A tankless unit has no tank to rust through, so a leak almost always comes from a part that can be fixed. Here is where tankless leaks start, what to do first, and what the repair usually costs.
Call (813) 688-9792 — Open 24/7Three steps before the technician arrives.
First, close the hot and cold isolation valves on the unit. Tankless heaters have service valves for exactly this reason, and closing them stops the leak without shutting off water to the whole house. Second, cut the power: unplug the unit or flip its breaker, and turn the gas valve off on a gas model. Third, put a bucket under the drip and dry the area. Tankless units are often mounted in garages, closets, and laundry rooms in Valrico and Brandon homes, and even a slow drip can reach flooring, drywall, and the unit's own electronics. If water is spraying, pooling fast, or near the control board, call right away at (813) 688-9792. We answer around the clock.
No tank means the leak is almost always a part, not the whole unit.
The most common tankless leak. The hot and cold connections under the unit use seals and unions that wear out, loosen with vibration, or corrode. A drip that falls from a connection point is usually a fitting fix, and it is one of the cheaper repairs.
Scale buildup makes the exchanger run hot in one spot. Over time that stress can open a pinhole leak inside the unit. Water then drips from the bottom of the casing even though every fitting looks dry. Exchangers can be replaced, and many are covered by long manufacturer warranties.
A relief valve that drips or will not reseat is doing its job or wearing out. High incoming water pressure makes it worse. The valve itself is a small part. The real fix includes checking your home's water pressure so the new valve does not drip too.
High-efficiency condensing units produce acidic condensate that drains through a small line. A cracked or clogged condensate line leaks water that looks like a unit failure but is a minor repair. This is common on newer Brandon installs.
Tankless units are built to be repaired, part by part.
Unlike a tank heater, a tankless unit rarely needs full replacement over a leak. Fittings, valves, seals, flow sensors, and igniters are all replaceable, and a well-kept tankless heater lasts 15 to 20 years. Repair is the right call in most cases. Replacement enters the picture when the heat exchanger has cracked on a unit that is out of warranty and over 12 to 15 years old, or when a unit has needed repeat repairs in a short span. We give upfront pricing before any work starts and tell you honestly which side your unit falls on. Minor fitting and valve repairs are usually a few hundred dollars. Exchanger work costs more and depends on the brand. If replacement is the smarter move, see our water heater replacement guide for tank versus tankless options.
Hard water is the number one tankless killer in this area.
Valrico and Brandon water comes from the Floridan Aquifer and carries heavy calcium and lime. Inside a tankless heat exchanger, those minerals bake onto narrow water passages as scale. Scale makes the unit run hotter, stresses seals and joints, and is behind most leaks, error codes, and lukewarm-water complaints we see locally. The fix is simple and cheap: a descaling flush once a year. Skipping it is the main reason tankless units here fail years before they should. If your unit has never been descaled and is over two years old, it is overdue. A flush plus a fitting and seal check catches most leaks before they start.
Also serving Valrico, Brandon, Riverview, and Bloomingdale.
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