The Complete Guide To Delta Solivia Inverter Error Codes

Why a Delta Solivia error code is worth sorting now

A Delta Solivia showing an error has usually stopped feeding your home, and every sunny day it stays that way is power bought back from the grid at full price. The red Earth Fault light deserves the most attention: an isolation warning means live DC is leaking to earth somewhere, usually through water in a panel, isolator or connector on the roof.

Delta has left the Australian residential market. The Solivia and RPI inverters still on roofs here went in between about 2010 and 2017, and while they were solid units, the fleet is ageing and support is limited. Parts are hard to come by, so most serious faults inside a Delta end in a replacement. The panels usually stay, and a hybrid inverter can make room for a battery at the same time. Plenty of Delta faults are still simple: a tripped switch, a wet connector or the grid itself.

Caught early, a roof-side fault is a repair and you keep producing while you plan what comes next. Left alone, a warning becomes a shutdown: the Solivia's isolation warnings let it keep running, but Error # 506 and 508 stop it altogether.

Find your code in the table below to see what it means and how urgent it is. If your home is in Adelaide, the Adelaide Hills, Gawler, the Barossa, the Fleurieu, Murray Bridge and Yorke Peninsula in South Australia, or North Brisbane, Caboolture, Bribie Island, the Sunshine Coast, Noosa and Gympie in Queensland, our own licensed electricians will go through it with you over the phone for free before anyone drives out. Check your postcode to see if we cover you.

Which Delta Solivia inverter do you have?

The model is on the label on the side of the inverter. Delta sold two ranges here, and they show faults differently.

Solivia (for example SOLIVIA 3.0 AP G3 TR): string inverters that show faults in words or as Error # numbers, with a red Earth Fault light. Installed here from about 2010 to 2017. Delta has left the market, so a serious fault usually means a replacement.
RPI H3A and H5A: the RPI range, which shows short E and F codes such as E34 or F24, marked (RPI) in the table. Same era and the same replacement position.

All 29 Delta Solivia error codes, explained

A Solivia names its fault on the display, like AC voltage failure or Isolation start-up warning, or shows Error # and a number. The RPI range shows a short E or F code instead, and those rows carry (RPI) in their title. Every code is below, grouped by what it relates to: the grid and mains supply, the panel input and power output, insulation and earth faults, heat and cooling fans, and the unit's internal hardware. The number in brackets after each code's name is its source in the reference list.

Stop and call A safety or hardware fault that nobody can fix from a phone. Do the one safe restart at most, then call.
Worth a look Something to check or restart safely. If it comes back, book a visit.
Wait and watch The inverter has paused for a reason outside itself, usually the grid or the light, and restarts on its own.

We always err on the cautious side: when a code sits between two ratings, it gets the higher one.

Grid and mains supply error codes 8 codes

The mains grid coming into the unit: voltage, frequency and outages. Many of these are the grid, not the inverter, and clear on their own. 2 stop and call, 6 wait and watch.

Error code	What it means	What to do
AC frequency failureDelta Solivia AC frequency failure	Grid frequency outside limits^[1] The frequency of the mains supply is outside the range the inverter is allowed to feed into, so it has disconnected. It is a network event and the inverter reconnects by itself when the grid settles. Safe steps in the lookup	Wait and watch
AC voltage failureDelta Solivia AC voltage failure	Grid voltage outside limits or missing^[3] The mains voltage at the inverter is outside its limits or missing altogether. During a blackout that is normal. Otherwise the solar supply breaker has tripped, or the voltage at your house is running high in the afternoons. Delta says if the screen reads about 0 V the problem is on the AC side, and about 240 V with this message means the inverter itself is faulty. Safe steps in the lookup	Wait and watch
DC injection failureDelta Solivia DC injection failure	DC in the grid current^[4] The inverter is putting too much DC into the current it sends to the grid. Delta Australia says this was fixed by a firmware update on Solivia units with a service kit, and otherwise the unit is replaced. Try a restart once; if it comes back it needs a service visit. DC on the AC side is a protection fault, so we treat it as a call. Safe steps in the lookup	Stop and call
E01Delta Solivia E01	Grid frequency high (RPI)^[2] On the RPI range: the mains frequency is above the allowed limit, so the inverter has disconnected. A network event; it reconnects by itself. Safe steps in the lookup	Wait and watch
E02Delta Solivia E02	Grid frequency low (RPI)^[2] On the RPI range: the mains frequency is below the allowed limit, so the inverter has disconnected. A network event; it reconnects by itself. Safe steps in the lookup	Wait and watch
E09Delta Solivia E09	No mains at the inverter (RPI)^[2] On the RPI range: the inverter cannot see any mains voltage. Normal during a blackout; otherwise the solar supply breaker is off or tripped, the AC plug is loose, or an internal fuse has blown. Safe steps in the lookup	Wait and watch
E10Delta Solivia E10	Grid voltage low (RPI)^[2] On the RPI range: the mains voltage is below the allowed limit, so the inverter has disconnected. It reconnects by itself once the supply recovers. Safe steps in the lookup	Wait and watch
F01Delta Solivia F01	DC offset into the grid (RPI)^[2] On the RPI range: too much DC in the current the inverter sends to the grid. A distorted mains waveform from nearby loads can cause it; if it repeats with a clean supply the detection circuit inside is faulty. DC on the AC side is a protection fault, so we treat it as a call. Safe steps in the lookup	Stop and call

Panel input and power output error codes 4 codes

The DC input from the panels and the power the unit puts out: string voltage, low light, overloads and output limits. 2 worth a look, 2 wait and watch.

Error code	What it means	What to do
Block selectionDelta Solivia Block selection	Display buttons locked^[1] The buttons have locked because nothing was pressed for five minutes. Production is not affected. The manual unlocks them by switching the DC off and on again, which is the normal restart sequence. Safe steps in the lookup	Worth a look
No displayDelta Solivia No display	Inverter not starting^[8] The screen is blank and the inverter is not producing. Delta's own guide says it is either not getting enough voltage from the panels to start (an isolator off, or a roof-side fault) or the inverter itself has failed. An electrician settles it with one measurement at the DC input. Safe steps in the lookup	Worth a look
PV power too lowDelta Solivia PV power too low	Not enough panel power^[9] The panels are not giving the inverter enough power, which is normal at dawn and dusk and under heavy cloud. In good sun it points to a roof-side problem or, if the panel voltage is fine but the current reads zero, a failed inverter. Safe steps in the lookup	Wait and watch
PV voltage too lowDelta Solivia PV voltage too low	Panel voltage below start level^[1] The panel voltage is between 100 and 150 V, which is below the inverter start level. Normal in low light; in good sun it means a string is down. Safe steps in the lookup	Wait and watch

Panels, insulation and earth faults error codes 7 codes

Insulation, earth and leakage faults on the solar panel side. These are safety faults: live DC wiring may be leaking to earth somewhere on the roof. 7 stop and call.

Error code	What it means	What to do
E34Delta Solivia E34	Ground fault (RPI)^[2] On the RPI range: an insulation fault on the panels or DC cabling, or a very wet array leaking to earth. Live DC, so leave it to an electrician. Safe steps in the lookup	Stop and call
Error # 506Delta Solivia Error # 506	Insulation fault while running, inverter stopped^[1] The DC side failed its insulation test while running and the inverter has tripped. The leak is almost always on the roof: water in a panel, isolator or connector. Live DC, so leave it to an electrician. Safe steps in the lookup	Stop and call
Error # 508Delta Solivia Error # 508	Insulation fault at start-up, inverter stopped^[1] The DC side failed its insulation test at start-up and the inverter has tripped rather than just warning. The leak is almost always on the roof: water in a panel, isolator or connector. Live DC, so leave it to an electrician. Safe steps in the lookup	Stop and call
F24Delta Solivia F24	Residual current too high (RPI)^[2] On the RPI range: the inverter measured too much current leaking to earth, which is an insulation fault on the array or a very wet array. Live DC, so leave it to an electrician. Safe steps in the lookup	Stop and call
Isolation running warningDelta Solivia Isolation running warning	Insulation fault while running^[6] While running, the inverter measured low insulation between the panels or DC cabling and earth and has lit the red Earth Fault light. It keeps producing, but Delta warns there is live DC leaking somewhere, usually water in a connector, isolator or panel, so do not touch the system and have it checked. Safe steps in the lookup	Stop and call
Isolation start-up warningDelta Solivia Isolation start-up warning	Insulation fault at start-up^[7] When it started up, the inverter measured low insulation between the panels or DC cabling and earth, and has lit the red Earth Fault light. Delta says the inverter is almost always fine and the leak is on the roof: moisture in a panel, isolator or connector. The unit may still be producing, but there is live DC leaking somewhere, so do not touch anything and have it checked. Safe steps in the lookup	Stop and call
PV+ / PV- grounding faultDelta Solivia PV+ / PV- grounding fault	Array earthing fault^[1] On systems where one side of the array is earthed through the inverter, that earth connection is broken or on the wrong pole, or its fuse has blown. The inverter keeps producing, but it is an electrician job to check the earthing and the fuse. Safe steps in the lookup	Stop and call

Heat and cooling fans error codes 2 codes

Over-temperature, heat derating and the cooling fans. Heat faults are taken seriously: a unit that cannot cool itself can be a fire risk. 2 stop and call.

Error code	What it means	What to do
Error # 302Delta Solivia Error # 302	Over temperature^[1] The inverter is too hot and has tripped; it goes back to producing once it cools. Direct sun on the unit or no air movement around it is the usual cause. If it happens on mild days the temperature sensing is faulty. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call. Safe steps in the lookup	Stop and call
F05Delta Solivia F05	Over temperature (RPI)^[2] On the RPI range: the inverter is above 60 degrees and has stopped until it cools. Direct sun or no air movement is the usual cause; on mild days the sensor is faulty. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call. Safe steps in the lookup	Stop and call

Internal hardware and safety checks error codes 8 codes

The unit's own electronics: relays, sensors, the DC bus, memory and its self-checks. Nearly all of these need an electrician. 6 stop and call, 1 worth a look, 1 wait and watch.

Error code	What it means	What to do
AC relay failureDelta Solivia AC relay failure	Output relay failed^[1] One of the relays that joins the inverter to the grid has failed. The Delta manual is blunt: the inverter is defective and must be returned. Nothing to try at home. Safe steps in the lookup	Stop and call
Calibration ongoingDelta Solivia Calibration ongoing	Normal start-up check^[1] The inverter is checking its internal settings before it connects, which is normal each morning. Only a problem if it never moves past this screen. Safe steps in the lookup	Wait and watch
Display communication faultyDelta Solivia Display communication faulty	Display not talking to the inverter^[1] All three lights are on and the screen shows nothing useful because the display has lost contact with the inverter. Try one reset; if it stays like this it needs a service visit. Safe steps in the lookup	Worth a look
Error # 301Delta Solivia Error # 301	Internal communication or hardware fault^[5] A communication error or hardware fault inside the inverter. The manual says try one reset; Delta Australia treats it as a replacement if it comes back. Safe steps in the lookup	Stop and call
F28Delta Solivia F28	Output relay stuck closed (RPI)^[2] On the RPI range: one of the grid relays inside the inverter is sticking closed. The manual's fix is to replace the relay, which is a service centre job. Safe steps in the lookup	Stop and call
F29Delta Solivia F29	Output relay stuck open (RPI)^[2] On the RPI range: one of the grid relays inside the inverter will not close. The manual's fix is to replace the relay, which is a service centre job. Safe steps in the lookup	Stop and call
Revision errorDelta Solivia Revision error	Hardware and software mismatch^[1] The inverter firmware and hardware versions do not match, usually after a board or firmware change. One reset is worth a try; otherwise it needs a service visit. Safe steps in the lookup	Stop and call
Varistor warningDelta Solivia Varistor warning	Internal surge protection spent^[1] The surge protection part on the DC input inside the inverter has failed, usually after a storm. The manual says it can keep running for now but the part must be replaced soon, which means the unit goes back to a service centre. Safe steps in the lookup	Stop and call

Got a Delta Solivia error code? Free phone diagnosis in our service area

Our own licensed electricians cover Greater Adelaide and regional SA, and from North Brisbane up through the Sunshine Coast to Gympie. Check your postcode, then read us the code and tell us the install year. If it needs a visit, the callout is credited against the work.

How to reset a Delta Solivia inverter safely

Try one restart, in this order:

Switch the solar supply main switch off at the switchboard.
Switch the DC isolator off at the inverter.
Wait five minutes.
Switch the DC isolator back on, then the solar supply main switch.

Never open the unit or touch the wiring. Never restart anything that smells hot or shows scorch marks. If the code comes back after one restart, stop and call.

Delta Solivia inverter repair or replacement?

On a visit, our electricians test the whole system before condemning the inverter: insulation resistance on every string, earth continuity, the relay, DC string voltages and currents, the AC supply and the unit's own fault log. An Isolation start-up warning or Error # 508 is a good example of why: Delta itself says the inverter is almost always fine and the leak is on the roof, and fixing that leak is a repair, not a replacement.

When the fault is inside the inverter, such as a failed relay (F28 or AC relay failure) or an Error # 301 that keeps coming back, Delta's limited support means there is rarely a part to fit. We quote a straight replacement and a hybrid option side by side, so a battery can go in now or later. The callout comes off whichever you choose, and your panels usually stay.

We do this work in Adelaide, the Adelaide Hills, Gawler, the Barossa, the Fleurieu, Murray Bridge and Yorke Peninsula in South Australia, or North Brisbane, Caboolture, Bribie Island, the Sunshine Coast, Noosa and Gympie in Queensland only. Outside those areas, everything above still applies: take the code, its meaning and the urgency to a licensed electrician near you.

Where these Delta Solivia error codes come from

Every Delta Solivia code on this page was read from the maker's own manual. The numbers match the references in the code table.

[1]
Delta SOLIVIA 3.0 AP G3 TR Operation and installation manual (software 2.46.25)12 codes, from the maker's own document
[2]
Delta RPI H3A / H5A Operation and Installation Manual (ManualsLib copy)10 codes, from the maker's own document
[3]
Delta Energy Systems Australia support knowledge base: AC Voltage Failure1 code, from the maker's own document
[4]
Delta Energy Systems Australia support knowledge base: DC Injection Failure1 code, from the maker's own document
[5]
Delta Energy Systems Australia support knowledge base: Error #3011 code, from the maker's own document
[6]
Delta Energy Systems Australia support knowledge base: Isolation Running Warning1 code, from the maker's own document
[7]
Delta Energy Systems Australia support knowledge base: Isolation Start-up Warning1 code, from the maker's own document
[8]
Delta Energy Systems Australia support knowledge base: No Display1 code, from the maker's own document
[9]
Delta Energy Systems Australia support knowledge base: PV Power Too Low1 code, from the maker's own document

Tables last updated 21 October 2026

Delta Solivia error code questions, answered

How do I read a Delta Solivia error code?

Write down the exact words or the Error # number on the display and find them in the table. On an RPI, look for a letter and two digits, such as E10 or F05. If the only sign is the red Earth Fault light, read the two isolation warning rows: that light is the inverter’s insulation alarm.

What does Delta Solivia Isolation start-up warning mean?

Isolation start-up warning is “insulation fault at start-up”. When it started up, the inverter measured low insulation between the panels or DC cabling and earth, and has lit the red Earth Fault light. Delta says the inverter is almost always fine and the leak is on the roof: moisture in a panel, isolator or connector. The unit may still be producing, but there is live DC leaking somewhere, so do not touch anything and have it checked. We rate it stop and call. See it in the table.

What does Delta Solivia No display mean?

No display is “inverter not starting”. The screen is blank and the inverter is not producing. Delta’s own guide says it is either not getting enough voltage from the panels to start (an isolator off, or a roof-side fault) or the inverter itself has failed. An electrician settles it with one measurement at the DC input. We rate it worth a look. See it in the table.

Do you cover my area?

We work in Adelaide, the Adelaide Hills, Gawler, the Barossa, the Fleurieu, Murray Bridge and Yorke Peninsula in South Australia, or North Brisbane, Caboolture, Bribie Island, the Sunshine Coast, Noosa and Gympie in Queensland. Check your postcode to be sure. Outside those areas, this page still tells you what your code means and how urgent it is, and a licensed electrician near you can take it from there.

What does it cost to have a Delta Solivia looked at?

For homes in our service area, the phone diagnosis is free. If it needs a visit, there is a callout fee, and it is credited against any repair or replacement we do.

Will you work on a Delta Solivia you did not install?

Yes, if it is in our service area. Most of our repair work is on systems someone else installed. We test the whole system, not just the unit on the wall.

Is a Delta Solivia worth repairing?

It depends where the fault is. Faults outside the inverter, like a wet roof connector, a tripped switch or high grid voltage, are worth fixing and the Delta carries on. Faults inside it, like a failed relay or a spent surge protection part, usually are not, because Delta has left the market. We will tell you which on the phone.

Can I keep my panels if my Delta is replaced?

Usually, yes. In most replacements the panels stay where they are and the new inverter connects to them. We test the panels and their wiring first, so you know they are worth keeping, and a hybrid inverter lets you add a battery now or later.

Where do the codes on this page come from?

Every code comes from Delta’s own documents: the Solivia and RPI operation and installation manuals, and the Delta Energy Systems Australia support knowledge base. Each code in the table carries a numbered reference to its document in the source list.

Written by

Joe Deionno

Started in 2017 after years of subcontracting and seeing the dodgy operators at work; set out to be the installer people could trust. Oversees every install in both states.

Related guides

More solar repairs guides from our electricians.

All solar repairs guides

Swipe to see more

Inverter faults · 5 min read

The Complete Guide To Omnik Inverter Error Codes

All 20 Omnik and Trannergy error codes in plain English: what each one means, how urgent it is, how to restart safely, and what your replacement options are now Omnik and its portal are gone.

Inverter faults · 5 min read

The Complete Guide To Error Codes On Older Inverter Brands

All 130 error codes we hold for twelve older inverter brands, from Sunny Roo and SolarMax to KACO, Danfoss and Xantrex, in plain English: what each one means, how urgent it is, how to reset safely, and what your replacement options are.