FlexBoss21 / GridBoss Issue List

[Zerog2k]

Thinking about creating a separate forum post for this in case anyone else has run across this issue.
I have GridBoss + FlexBoss21. Latest firmware on both.
I just had the system commissioned a few days ago, and I'm not exporting, awaiting PTO.
I have 3 large loads hooked up to Smart Ports 1-3. They were configured as smart ports, based on SOC (100-20%), enabled, and set to grid always on. These were working (and the SP1-SP3 lights illuminated on the GB front panel).
After a shutdown & cold start of both GB + FB, I found that the SP1-SP3 relays were not closed & status lights off. (No faults for OC or anything else recorded in monitor.)
No matter what I did with enabling/renabling of the SPs in GB settings, they would not come on. I even did a complete power down of the GB, did not help. Even switching port modes to Unused and back to Smart Load did nothing.
The only thing that resolved this was setting the "Smart load based on" from "SOC/Volt" to "Timed" then back to SOC, for each of the ports.
The port only came on when it was switched back to SOC from Timed.

I believe this is some kind of bug, and was _very_ concerning because all indications of the monitor & settings were that the SP1-SP3 should have been closed/on, but they were not. Not sure even how to reproduce, and I don't want to (this thing has too many quirks already) - but just posting here in case anyone else has encountered this.

 

[Tommytwotone]

Thinking about creating a separate forum post for this in case anyone else has run across this issue.
I have GridBoss + FlexBoss21. Latest firmware on both.
I just had the system commissioned a few days ago, and I'm not exporting, awaiting PTO.
I have 3 large loads hooked up to Smart Ports 1-3. They were configured as smart ports, based on SOC (100-20%), enabled, and set to grid always on. These were working (and the SP1-SP3 lights illuminated on the GB front panel).
After a shutdown & cold start of both GB + FB, I found that the SP1-SP3 relays were not closed & status lights off. (No faults for OC or anything else recorded in monitor.)
No matter what I did with enabling/renabling of the SPs in GB settings, they would not come on. I even did a complete power down of the GB, did not help. Even switching port modes to Unused and back to Smart Load did nothing.
The only thing that resolved this was setting the "Smart load based on" from "SOC/Volt" to "Timed" then back to SOC, for each of the ports.
The port only came on when it was switched back to SOC from Timed.

I believe this is some kind of bug, and was _very_ concerning because all indications of the monitor & settings were that the SP1-SP3 should have been closed/on, but they were not. Not sure even how to reproduce, and I don't want to (this thing has too many quirks already) - but just posting here in case anyone else has encountered this.

When you powered down the GB to try to remedy the issue did you pwercdwon the inverter as well?

 

[Zerog2k]

When you powered down the GB to try to remedy the issue did you pwercdwon the inverter as well?

Yes, both were completely powered down, and it happened after powering them up.
When powering GB off a second time to try to resolve, I had the Hybrid Inverter 1 breaker open on the GB - the GB was completely dark (even dongle lights on GB were off). FB was probably still on, but GB was completely dark.

 

[Tommytwotone]

Yes, both were completely powered down, and it happened after powering them up.
When powering GB off a second time to try to resolve, I had the Hybrid Inverter 1 breaker open on the GB - the GB was completely dark (even dongle lights on GB were off). FB was probably still on, but GB was completely dark.

A good practice is to shut off the system with everything including batteries powered down. Once it is all off set a timer for 5 minutes wait and after that follow the correct start up procedure.

I had a number of issues with my system, they were v1s at the time and had to be replaced, and the 5 minute full soft reset was what I had to do.

If you powered it off and right back on it does not really reset the system as there is still power in the caps etc etc.

Realizing you just powered up I will share the following.

These systems do NOT always behave as programmed. The v1 units I had to swap out for v2s were really bad and the v2s are much much better. At the same time I had an issue about a week ago where they only charged the batteries to 97% one day. Why? I don't know. I was concerned about it but the next day the system charged to 100% SOC and has been fine since.

I feel your pain in things not working as set for sure.

The other thing, assuming things get really bad, is to talk with SS and do a full reset which will take it to factory and then back up to where you are. Knowing that these things will sometimes just misbehave or get caught in a loop of some kind trying to soft reset etc etc can help.

Lastly being off grid can impact things. When I switched to on grid and sell back after getting PTO things settled in a little better I think.

 

[comet48]

Was looking to purchase GB and FB21 but it looks like a bit of mess. Nothing worse that lousy manuals/crappy software. I also have two Enphase strings and the support for AC connect looks pretty questionable as well. Hopefully they sort this out before the solar incentives disappear!

 

[zanydroid]

I wouldn’t be surprised if the uncertainty about the U.S. market causes LuxPower to pull back on US-specific feature development and bug fixing

 

[Zapper77]

Thinking about creating a separate forum post for this in case anyone else has run across this issue.
I have GridBoss + FlexBoss21. Latest firmware on both.
I just had the system commissioned a few days ago, and I'm not exporting, awaiting PTO.
I have 3 large loads hooked up to Smart Ports 1-3. They were configured as smart ports, based on SOC (100-20%), enabled, and set to grid always on. These were working (and the SP1-SP3 lights illuminated on the GB front panel).
After a shutdown & cold start of both GB + FB, I found that the SP1-SP3 relays were not closed & status lights off. (No faults for OC or anything else recorded in monitor.)
No matter what I did with enabling/renabling of the SPs in GB settings, they would not come on. I even did a complete power down of the GB, did not help. Even switching port modes to Unused and back to Smart Load did nothing.
The only thing that resolved this was setting the "Smart load based on" from "SOC/Volt" to "Timed" then back to SOC, for each of the ports.
The port only came on when it was switched back to SOC from Timed.

I believe this is some kind of bug, and was _very_ concerning because all indications of the monitor & settings were that the SP1-SP3 should have been closed/on, but they were not. Not sure even how to reproduce, and I don't want to (this thing has too many quirks already) - but just posting here in case anyone else has encountered this.

Your Start SOC needs to be adjusted or lowered. The Smart Port(s) won't turn on until the battery reaches 100%. I use Start 40% and Stop 20%.

 

[CaySol]

Your Start SOC needs to be adjusted or lowered. The Smart Port(s) won't turn on until the battery reaches 100%. I use Start 40% and Stop 20%.

I missed that in his comment as mine works as expected. For example I have a ev charger to start above 75% and stop at 50%. The manual explains it as well as it can be in my opinion it’s just that it isn’t a common way to control a setting in my experience. But it allows greater control and I understand why it works this way.

 

[SunDave]

If it wasn't set up with a stop start, I could see it enabling at 20%, then immediately disabling due to draw, then enabling, over and over again. The start being sufficiently separated from the stop prevents that short cycling.

These nuances are hard to explain, but important. I could easily see thinking that it just works within the range set.

 

[skimandan]

It appears my FlexBoss21 failed last night at 19:54. Its had been working as programmed for a few months and then suddenly stopped doing any operations that involved the battery. I called Signature Solar this morning and they had me perform some diagnostics, had me disconnect the battery cables, and then put my system in a batteryless mode so the PV would function. I am currently waiting for Signature Solar to contact me with more diagnostic requests or warranty replacement. We had temperatures in the 90's yesterday and my garage where the inverter is located could have gotten hotter, but the SS tech did not think it was a contributing factor.

It first threw W027 Battery Open code, and then threw a W026 low voltage code a few minutes later.

I am only posting in this thread because I am the original poster that started the thread. The SS tech was very good and we'll see how they handle it from here. In the meantime I have no battery backup for the heat related outages and I get to pay peak TOU rates instead of drawing from my batteries. I also get to wonder about the reliability of the hardware and the warranty support when it fails.

Please reserve judgement until the issue is resolved. As far as I know this is just a sample of 1.

 

[SunDave]

Sorry to hear it. Hope you get a good resolution.

 

[42OhmsPA]

It appears my FlexBoss21 failed last night at 19:54. Its had been working as programmed for a few months and then suddenly stopped doing any operations that involved the battery. I called Signature Solar this morning and they had me perform some diagnostics, had me disconnect the battery cables, and then put my system in a batteryless mode so the PV would function. I am currently waiting for Signature Solar to contact me with more diagnostic requests or warranty replacement. We had temperatures in the 90's yesterday and my garage where the inverter is located could have gotten hotter, but the SS tech did not think it was a contributing factor.

It first threw W027 Battery Open code, and then threw a W026 low voltage code a few minutes later.

I am only posting in this thread because I am the original poster that started the thread. The SS tech was very good and we'll see how they handle it from here. In the meantime I have no battery backup for the heat related outages and I get to pay peak TOU rates instead of drawing from my batteries. I also get to wonder about the reliability of the hardware and the warranty support when it fails.

Please reserve judgement until the issue is resolved. As far as I know this is just a sample of 1.

That sucks. Hope they get you taken care of quickly. How many MWhs of solar / load did you have through it?

 

[Tommytwotone]

It appears my FlexBoss21 failed last night at 19:54. Its had been working as programmed for a few months and then suddenly stopped doing any operations that involved the battery. I called Signature Solar this morning and they had me perform some diagnostics, had me disconnect the battery cables, and then put my system in a batteryless mode so the PV would function. I am currently waiting for Signature Solar to contact me with more diagnostic requests or warranty replacement. We had temperatures in the 90's yesterday and my garage where the inverter is located could have gotten hotter, but the SS tech did not think it was a contributing factor.

It first threw W027 Battery Open code, and then threw a W026 low voltage code a few minutes later.

I am only posting in this thread because I am the original poster that started the thread. The SS tech was very good and we'll see how they handle it from here. In the meantime I have no battery backup for the heat related outages and I get to pay peak TOU rates instead of drawing from my batteries. I also get to wonder about the reliability of the hardware and the warranty support when it fails.

Please reserve judgement until the issue is resolved. As far as I know this is just a sample of 1.

Sorry to hear about your issue. I will say I had an issue with my GB/Flexboss system and after going through tech support and the whole process to diagnose the problem EG4 did issue an RMA.

The new units are in, running and so far so good.

The swap was fun.

Did you have v1 or v2 out of curiosity? I don’t remember and it can matter.

 

[skimandan]

That sucks. Hope they get you taken care of quickly. How many MWhs of solar / load did you have through it?

8MWh PV
3MWh battery charge.

Battery was charged/discharged at 4kW most of the time. Well below the 12kW max. The tech seemed to be familiar with an issue with the battery breaker or internal communication of the breaker position.

Did you have v1 or v2 out of curiosity? I don’t remember and it can matter.

I ordered mine in December. How can you tell which version?

 

[42OhmsPA]

8MWh PV
3MWh battery charge.

Battery was charged/discharged at 4kW most of the time. Well below the 12kW max.

That doesn't seem like much at all.

The tech seemed to be familiar with an issue with the battery breaker or internal communication of the breaker position.

It's good they are familiar with it, hopefully they are making corrections to future models if it's a known issue.
Good luck.

 

[Tommytwotone]

8MWh PV
3MWh battery charge.

Battery was charged/discharged at 4kW most of the time. Well below the 12kW max. The tech seemed to be familiar with an issue with the battery breaker or internal communication of the breaker position.


I ordered mine in December. How can you tell which version?

Is the back part of the case black? If so v1. I am referring to the part that you see from the outside that goes against the wall that the front panels attach to.

The v2 units are all grey door, back cabinet etc.

 

[CaySol]

It appears my FlexBoss21 failed last night at 19:54. Its had been working as programmed for a few months and then suddenly stopped doing any operations that involved the battery. I called Signature Solar this morning and they had me perform some diagnostics, had me disconnect the battery cables, and then put my system in a batteryless mode so the PV would function. I am currently waiting for Signature Solar to contact me with more diagnostic requests or warranty replacement. We had temperatures in the 90's yesterday and my garage where the inverter is located could have gotten hotter, but the SS tech did not think it was a contributing factor.

It first threw W027 Battery Open code, and then threw a W026 low voltage code a few minutes later.

I am only posting in this thread because I am the original poster that started the thread. The SS tech was very good and we'll see how they handle it from here. In the meantime I have no battery backup for the heat related outages and I get to pay peak TOU rates instead of drawing from my batteries. I also get to wonder about the reliability of the hardware and the warranty support when it fails.

Please reserve judgement until the issue is resolved. As far as I know this is just a sample of 1.

What was the last voltage of the batteries when it threw the error. Are you in SOC mode or voltage?

 

[skimandan]

What was the last voltage of the batteries when it threw the error. Are you in SOC mode or voltage?

52.4V and 62% SOC. I use SOC mode for charge and discharge.

 

[skimandan]

Is the back part of the case black? If so v1. I am referring to the part that you see from the outside that goes against the wall that the front panels attach to.

The v2 units are all grey door, back cabinet etc.

V2

 

[Tommytwotone]

V2

That makes your life easier. As they are on v2 currently if they warranty out the inverter you have a match v2 GB with v2 FB.

I was thinking they would be v2 units due to the very limited run of v1 units and when you ordered I believe all the v1 units were already shipped/spoken for.

 

[RARankin]

Ooph. Mine are V1. If I want to expand and add inverters in the future can I add a V2 FB in parallel with my V1 FB?

 

[skimandan]

FedEx should be delivering my warranty replacement this Friday. It’s another disappointment given I thought the hardware was solid and the software was “sub-optimal”.

Here is the thread of other experiencing the battery open / low voltage errors:

A

Thread 'Flexboss21 battery open battery low warning issue'

Apr 25, 2025

I have a Gridboss/Flexboss combo with 2 powerpro wall batteries and an ac coupled enphase system.
Last night, around 7pm, when transitioning from solar to battery, the Flexboss threw a W027 (battery open) and W026 (battery voltage low) at 86% SOC, around 53.6V.
Tried restarting multiple times, with correct boot sequence.
Tested the battery voltage at the terminals and 53.3V across both pos and neg. Tested for a short with battery cables removed and battery breaker on at the inverter, 0L on multimeter.
Tried to start with just the master battery on. No luck.
Called SS this morning to...

• AC-CoupleThis
• Replies: 55
• Forum: DIY Solar General Discussion

Will EG4 be around for the next 10 years to honor the warranty?

 

[Tommytwotone]

FedEx should be delivering my warranty replacement this Friday. It’s another disappointment given I thought the hardware was solid and the software was “sub-optimal”.

Here is the thread of other experiencing the battery open / low voltage errors:

A

Thread 'Flexboss21 battery open battery low warning issue'

Apr 25, 2025

I have a Gridboss/Flexboss combo with 2 powerpro wall batteries and an ac coupled enphase system.
Last night, around 7pm, when transitioning from solar to battery, the Flexboss threw a W027 (battery open) and W026 (battery voltage low) at 86% SOC, around 53.6V.
Tried restarting multiple times, with correct boot sequence.
Tested the battery voltage at the terminals and 53.3V across both pos and neg. Tested for a short with battery cables removed and battery breaker on at the inverter, 0L on multimeter.
Tried to start with just the master battery on. No luck.
Called SS this morning to...

• AC-CoupleThis
• Replies: 55
• Forum: DIY Solar General Discussion

Will EG4 be around for the next 10 years to honor the warranty?

Let's just say I have wondered the same thing. One would hope they would last to payback plus a margin. I am wondering if that is reality.

If you are on net metering who wants to redo the dance with the POCO any more often than you have to. You touch it you have to bring it all up to CURRENT code again. Oh joy.

I had to swap mine out under warranty. I applaud EG4 for doing the warranty without to much fuss, once they got going it was not bad at all, and my distributor made my life easy.

So like you I wonder if the units will live long enough to pay for themselves. I hope so. Plenty of people have Solark's and EG4 units that seem to be doing very well....but........

I hope your swap goes well.