Common Water Heater Problems for Homeowners

If your showers run cold, your tank pops and rumbles, or you see a mysterious puddle near your water heater, you’re not alone. Water heaters are workhorses, and Pasadena’s hard water and mix of older homes can accelerate wear and tear.

This homeowner-friendly guide from Pershing Plumbing covers the most common water heater problems, what you can safely check yourself, how to prevent breakdowns, and when to call our Pasadena Plumbing pros for fast, code-compliant service.

Quick Takeaways

Hard water in Pasadena causes mineral scale that reduces hot water and efficiency.
Annual flushing, anode rod checks, and expansion tank testing extend water heater life.
If your T&P valve is discharging, or you smell gas, shut it down and call Pershing Plumbing immediately.
Repeated outages, multi-symptom issues, or any tank leak are signals to contact our Pasadena Plumbing team.

Common Water Heater Problems (and what to do first)

No hot water at all

Gas heaters: Check the gas supply valve is open, verify the pilot light is lit or that the electronic igniter clicks, and look for error lights on newer units. A failed thermocouple/thermopile, gas control valve, or igniter can be the culprit.
Electric heaters: Inspect the breaker and press the high-limit reset button (usually behind a small panel). One failed heating element or thermostat can also shut down heat.
DIY check: Confirm power or gas is on and the thermostat is set between 120–125°F. If it trips again or won’t light, call Pershing Plumbing. Gas diagnostics and element/thermostat testing require proper tools and safety procedures from our Pasadena Plumbing technicians.

Not enough hot water or short showers

Likely causes: Sediment buildup eating into tank capacity, thermostat set too low, a failing heating element (electric), broken dip tube letting cold and hot mix, or simply an undersized water heater for your household.
Quick fixes: Raise the thermostat slightly (120–125°F is typical). Stagger high-demand tasks. If the problem is new and water is also noisy, sediment is a strong suspect.
Professional help: Our Pasadena Plumbing team can flush the tank, replace elements or dip tubes, and size a right-fit replacement if your needs have outgrown the tank.

Water temperature swings (too hot, too cold, or inconsistent)

Causes: Scaling on sensors and heat exchangers, a faulty mixing valve, crossover from a bad faucet cartridge, or recirculation system settings out of tune. Tankless heaters can show a “cold-water sandwich” if not maintained.
DIY check: Test one fixture at a time. If hot water drops when a different faucet runs, you may have a crossover issue.
Solution: Pershing Plumbing can diagnose mixing valves, descale tankless units, and balance recirculation pumps and timers for stable temps.

Discolored or smelly hot water

Rusty/brown hot water only: Internal corrosion or an anode rod at end-of-life. If both hot and cold are brown, the issue may be municipal or your home’s piping.
Rotten egg/sulfur smell: Common with magnesium anode rods and certain water chemistries. Bacteria interact with the rod and create odor.
Fixes: Our Pasadena Plumbing pros can replace the anode with an aluminum-zinc rod, sanitize the tank, and flush sediment. If the tank is heavily corroded, replacement may be safest.

Popping, rumbling, sizzling, or whistling noises

Popping/rumbling: Sediment traps steam at the bottom of the tank.
Sizzling: Water dripping on a hot burner (gas) or around elements (electric).
Whistling: High pressure or a partially closed valve.
Action: Schedule a professional flush and scale removal. Pershing Plumbing can also check gas burner alignment, venting, and pressure to quiet the system and improve efficiency.

Leaks, puddles, or T&P valve discharge

Small drips at fittings: Often loose connections or a failing drain valve.
Water from the T&P (temperature and pressure) valve: High pressure, overheating, or a failed expansion tank can force the valve to open by design.
Tank body leak: Internal failure—replacement is usually the only safe option.
Safety first: Turn off power or gas and the cold-water supply. If the T&P is discharging hot water or you see signs of overheating, call Pershing Plumbing immediately. Our Pasadena Plumbing experts will test system pressure, the expansion tank, and the safety controls.

High energy bills or slow recovery

Culprits: Sediment insulation at the bottom of the tank, failing elements or thermostats, uninsulated hot lines or recirculation loops, or a water heater past its prime (10–12+ years).
Fixes: Tank flush, component replacement, pipe insulation, and recirculation tune-ups. If your heater is aging, a high-efficiency replacement—tankless or hybrid—can cut costs. Our Pasadena Plumbing team can compare options and rebates.

Tankless-specific issues

Error codes and shutoffs: Often due to scale, dirty intake screens, gas supply sizing, or venting problems.
Cold-water sandwich: A brief shot of cold between hot bursts is common without proper recirculation or maintenance.
Solution: Annual descaling is essential in Pasadena. Pershing Plumbing cleans intake filters, verifies gas and vent sizing, and can add buffering tanks or recirculation for steady comfort.

Prevention tips that extend water heater life

Flush your tank: At least once a year—twice is wise in Pasadena’s hard water—to remove sediment and maintain capacity and efficiency.
Check the anode rod: Every 2–3 years (annually if you have a water softener). Replacing the anode is far cheaper than a new tank.
Test the T&P valve: Briefly lift the lever once a year to ensure it moves freely. If it sticks or drips afterward, call our Pasadena Plumbing team to inspect and replace as needed.
Validate expansion tank pressure: The expansion tank’s air charge should match your home’s water pressure (often 50–75 psi). We can test and adjust it.
Set temperature to 120°F: Reduces scald risk and energy use while limiting scale formation.
Insulate hot-water lines: Especially long runs and recirculation loops to cut heat loss.
Maintain tankless units: Annual descaling, cleaning screens, and verifying combustion air and venting are essential in our water conditions.
Consider water treatment: A softener or scale-inhibiting system can dramatically reduce sediment and scale, extending appliance life.

Pasadena-Specific Notes Homeowners Should Know

Hard water is the norm: Expect more scale and sediment. Maintenance matters more here than in softer water regions.
Code and safety: California requires earthquake strapping for storage tanks and often a listed expansion tank on closed systems. Our Pasadena Plumbing team ensures installations meet current codes and permit requirements.
Aging infrastructure: Older gas lines, vents, and flues may need upgrades for safe, efficient operation—especially when switching to tankless or higher-BTU equipment.

When to call Pershing Plumbing

You smell gas, see scorch marks, or the T&P valve is actively discharging
Repeated breaker trips, burner shutdowns, or persistent error codes
Visible tank corrosion or any leak from the tank body
No hot water after basic checks, or temperature swings affecting multiple fixtures
Your heater is 10–12+ years old and repairs are piling up
You want to upgrade to tankless, hybrid heat pump, or add recirculation

Why Homeowners Choose Pershing Plumbing

Local expertise: Our Pasadena Plumbing specialists understand the impact of hard water, older venting, and city code requirements.
Right fix, first time: We stock common parts, perform combustion safety and electrical checks, and back our workmanship.
Options and transparency: Repair when it makes sense, replace when it saves you money. We’ll size the system correctly for your household and explain rebate opportunities.

Your Trusted Pasadena Plumbing Partner

Reliable hot water shouldn’t be a daily worry. Whether you need a fast repair, a maintenance plan to prevent surprises, or a high-efficiency upgrade, Pershing Plumbing is ready to help. Call or message our Pasadena Plumbing team today to diagnose your water heater, restore comfort, and keep it running efficiently for years to come.