Do You Need a Permit for a Tankless Water Heater in Florida?

If you're upgrading to a tankless water heater in Florida, a plumbing permit is required — no exceptions. And depending on whether you choose a gas or electric model, you'll likely need at least one additional permit. The good news: under Florida's House Bill 803 (effective July 1, 2026), most residential water heater replacements now qualify for expedited 5-business-day permit review. Here's what you need to know before your installer starts work.

What Permits Do You Need for a Tankless Water Heater in Florida?

The permit requirements depend on the fuel type:

• Gas tankless water heater: You need a plumbing permit for the water connections and, separately, a gas permit for any gas line work. If the unit requires a new or upsized gas line — which is common when switching from a tank to a tankless unit — the gas permit is mandatory. In many Florida counties, the plumbing and gas permits are pulled as sub-permits under the same project application.
• Electric tankless water heater: You need a plumbing permit for the water connections and an electrical permit for the new dedicated circuit. Electric tankless units typically require one or more 240-volt, 40–60 amp circuits — most homes need a panel upgrade or circuit addition, which triggers the electrical permit requirement.
• Propane tankless water heater: Same as natural gas — a plumbing permit plus a gas permit. If a new LP tank or line is installed, that work must also be permitted.

For a standard tank-to-tank replacement using the same fuel type and existing connections, requirements are simpler. See our full guide on water heater permits in Florida for a comparison.

How Is a Tankless Water Heater Permit Different From a Standard Water Heater Permit?

Switching from a storage tank to a tankless unit involves more than swapping appliances — it often means upgrading your home's infrastructure. Here's what makes the permit more involved:

• Gas line capacity: A gas tankless unit typically demands 150,000–200,000 BTU per hour at full capacity — roughly four to five times the demand of a conventional tank heater. Existing gas lines are almost always undersized and must be upgraded to meet this demand. The gas permit covers the inspection of that upgrade.
• Venting: A tankless gas unit requires direct-vent or power-vent technology. Existing B-vent flues from a tank water heater cannot be reused. The new venting system — which routes combustion gases directly outside through the wall — must meet Florida Building Code requirements and pass inspection.
• Condensate drain: High-efficiency condensing tankless units (with AFUE ratings above 90%) produce acidic condensate that must be properly drained. The permit application must address how condensate disposal is handled.
• Electrical: Even gas tankless units require a dedicated 120-volt outlet for the electronic ignition and controls. If that outlet doesn't exist near the installation location, an electrical permit may also be needed.

Because of these additional requirements, a tankless conversion takes longer to inspect than a standard water heater swap — plan for at least one rough-in inspection and a final inspection.

How Much Does a Tankless Water Heater Permit Cost in Florida?

Permit fees for tankless water heater installations in Florida vary by county but typically fall in these ranges:

• Plumbing permit: $75–$200 in most Florida counties
• Gas permit (if gas line work is required): $75–$175
• Electrical permit (if new circuit or panel work is required): $75–$200

For a gas tankless conversion that requires gas line upsizing and new venting, expect to pay $150–$400 in total permit fees across all sub-permits. Electric conversions requiring a new circuit land in a similar range. These permit fees are separate from the cost of engineering, materials, and installation labor. For a statewide look at permit costs by project type, see our Florida building permit cost guide.

Does the HB 803 Expedited Review Apply to Tankless Water Heater Permits?

Yes. Under House Bill 803 (effective July 1, 2026), Florida local governments must review permit applications for residential improvements valued under $15,000 within 5 business days. Most tankless water heater installations fall under this threshold, which means:

• The plumbing permit, gas permit, and electrical permit must each be reviewed within 5 business days of a complete application being submitted
• If the building department misses its deadline, the permit is automatically deemed issued by operation of law — you don't have to wait indefinitely for a decision
• If your contractor uses a licensed private provider to perform the plans review, the county has only 10 business days to issue the permit — useful for more complex installations

In practice, simple water heater permits in Florida were already being processed quickly before HB 803. The new law adds a legal backstop that prevents delays on routine jobs. For a county-by-county look at how permit timelines work under the new rules, see our Florida building permit timeline guide.

Who Can Install a Tankless Water Heater in Florida?

Florida law requires that water heater installations be performed by a licensed plumbing contractor. Gas line work must be done by a plumber licensed for gas work or a licensed gas contractor. Electrical work — new circuits, panel modifications — must be performed by a licensed electrical contractor.

Florida's owner-builder exemption allows homeowners to pull permits for their own primary residence, but it does not allow homeowners to perform plumbing, gas, or electrical work themselves unless they hold the appropriate trade license. In practice, most homeowners hiring a plumber for a tankless conversion allow the plumber's company to pull the permit as part of the job — this is standard and the most straightforward path to a properly permitted installation.

What Inspections Are Required for a Tankless Water Heater?

Inspection requirements vary by county and scope of work, but a typical tankless water heater installation in Florida involves:

• Rough-in inspection: Before the unit is connected and walls are closed, the inspector verifies that gas line sizing, venting rough-in, and electrical rough-in all meet code. This is the most critical inspection — any deficiencies must be corrected before the work is covered.
• Final inspection: After the unit is fully installed and operational, the inspector confirms that the installation matches the permitted scope, venting is properly terminated, gas connections are leak-free, and the unit is functioning correctly.

Your plumber will schedule inspections through the county's building department portal. In most Florida counties, inspections are available 1–3 business days after request. For a full walkthrough of how permit inspections work in Florida, see our Florida permit inspection guide.

What Happens If You Install a Tankless Water Heater Without a Permit?

Skipping the permit on a tankless water heater installation in Florida creates several serious problems. An uninspected gas installation carries fire and carbon monoxide risks that an inspected installation is specifically designed to prevent. Unpermitted work can void your homeowner's insurance coverage for related damage claims. And when you sell your home, a buyer's four-point inspection will flag the unpermitted water heater — lenders may require it to be legalized or replaced before they'll fund the mortgage.

After-the-fact permits are available in most Florida counties but typically cost double the normal fee and require the same inspections — including opening walls if the rough-in work is already covered. You pay the same amount in permit fees while adding significant hassle. For a full breakdown of the risks and remedies, see our guide on what happens if you build without a permit in Florida.

Skip the headache — tell us about your project and we'll match you with a licensed plumber in your county who handles the permit from start to finish.