lost power and no element has burned out, this may restore operation
  • Flushing sediment: Attaching a hose to the drain valve and draining a portion of the tank to clear sediment is within homeowner capability, though it requires care with hot water and the drain valve can seize on older units (see the dedicated flushing FAQ for full guidance)

Where DIY Becomes Risky

Gas water heater repairs beyond relighting a pilot — replacing a thermocouple, gas valve, or burner assembly — involve working on a live gas appliance. Improper connections, cross-threaded fittings, or an incorrectly seated thermocouple can cause gas leaks, incomplete combustion, or carbon monoxide production. Colorado’s altitude compounds combustion issues: a gas appliance that seems to “work” after a DIY repair may be producing elevated CO due to an incomplete combustion mixture, with no visible flame problem to alert you.

Electric water heater element replacement (240-volt circuit) is a step many tutorials describe as DIY-friendly, but it carries real risk. The circuit must be confirmed de-energized with a voltage tester before any contact, the tank must be fully drained before removing the element or the element port will flood the area under pressure, and the element must be torqued correctly to prevent leaks at the gasket. Mistakes at any of these steps cause electrocution risk or water damage. It’s not impossible for an experienced DIYer, but the margin for error is smaller than most tutorials acknowledge.

The Pressure Relief Valve: Never DIY

The temperature and pressure relief (TPR) valve is a critical safety device that opens to release pressure if the tank overheats. If yours is dripping, many online sources suggest simply replacing it — but that dripping is the valve’s signal that system pressure is too high, that the expansion tank has failed, or that the valve itself has lost its calibration. Replacing a dripping TPR valve without diagnosing the underlying pressure cause is dangerous: if the root cause is genuine overpressure and the new valve also fails, the result can be catastrophic.

Colorado’s closed water systems (homes with pressure reducing valves on the main) are especially prone to thermal expansion pressure buildup. Done’s plumbers diagnose TPR valve issues as part of the full pressure system — not as a standalone parts swap.

Permits and Code in Colorado

In most Front Range municipalities, water heater replacement — even if you do the work yourself — requires a permit and inspection. A homeowner permit is available in some jurisdictions, but the inspection process exists to verify the work meets current code, including proper seismic strapping, compliant venting, and a correctly installed expansion tank on closed systems. Unpermitted water heater work can create issues with homeowner’s insurance claims and real estate disclosure requirements.

When to Call Done

If your water heater issue goes beyond thermostat adjustment or pilot relighting, the smarter call is usually to get a professional diagnosis first. Done’s plumbers can tell you whether a repair is cost-effective given the unit’s age and condition, or whether replacement makes more sense — especially in Colorado’s hard-water environment where sediment accelerates wear significantly. Visit our water heater repair page to schedule a diagnostic visit, or if you’re already thinking about replacement, explore your options at water heater services. For ongoing maintenance that extends equipment life, ask about our Care Club membership.