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Inverter fault · All brands

Inverter not turning on

No lights. No display. No response. A completely dead inverter has several possible causes — and the most common ones don't require an engineer. Before assuming hardware failure, work through the power supply checks below.
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  • Check power before assuming failure
  • Normal to be dark at night
  • Do not open the inverter
Confirmed dead despite all power being present?

If AC supply, DC isolator, and MCBs are all correct but the inverter is still dead, it needs an engineer assessment. Hardware failure diagnosis and repair is usually needed.

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Safety: do not open the inverter enclosure. Internal components include live high-voltage DC even when the AC supply is isolated. See our shutdown guide for safe isolation procedures.

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Rated 5.0 on Google Read all 73 reviews

Ron is incredibly knowledgeable about solar installs in general but knows givenergy products inside out and the key personnel that worked there from the start to the end. My problem was spurious in its nature but Ron spotted it straight away when he understood the installation details. In essence the installers didn’t fit the correct trip switch. He also gave me hope that in the future hardware repairs could be possible but it’s still early days. This guy really is in the know and keen to sucas a business If you need help don’t hesitate

Geoffrey Heathcote · Jun 2026 Google

After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.

Keith Ballard · Apr 2026

Ron very quickly diagnosed what was wrong with my GivEnergy system. Unfortunately the kit has died after only 3.5 years of use-which is quite sad and timing couldn’t be worse with GivEnergy gone bust. Ron gave me advise on how to handle this with my installer. I’m hoping they’ll be forthcoming, but if they aren’t i now have a good idea how to deal with that. Thanks a lot Ron!

Dennis Koenen · Jul 2026 Google

Absolutely wonderful support. I have a GivEnergy system that was installed in 2022, and a firmware update was flagged in the app, so I proceeded to update the software .... and immediately regretted it, as my inverter came up with an error, and was not working at all! With no GivEnergy support available, and my installer saying there was nothing he could do, I googled help, and found Ron. What a stroke of good luck! Submitted an on line enquiry late morning, and received phone call just after 5 pm, and later that evening Ron was able to supply me with old firmware no longer available on the GivEnergy web site. I was then able to update the firmware using a GivEnergy youtube video as reference, and hey presto the system was back up and running. One further slight adjustment by Ron and we are back normal. What a relief. I have no hesitation in recommending Solar Tech Support if you have a problem. Great service! And if you are a GivEnergy system owner, whatever you do, DO NOT UPDATE FIRMWARE!

Neill Ginn · Jul 2026 Google

My Givenergy system went offline, so I lost control of it. Ron from STS and Craig from Norfolk Solar were most helpful in diagnosing the problem by phone. Full marks for their patience and ability.

Tony Jackson · Jul 2026 Google

After recently changing my fuse board the ct clamp broke, this meant my inverter was not communicating properly with my GivEnergy system. After several people letting me down, finally got put in touch with Ron. He came out within 24hours & resolved the fault within an hour, no fuse just got on with it. Work was tidy & arrived when he said he would. Ron followed up a few days later to confirm all was still good, great service from all involved.

Mr Paddy · Jul 2026 Trustpilot

Checking at night? Grid-tied solar inverters shut down completely at night — no lights, no display. This is completely normal. Wait until there is at least some daylight (even overcast) before concluding the inverter has a fault. Many early-morning calls turn out to be owners checking at 6am before sunrise.

Why an inverter won't start

Starting with the simplest and most common causes.

AC isolator turned off

Most common cause. The AC solar isolator has been switched to OFF — after a maintenance visit, a power cut, or accidentally. Turn it back on and wait 3 minutes.

MCB tripped in consumer unit

The solar circuit breaker in the consumer unit has tripped. Look for a breaker in the mid or down position. Reset once — if it trips again, call an electrician.

DC isolator turned off

On some inverter models the control electronics are powered by the DC string. If the DC isolator is off, the inverter has no power at all, even if the AC supply is present.

No grid supply (power cut)

Grid-tied inverters require the grid to start. During a power cut the inverter will not operate. It will restart automatically when the grid supply returns.

Power surge damage

A lightning proximity event or grid switching transient has damaged internal components. The inverter was working, then a storm or grid event occurred, and it has been dead since. Requires engineer diagnosis.

Inverter hardware failure

The inverter itself has failed — capacitor degradation, failed power supply board, or IGBT failure. More common on inverters over 8–10 years old. Requires component-level diagnosis.

Power supply checks — do these first

Do these checks during daylight hours only.

1
Check the AC isolation switch

Find the AC solar isolator — usually a red rotary switch mounted near the consumer unit or solar generation meter. Check it is in the ON (I) position. If it is in the OFF (O) position, turn it on. Wait 2–3 minutes for the inverter to initialise and begin startup checks.

2
Check the consumer unit

Open the consumer unit and look for any MCB in the tripped position (mid or down) labelled Solar, PV, or Inverter. Also check the main RCD or RCBO. Reset any tripped breaker once. If it holds, wait for the inverter to start. If it trips again immediately, leave it and call an electrician.

3
Check the DC isolator

Locate the DC isolator on or near the inverter. It should be in the ON position. If it is OFF, turn it on. On some inverter models this is the primary power source for the control electronics.

4
Confirm grid power is present

Check that other appliances in the house have power. If the grid is down, the inverter will remain dark until it returns. Most inverters wait 60–90 seconds after grid restoration before attempting reconnection — this is a G98/G99 requirement.

5
If all power sources confirmed — book a diagnostic

If the AC supply is present, the DC isolator is on, the MCBs are healthy, and there is no power cut — but the inverter is still completely dark — the inverter itself has likely failed. This requires component-level diagnosis and cannot be self-resolved. A remote diagnostic session will confirm the situation before an engineer visit is arranged.

Brand-specific startup notes

Inverter startup requirements differ by manufacturer. Use the note for your brand before working through a full fault investigation.

GivEnergy

GivEnergy AIO and Gen2 hybrid inverters require both AC isolation (consumer unit breaker) and DC isolation (rooftop DC switch) to be live before the unit will boot. A blank display with power present usually means DC voltage is not reaching the inverter — check the DC switch and any inline fusing. See the GivEnergy hub for detailed startup checks.

Growatt

Growatt SPH and MIN series inverters require a complete L/N/E AC connection before the unit will start — a missing Neutral or an open AC output breaker prevents boot entirely. If the display stays blank, verify the AC output terminal block connections at the inverter before investigating further.

Sunsynk / Deye

Sunsynk inverters include an internal AC output circuit breaker accessible via a small hatch on the unit. This breaker occasionally trips on surge events and is easy to miss. If the inverter receives DC power but does not boot, check and reset the internal breaker before investigating further.

Related

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FAQ

Frequently asked questions

A completely dark inverter means it has no power. Check: the AC isolation switch, any tripped MCBs in the consumer unit, the DC isolator, and whether the house has grid power. These are the four most common causes and all are fixable without an engineer.
Yes — grid-tied inverters shut down completely at night. A dark inverter at 11pm is not a fault. Check it during daylight hours, ideally when the sky is at least partly clear. Some inverters take 15–20 minutes after sunrise to start generating.
Sudden death is often caused by: a power surge from lightning or a grid event; an internal fuse blowing due to a wiring fault; or the AC supply being interrupted (tripped MCB, switched isolator). Check the consumer unit and isolators first. If a storm occurred at the same time, surge damage to the inverter electronics is possible.
Most inverters are rated 10–15 years. String inverters commonly develop faults between years 8 and 12 due to capacitor degradation. If your inverter is over 10 years old and has failed, replacement may be more cost-effective than repair depending on the fault type — a diagnostic will advise.
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Inverter confirmed dead — what next?

A remote session reviews whatever portal data is available and confirms the situation before recommending the right on-site service. For a non-responsive inverter, an emergency repair visit may be appropriate.

  • Independent — not affiliated with any manufacturer
  • Emergency repair available
  • Remote check before any visit arranged

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