When the Hot Water Stops or the Tank Starts to Leak
A water heater that quits is one of the most common reasons customers call. South Fullerton Plumbing repairs and replaces gas and electric tank water heaters and tankless units in Fullerton homes, condos and rental properties. The first step is finding out whether the problem is a part, such as a thermostat, element or gas control, or the tank itself.
Warning Signs
- Rusty or discolored hot water while the cold water runs clear
- Rumbling, popping or knocking from the tank as it heats
- Water or rust at the base of the tank, or a damp drain pan
- No hot water, or hot water that runs out much sooner than it used to
- A pilot that will not stay lit, or a burner that lights and goes out
- Water dripping from the temperature and pressure relief valve discharge pipe
Hard Water and Scale in Orange County
Water across much of Orange County is hard, and the minerals settle as scale in a tank and inside the heat exchanger of a tankless unit. In a tank, scale insulates the bottom from the burner, which wastes fuel and produces the familiar rumble. In a tankless heater, it narrows the passages and can trigger error codes. Flushing a tank and descaling a tankless unit on a regular schedule slows that buildup and extends the life of the equipment.
Strapping and Relief Valve Requirements in California
California requires every water heater to be braced with seismic straps against movement in an earthquake, and every tank to carry a working temperature and pressure relief valve with a discharge pipe that runs to an approved location. Gas units also need correct venting and combustion air. A replacement is the time to bring all of this up to the current California Plumbing Code, and a permit from the City of Fullerton Building and Safety Division is normally part of the work.
Tank or Tankless, and What Size
Both designs heat water well. The choice depends on the space available, the gas line and venting already in place, and how the household uses hot water at the busiest time of day.
More columns to the right: swipe.
| Type | Upfront complexity | Space needed | Hot water supply | Lifespan range | Fuel and venting needs |
|---|---|---|---|---|---|
| Tank | Lower: a like-for-like swap usually reuses the existing connections and venting | A floor footprint of roughly two feet across, in a garage, closet or utility room | A stored volume; once it is used, recovery takes time | Commonly 8–12 years | Gas units need a flue and combustion air; electric units need a dedicated circuit |
| Tankless | Higher: often a larger gas line, new venting and a new electrical outlet | A wall-mounted unit about the size of a suitcase | Continuous, limited by flow rate (gallons per minute) | Commonly 15–20 years with regular descaling | Gas units need sealed venting sized to the unit and enough gas supply at full fire |
Sizing Guide
The guide below gives a starting range from household size, bathrooms and how many fixtures run at once. It is a general guide; the final size also depends on the gas supply, venting and the fixtures in the house.
Water Heater Sizing Guide
Choose the household details above and press Show Sizing.
The sizing guide needs JavaScript. As a rough rule, 40 to 50 gallons suits three or four people, and a tankless unit needs about 2 to 2.5 gallons per minute for each shower running at once.
Repair Work
- Thermostats, heating elements, thermocouples and gas control valves
- Temperature and pressure relief valves and their discharge piping
- Supply connections, shutoff valves and expansion tanks
- Flushing tanks and descaling tankless heat exchangers
- Seismic strapping brought up to current requirements
Repair Versus Replacement
Should an older water heater be repaired or replaced?
A failed thermostat, element, thermocouple or gas valve on a sound tank is usually worth repairing. A tank that leaks from its body cannot be repaired: the lining has failed. Age matters too; a tank near the end of its usual range that needs a costly part is often better replaced, while a younger unit with a single failed part is usually repaired. The decision is explained once the cause is known.
How long does a replacement take?
A like-for-like tank replacement is commonly completed in a single visit. A change from tank to tankless takes longer because the gas line, venting and electrical work change, and a permit and inspection are part of it.
Why does the water heater rumble or pop?
Sediment and scale collect at the bottom of the tank, and the burner heats water trapped under that layer. The sound is the water boiling through it. Flushing reduces it; a heavily scaled tank may not recover.
What should be done if the tank is leaking now?
Turn off the cold supply valve above the heater, turn the gas control to Off or switch off the breaker, and keep belongings away from the water. The Emergency Plumbing page lists the first steps in order.
To arrange a water heater repair or replacement, book an appointment or call (909) 572-8236. The make, the age on the rating label and a photo of the connections are useful to send ahead.