TANKLESS WATER HEATER INSTALLATION IN ST. PETERSBURG, FL

For all your flows, trust the Pros · St. Petersburg & Tampa Bay

A tankless water heater gives your St. Petersburg home endless on-demand hot water in a wall-mounted unit a fraction the size of a tank — but only when it's sized, vented, and installed correctly. Flow Pros Plumbing installs, replaces, repairs, and descales tankless systems across St. Pete, from Old Northeast and Kenwood to Snell Isle and Shore Acres. We're factory certified by both Navien and Rinnai, the two leading tankless brands. Call 727-265-9639.

Is a Tankless Water Heater Worth It in St. Petersburg?

For most St. Pete homes, yes — a tankless unit pays back through a longer lifespan, lower energy use, and endless hot water. It heats water only as you use it, so there's no tank reheating water around the clock. The trade-off is a higher upfront cost and, often, gas or venting upgrades at install.

• Endless hot water on demand for back-to-back showers, dishes, and laundry.
• 20+ year lifespan — roughly double a tank heater's 8 to 12 years.
• Compact, wall-mounted design that frees up closet or garage space.
• Lower energy use by eliminating the standby heat loss of a stored tank.

If you're still weighing tank against tankless, our water heater repair & replacement page lays the two side by side.

Navien vs. Rinnai: Which Tankless Brand Is Right for You?

Navien and Rinnai are the two most trusted tankless brands, and because Flow Pros is certified in both, we recommend the right fit for your home instead of pushing one line. Both are excellent; the choice comes down to your gas supply, venting, and features.

As certified installers for both, we register your manufacturer warranty correctly and service either brand — so you're never stuck finding someone who knows your unit.

Sizing a Tankless Unit: Will It Keep Up?

A tankless heater is sized by flow rate — gallons per minute (GPM) — not by tank capacity. The unit has to deliver enough hot water for every fixture you'd run at once, so sizing is where most botched installs go wrong. Florida has an advantage here: warm incoming groundwater means the heater needs less temperature rise, so units deliver closer to their peak GPM than they would up north.

• A shower uses roughly 1.5–2.5 GPM.
• A kitchen or bathroom faucet uses about 1–1.5 GPM.
• A dishwasher or washing machine uses about 1–2 GPM.

We add up your realistic peak demand — say, two showers and a sink at once — and size the unit to match, so you never run cold mid-shower.

Gas Line, Venting & Why Certified Installation Matters

Tankless units fire at a much higher BTU rate than tank heaters, so they often need an upsized gas line and dedicated stainless or PVC venting. Getting this wrong is the most common reason a tankless underperforms or fails early. There are two efficiency classes to know.

Certified installation means we calculate gas load, size the venting, and set up the unit so it hits its rated efficiency and keeps its warranty — a miscalibrated install voids both.

Tankless Maintenance: Descaling in Hard-Water St. Pete

Tankless units need annual descaling, and in St. Petersburg's hard water that's not optional. Mineral scale builds up on the heat exchanger, drops efficiency, and can void your warranty if it's neglected. We flush and descale the system to keep it running at full output.

Pairing your tankless unit with a water softener dramatically slows scale buildup and extends the heat exchanger's life — a smart combination in our hard-water region. Ask about a yearly maintenance visit when we install.

Tankless Cost, Rebates & Financing

A tankless system costs more upfront than a tank heater, mainly because of the unit itself plus any gas and venting upgrades. We quote the full job before starting, and financing is available to spread the cost. One honest note on incentives:

Water heating is about 18% of a typical home's energy use, so the efficiency gain from a right-sized tankless unit shows up on every bill.

Tankless Water Heater FAQs