Water that collects around a tank water heater comes from one of four places: a loose fitting, a leaking drain valve, the relief valve, or a hole in the tank itself. The first three can often be repaired. A leaking tank cannot, and the unit has to be replaced. The wider picture, covering tankless water heaters as well as water heater installation, is on our water heaters page.
First, close the valve on the cold pipe feeding the heater. Then kill the breaker, or turn the gas dial to off, and slide a bucket under the drip. Local plumbing businesses reach Santa Ana homes through our service, so if the leak is bigger than a drip, call us on the number above and get the visit booked while you deal with the water.
Which part of the heater is the water coming out of?
Read the pattern of the wet. Wetness at the top usually means a loose cold or hot pipe connection. Water at the side, running down from a short pipe with a lever, points to the relief valve. A drip at the bottom may be the drain valve, or the tank itself. Wipe everything dry and watch for ten minutes to see where the first bead forms.
A flashlight and a dry paper towel do most of the diagnosis. Press the towel against each fitting in turn. Pay attention to the metal flex connectors, the brass nipples on top, the drain spigot near the floor, and the thin discharge pipe that runs from the relief valve down toward the floor or outside.
One thing that looks like a leak but is not: condensation. A gas heater in a cool garage can sweat on its lower casing during a busy morning of showers. If the wetness stops when the water has been off for an hour, you are looking at moisture from the air, not the tank.
Can a leaking hot water tank be repaired?
Fittings, valves and connectors can be repaired. A tank whose steel shell has rusted through cannot, because the leak is in the vessel that holds the pressure. Plumbers do not weld or patch these. The repair is a replacement heater, so judge by the spot the water leaves from and the age of the unit.
Signs the shell is gone: water seeping from the seam between the jacket and the base, a rusty weep along the bottom, or puddles that return after you have tightened every fitting. Hot taps that run rust-coloured point the same way. For the repair-or-replace call, our piece on water heater lifespan helps, and the cost of the second route is in water heater replacement cost.
Santa Ana's water is hard, around 15 grains per gallon by the City's own figures, and scale builds on the tank floor and heating parts over the years. Sediment cooks the steel floor of a tank, so an older heater in a house that has never had it flushed is usually closer to replacement than a newer one.
What causes a relief valve or drain valve to drip, and how is it fixed?
A dripping relief valve is either doing its job because the tank pressure is too high, or it has worn out. Check your house pressure and look for a thermal expansion tank first. If those are fine, the valve itself needs replacing. A dripping drain valve can sometimes be closed snugly by hand, otherwise it is swapped.
Hot water expands as it heats. When the house has a pressure regulator or check valve, the added water cannot back up into the street main, so pressure climbs until the relief valve opens. A small expansion tank on the cold line absorbs it, and we cover that in expansion tank replacement.
Replacing a relief valve means draining part of the tank and working with scalding water, and the discharge line must be run to code. Never plug the valve outlet. That defeats the one job the valve has. Details of the swap are in pressure relief valve replacement.
A plumber tests a valve by flicking its lever with a pail beneath the outlet. Water should rush out, then stop crisply. If it dribbles afterwards, it is worn.
Is a tankless water heater any different when it leaks?
Tankless units hold almost no water, so a leak usually comes from a connection, the condensate line on a high-efficiency gas model, or a failing heat exchanger. Isolate it the same way as a tank: water first, then electricity or gas. Repairs on tankless heaters go to a plumber, since they involve venting and sealed gas parts.
A tankless unit that pools water at the bottom may be draining condensation, which is normal if it runs to a drain. A steady leak from the casing is not normal, and the heater should be switched off. Brand makes little difference to where leaks start. Rheem, Whirlpool and Bosch units all have supply fittings, a relief valve or drain, and a rating plate printed with the model and serial codes, and that is what any plumber asks for first.
If you are weighing a replacement, tank versus tankless sets out the trade-offs for Orange County homes.
What if I have no hot water as well as a leak?
If the heater is leaking and the water is cold, switch the heater off and leave it off. A gas heater with a leak should not be relit, and an electric element that has lost its water can burn out in seconds. Cold water alone, with no leak, is covered by checking the pilot, the breaker and the thermostat.
For a gas model, look at the pilot or the electronic igniter light and at the gas control dial. An electric unit has a breaker and a red reset button beneath the upper thermostat cover, so check both. If any of those restore heat, great. If the breaker trips again or you smell gas, stop. In that case step outside and phone SoCalGas on 1-800-427-2200. When anyone is in immediate danger, 911 comes first.
More on faults without a leak: why there is no hot water in my house, and whether it counts as an emergency in no hot water, urgent or not.
How much will fixing or swapping the heater run?
Published 2026 national cost guides put a typical installed tank replacement between roughly $900 and $2,500, with a relief valve or fitting repair costing far less. The permit, haul-away, new straps and an expansion tank, which can add about $125 to $300 on their own, change the final number.
Take these as ballpark figures only. Your own quote itemises the unit, labor, permit and code items. Tank size, gas or electric, how tight the closet is, and any vent changes all move the total.
In Santa Ana the City's Permits Counter names water heater replacement among the jobs needing a permit, and California law has every residential heater braced or strapped against shaking. Both are part of a proper replacement, and the process is explained in water heater permits.
Common questions
What are the signs of a worn-out relief valve?
A bad relief valve leaks steadily from its discharge pipe, will not stop dripping after the lever is lifted, or shows mineral crust at its outlet. If the house pressure and expansion tank are in order and the valve still drips, it is worn. Because it is a safety device, have it replaced.
Can I repair a water heater leak myself?
You can tighten a loose connection, close a drain valve or reseat a flex connector if the heater is off and cold. Gas piping, relief valve replacement and permit work should go to a plumber, and a leaking tank body needs replacing, not patching. Whichever way it goes, shut the water off first.
Is solar hot water heater repair different?
Solar systems add roof collectors, pumps and controllers to a storage tank, so leaks can sit on the roof or in the loop piping as well as at the tank. The storage tank rules above still apply. Roof and loop work is a specialist call, so ask any plumber about solar experience before booking.
Does a leaking heater need a same-day visit?
A slow weep can usually wait for a booked appointment once the supply is closed and a bucket sits underneath. A steady stream, a spreading rusty puddle or a gas smell needs a same-day call. Water running into walls or a ceiling below should be treated as urgent.
For the wider picture, start with the plumber guide for Santa Ana.
Sources
- Wikipedia, Water heater (temperature and pressure relief valve, expansion tank)
- California Health and Safety Code section 19211, water heater bracing
- City of Santa Ana, Permits Counter
- SoCalGas, safety and prevention
- Cost guides for water heater repair and replacement, 2026 (national figures, read November 2026)
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