Replacing a Solar Inverter in Florida

The inverter page is about what the box does. This one is about the week it dies. The panels are usually fine. The house is suddenly buying all of its power again, and the quote you get depends on which of three jobs someone is actually proposing.

Make sure it is the inverter

A flat line in the app is not a diagnosis. Check the obvious things before you pay for a truck.

• The solar breaker in the main panel is on. So is any switch on the inverter itself.
• The utility is up. A grid-tied inverter is required to stop when the grid stops. If the neighbor is dark too, wait.
• The monitoring gateway has power and a network connection. A dead Wi-Fi stick looks exactly like a dead array until you look at the meter.
• On a microinverter or optimizer system, one panel at zero and the rest normal is that panel’s device, or a connector, not the whole system.

If the breaker is on, the grid is up, and a sunny afternoon still shows nothing, then it is fair to treat the string inverter as the failed part until a technician proves otherwise. Do not open the cover. The maintenance page is the habit that catches this in days instead of a season. Start the warranty claim the same week. A string inverter that is down in July is not a winter project.

Three jobs that get quoted as one

Job one is a wall swap. The string inverter on the garage wall is dead. The new unit fits the same wires, the roof is not opened, and the panel count does not change. This is the repair people picture. It is also the one that disappears when the old model is discontinued and the new model will not accept the voltage of the existing strings. The person doing the work has to check that, not guess. Strings were built for the old inverter’s window. A new box with a different window can be the wrong box even if the watt rating looks right.

Job two is one device on the roof. A single microinverter, or a single optimizer, has failed. One panel comes off, the device is swapped, the panel goes back, and the monitoring has to see the new serial number. The rest of the array can keep running. The bill is labor and access. A one-story shingle roof is not a two-story tile roof.

Job three is a redesign. The quote replaces the string inverter and adds a box under every panel, or it throws the string inverter away and puts a microinverter on every panel, or it swaps in a hybrid inverter because someone now wants a battery. That is new wiring, a permit, and usually a conversation with the utility. It can be the right job. It is not the same job as putting a new box on the wall. If one quote is $2,000 and another is $8,000, ask which of the three is on the paper. You may be comparing a repair to a rebuild.

What the equipment costs, and what labor costs

There is no Florida price list for this, and there is no official survey of Central Florida invoices. What exists are published 2026 national ranges. Use them to recognize a wild quote. Then get two written local quotes that name the model.

A residential string inverter, as equipment, is often about $800 to $2,500. A published all-in figure for replacing one, parts and the labor to hang it, land the wires, and commission it, commonly sits around $1,500 to $3,500 for a normal house-size unit. The high end is a larger unit, a hybrid-style inverter, a tight location, or a long commissioning. The low end is a straightforward swap on an open wall. A discontinued model can push you off the low end because the compatible replacement is not the cheapest unit on the shelf.

A microinverter, as a part, is often about $150 to $350. Replacing one is not a $150 job once someone is on the roof. Published all-in figures for a single unit are often a few hundred dollars, and they climb when several units from the same era fail together, or when the roof is tile, steep, or two stories. Twenty new microinverters, as a retrofit of a whole array, are a few thousand dollars of hardware before the labor of a full roof day. That is job three.

An optimizer retrofit is the same shape. The small boxes are the hardware on the roof. A new string inverter may still be required if the old one cannot run them. Ask the quote to split roof hardware, the wall unit, and labor. A single number cannot be compared to a wall swap.

A hybrid inverter, the kind that can charge a battery, is often about $1,000 to $5,000 for the inverter alone, and that range is so wide it is almost useless without a model. The battery is the large check. A home battery in the 10 to 14 kilowatt-hour class is a separate project, covered on the battery page. Do not let an inverter quote quietly become a storage quote.

Labor is the line that moves. A wall box in a garage with the breaker beside it is an electrician’s half day or less. A microinverter under a panel means the panel comes off, the new device is torqued to the manufacturer’s spec, the connectors are seated, and the monitoring is paired. On tile, panels do not slide. Broken tiles are a real extra. If the crew has to remove a row of panels to reach one device, you are paying for that row.

Permit fees, if the county charges one, are small next to a roof retrofit and are not included in the national equipment ranges. Ask the quote whether the fee is in the number. The same for a lift, a second trip for inspection, and the time to file with the utility.

What the warranty pays, and what it does not

A manufacturer warranty usually covers a defect in the part. It does not automatically cover the truck, the roof, the permit, or the hour spent on the phone with the utility. Read the warranty for your serial number. The term on the sticker is not the whole document.

Enphase’s limited warranty for covered IQ microinverters in the United States, the version effective May 2, 2026, is 25 years from activation for the listed IQ8 and IQ9 models. The same document says the warranty does not include the cost of labor to un-install the covered product, to re-install a replacement, or to troubleshoot the owner’s electrical system. If the installer who registered the system is gone, Enphase can still be the place the part comes from. The person on the roof is a separate hire. Register the system in your name so the claim is not trapped in a closed company’s portal. The installer-gone page is the rest of that problem.

String-inverter warranties are commonly about 10 to 12 years, sometimes with a paid extension. SolarEdge’s power optimizers are commonly warranted for 25 years, and the SolarEdge inverter beside them is commonly 12 years, with a longer term available on some models for a fee. Those are published terms, not a promise about the unit on your wall. Look up the serial number. A unit that failed at year eleven, on a ten-year warranty, is a cash job. A unit that failed at year six is a warranty job plus whatever labor the document excludes.

Shipping a replacement is not the same as installing it. Ask, in the claim, whether they pay labor, and get the answer in the claim email. A phone promise does not survive a change of representative.

The permit is a local answer

Florida does not publish one rule that says every inverter swap needs a building permit, or that none of them do. The building department in the city or county where the house sits makes that call, and two neighboring cities can answer differently.

The useful distinction is repair versus redesign. Putting a similar inverter back on the same wall, on the same circuits, to keep the existing system working, is the kind of work many departments treat as a repair. Changing the roof wiring, adding a device under every panel, adding a battery, moving the inverter, or increasing the number of panels is new electrical work. That needs a permit, drawings, and a final inspection under the code edition that department is using today.

Rapid shutdown is the piece that changes the price. Older rooftop systems, especially those permitted before the later editions of the National Electrical Code, often do not have a device under each panel. They were legal when they were built. The code does not reach back and rebuild them on the day a part fails. If the department decides your scope is large enough to be an alteration, the current rapid-shutdown rules can apply to the work, and sometimes to the array the work touches. That can mean shutdown devices or optimizers under panels that were not in the original “just replace the box” plan. Ask the building department, before anyone orders equipment, which of these your scope is. An email is better than a guess from the salesperson.

The person who pulls the permit needs a license that covers the work. A Florida certified electrical contractor or a certified solar contractor is the usual path. Confirm the license with the Department of Business and Professional Regulation. This is not a weekend project on a system tied to the utility. The DIY page covers the line between what a homeowner can do and what has to be licensed.

The utility is a second office

The building permit is not permission to operate in parallel with the grid. That permission came from the utility when the system was first approved. A replacement does not always reopen it. It does in specific cases.

For investor-owned utilities, including Duke Energy Florida and FPL, Florida Administrative Code Rule 25-6.065 is the rule. It has been in effect since April 7, 2008. For an inverter-based system, the gross power rating used in that rule is not the number printed on the inverter. It is the total installed DC nameplate of the panels, multiplied by 0.85. If you modify the system in order to increase that gross power rating, you must submit a new application at least 30 days before the modification. FPL’s own interconnection agreement says the same thing, and it also requires a new application if you add another generating system. Adding panels can be that trigger. Replacing an inverter and leaving the panels alone does not, by itself, increase the DC nameplate, so it does not by itself trip that 30-day rule.

That is not permission to install a mystery box in silence. The same rule requires a utility-interactive inverter, or another certified device, that stops sending power when the grid goes down. Duke has required inverters certified to UL 1741 SB, the test tied to the newer IEEE 1547-2018 grid-support standard, on new interconnections since January 1, 2024. A replacement that becomes a new application has to be a model that utility will accept now, not a used inverter from another state and not a gray-market unit. OUC is not under the PSC rule. OUC’s interconnection requirements say the customer must submit a new application at least 30 days before any change to the gross power rating, and that the inverter must be listed to UL 1741. OUC’s document treats a utility-interactive inverter that passes that listing as complying with IEEE 1547-2018. Read the current OUC sheet before you rely on a memory of it. Municipal utilities write their own.

What to do, in order. If the new unit is the same model, or the manufacturer’s listed successor, and the panels are unchanged, call the utility and ask whether they want the model updated on the existing agreement. Do not assume they do. Do not assume they do not. If the AC rating changes, the model is unrelated, panels are added, or a battery is added, file before the work. FPL’s learning center tells installers that equipment changes need another net-metering application 30 days prior. Turning a redesigned system on because the old permission is still in a drawer is how a homeowner ends up producing power the utility has not accepted.

You can file this yourself if the original company is closed. The portals are Duke Energy Florida, FPL, or OUC, depending on the logo on the bill. You will want the one-line diagram, the new inverter’s spec sheet, and the old agreement if you still have it. A new contractor can file it if that is in the quote. Say so. “We’ll handle the utility” is meaningless unless the quote names the application.

The export rate does not change because you replaced a box. It changes if the utility treats the work as a new system and your tariff has moved, which is the OUC question on the Duke, FPL, and OUC page. Ask that question before a “while we are up there” expansion of the panel count. A repair should not accidentally become a new interconnection on worse export terms.

What a normal wall-swap week looks like

1. You, or the company, confirm the failure and open the warranty claim with the serial number and a photo of the error.
2. The replacement model is checked against the string voltage and against the utility’s accepted equipment, if the utility wants that check.
3. You ask the building department if this scope needs a permit. If it does, nobody hangs the box until the permit is in hand.
4. The inverter arrives. Back-ordered string inverters happen. Ask for a date, not “soon.”
5. The crew kills the AC breaker, confirms the DC side is safe, swaps the box, and commissions it. Monitoring is moved to your email if it was still in the old installer’s.
6. If there was a permit, the inspector closes it. If the utility required an application, you do not treat the system as approved until they say so.

A roof job adds a weather day and, on tile, a risk of broken tiles that should be in the quote as a unit price, not a surprise. A redesign adds design time, the permit review, and the utility’s clock. The 30-day notice is a minimum in the rule. It is not a promise that the portal answers in 30 days.

When to repair, when to redesign, when to wait

Repair the wall unit if the roof is simple, the strings are compatible with a current listed inverter, the warranty or a straightforward cash price will do it, and you do not have a battery plan. You will likely do this once in the life of the panels. Paying for a full roof of microinverters because one box died, on an unshaded south roof, is a different project. It can be justified. It should be chosen, not bundled.

Redesign if the department requires rapid shutdown you do not have, if the old strings cannot feed any inverter you can still buy, if shade or several roof faces have been wasting the string design for years, or if you are adding a battery and the old inverter cannot run one. Get that scope in writing, with the permit and the utility filing included.

Wait only if the system is still producing and someone is selling you a replacement on age alone. A string inverter at year nine, still online, with a year of warranty left, does not need a preemptive swap. A string inverter at year nine that is already throwing errors in August is not a unit to nurse through another summer. The lost production is the expensive part, and it does not show up on the contractor’s invoice.

If you are buying the house, the age and the warranty end date belong on the closing checklist. A dead inverter, or one that will be out of warranty next year, is a dollar figure in the offer, not a pleasant surprise after the first full electric bill.

What to require on the quote

• Which of the three jobs this is, in one sentence.
• The new model, and a statement that it fits the existing string voltage, or a description of the roof work if it does not.
• Equipment, labor, permit fee, inspection trip, tile breakage, and utility filing, as separate lines.
• Whether a warranty part is being used, and who pays labor.
• Whether the building department has been asked if the scope needs a permit.
• Whether the utility has to be notified, and who files.
• The date monitoring will show production in an account you control.
• What the system will and will not do in an outage after the work. A new string inverter still shuts off when the grid does.

Two quotes that describe the same job are comparable. Two quotes that describe different jobs are not. The panels can wait. The inverter is the part that stops the whole investment until someone hangs a working one.

This page is general information, not electrical, code, or utility advice. Your building department and your utility control the job on your house. Prices are published national ranges, not a bid.