Water Heater Repair in San Diego

Most water heater problems come down to one part, not the whole heater. A pilot that won’t stay lit, a burned-out element, a worn relief valve or a failed thermostat can all be replaced, and the heater goes back to work. The exception is a leak from the tank itself, which no repair will stop. Courtesy Plumbing handles water heater repair in San Diego for gas, electric and tankless units, Monday through Friday, 8 AM to 5 PM. We find the cause first and tell you plainly if a repair is worth the money.

Three Checks Before You Call

A few minutes with the heater can save you a service call, or at least tell us what to bring.

• Look at the settings. A dial knocked to vacation or pilot mode, or a tankless unit set to a low temperature, produces lukewarm water with nothing broken. One customer of ours had no hot water because of a setting on the heater, and our technician put it right in a quick visit.
• Check the power or the pilot. On an electric heater, look for a tripped breaker. On a gas heater, look through the sight glass at the bottom for the pilot flame.
• Open the valves all the way. Rheem’s own advice for weak or missing hot water is to confirm the shutoff valves at the heater are fully open.

If you smell gas near the heater, don’t touch anything. Leave the house, then call SDG&E at 1-800-411-7343 or 911 from outside.

What the Symptom Usually Means

No hot water at all

On a gas heater, the usual cause is a pilot that has gone out or won’t stay lit. The part behind it is often the thermocouple, a small sensor that shuts the gas off when it can’t feel the pilot flame. When one customer’s pilot went out on a holiday evening, we were there the next morning, replaced the faulty thermocouple, and the heater they already had kept working. On an electric heater, a tripped breaker, a tripped reset button on the upper thermostat, or a burned-out heating element are the usual suspects.

Hot water runs out too fast

Rheem lists four common causes: sediment taking up room in the tank, a faulty thermostat, a burned-out element, or a damaged dip tube. The dip tube is the pipe that sends incoming cold water to the bottom of the tank. When it breaks, cold water mixes in at the top and the shower turns lukewarm early. If your household has grown, the heater may also simply be too small now. A shower that swings hot and cold only when someone flushes a toilet is a different problem, and it usually sits in the shower valve, not the heater.

Rumbling, popping or whistling

Rumbling and popping come from sediment. San Diego water is hard, about 14 grains per gallon from the City’s plants in 2025. Those minerals settle on the tank floor, and the water heating underneath pops and rumbles on its way up. A high-pitched whistle or screech points to a restriction, such as a valve that’s partly closed or a failing relief valve. Hissing or sizzling is the one to act on right away. Rheem says it can mean water dripping onto the burner or a leaking element gasket, and advises turning the unit off until it’s inspected.

Rusty or smelly hot water

Brown or reddish hot water often means corrosion inside the tank or a worn-out anode rod, the metal rod that corrodes so the tank doesn’t. A rotten-egg smell from the hot side only usually comes from bacteria growing inside the tank. A flush or a new anode rod often clears it up. If the rust keeps coming back, the tank is near the end of its life.

Water around the heater

Where the water starts tells you the most. A drip at a fitting on top, at the drain valve, or from the pipe that runs down from the relief valve is usually repairable. Water coming from the tank body itself means the steel has corroded through, and Rheem is clear that replacement is then the only safe fix. A relief valve that drips again and again may be doing its job. High house pressure or thermal expansion can force it open, and that’s a pressure problem, covered under pressure regulator repair. Never cap or plug that valve. For leaks in general, see water heater leak repair.

What We Can Repair, and What We Can’t

Some problems aren’t in the heater at all. In one home, a roof leak above the water heater closet had flooded the enclosure, and the heater was shaking violently when it fired. We fixed the cause and the owner kept the heater.

When to Stop Repairing

Rheem’s guidance is a fair one to borrow. A standard tank lasts about 8 to 12 years. If yours is under 6 to 8 years old, shows no tank corrosion, and the repair costs well under half the price of a new heater, fix it. If it’s past 10 years and has needed more than one repair lately, or the repair would cost more than half of a replacement, the money is better spent on a new one. Rheem’s repair or replace guide lays out the same rule. The date your heater was made is usually coded into the serial number on its label, so take a photo of that label before you call.

When replacement is the better answer, read about water heater installation for the details of a proper swap. Our La Mesa water heater guide compares tank, tankless and heat pump models. In the City of San Diego a new water heater needs a permit, and we handle that as part of the job.

Tankless Water Heater Repair

A tankless heater fails differently. There’s no tank to leak, but scale from hard water builds up inside the heat exchanger and narrows the passages. Rheem notes that reduced flow is one of the earliest signs of trouble in a tankless unit, and whistling or hissing can come from the same scale. Often the fix is a descaling flush and a cleaned inlet filter, and the unit’s error code helps narrow down anything else. Before one family left town, we diagnosed the trouble with their tankless heater and serviced it in time. Keeping scale out in the first place is covered in our guide on how often a water heater should be serviced.

If your hot water heater is acting up, call (858) 567-0544 during weekday hours. Tell us if it’s gas, electric or tankless, what it’s doing, and the age on the label if you can read it. A picture of the label, uploaded with a Contact Us message, lets the technician arrive with the right part. Our founder, Tony Misleh, has been the company’s master plumber since he started it in 2007, and our state contractor license is CSLB #910268.