Good Afternoon,
I was having issues with the data logger registers freezing when making updates to the Mode Scheduler. So contacted Fox support. They created a ticket said they will upgrade the inverter which was 3hrs ago and looks to have failed. At the moment the versions on the app are showing as:
Master : 1.50 Slave : 0.00 Manager : 1.51
I think elsewhere on this site that these versions are not compatible with UK hardware? viewtopic.php?t=1927
I have an error message on the display of MDSP SPI Fault I haven't had a reply on the ticket yet. Is there anything else I can do to fix this?
The slave firmware has failed and will need to be resent and installed remotely again by Fox or your installer.
If you're UK based and fancy having your system properly managed I do offer this as a service https://ecclessolar.com/digital-services/
If you're UK based and fancy having your system properly managed I do offer this as a service https://ecclessolar.com/digital-services/
Community Admin / FoxESS Elite Professional
Did I help you? Feel free to leave me a tip
Book a zoom meeting for remote consultancy or help
Switch to Octopus and earn £50
Get a heatpump from Octopus and earn £100
Subscribe to my YouTube channel
Fox ESS Tri Inverter Installation
2 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
Dual Tesla Household
Heatpump & Low Carbon Housebuild
Fox ESS Tri Inverter Installation
2 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1
24 x HV2600 (62.4kWh)
32 x 490w across 4 arrays
Dual Tesla Household
Heatpump & Low Carbon Housebuild
Thanks Will, hopefully they will get back to me on the ticket.
Just a quick update. This was working again at 8:05am the next morning, with a notification from Fox Support, so all good. Hopefully the update will help with the mode scheduler update issues...
See Below 
Last edited by chubber on Thu Oct 23, 2025 4:20 pm, edited 1 time in total.
So to summarise the new issues after the Firmware upgrade of my KH8 Inverter.
Master : 1.50 Slave : 1.02 Manager : 1.51
I am on Octopus Intelligent Go:
• Setting a force charge stopped working with the new Firmware. I had to add a high Force Discharge Power to the time slot to get this to work. This doesn’t make sense as it handled charge power itself before (?)
• If Force Charging during the day (e.g. Free Electricity Session) the Solar was still used, and less was taken from the Grid. Now after the update, Solar seems to be disabled for the duration of the slot. Wasting Solar energy, again this worked fine before.
I am on Agile Export
• Before the update, I could set a force discharge to a certain FD SoC e.g. 30% to leave enough battery for the evening until the cheap slot again. This worked perfectly.
• Now after the FD SoC is reached it uses Grid import for the remainder of the slot, which could get expensive.
Master : 1.50 Slave : 1.02 Manager : 1.51
I am on Octopus Intelligent Go:
• Setting a force charge stopped working with the new Firmware. I had to add a high Force Discharge Power to the time slot to get this to work. This doesn’t make sense as it handled charge power itself before (?)
• If Force Charging during the day (e.g. Free Electricity Session) the Solar was still used, and less was taken from the Grid. Now after the update, Solar seems to be disabled for the duration of the slot. Wasting Solar energy, again this worked fine before.
I am on Agile Export
• Before the update, I could set a force discharge to a certain FD SoC e.g. 30% to leave enough battery for the evening until the cheap slot again. This worked perfectly.
• Now after the FD SoC is reached it uses Grid import for the remainder of the slot, which could get expensive.