SPH 3000–6000TL BL-UP / SPH 4000–10000TL3 BH-UP hybrid (Error 2xx–6xx codes)
Growatt Error 604 error code
EPS/backup output voltage is below specification.
Likely causes
- Overload or large motor start on the EPS output
- EPS output wiring too thin or too long, causing volt drop
- EPS output disabled or misconfigured
- Inverter output-stage fault
Checks to run, in order
- 1Measure EPS output voltage with a true-RMS meter under load
- 2Check the connected backup load against the EPS rating
- 3Inspect EPS wiring size and length
- 4Confirm EPS is enabled and set to the correct voltage/frequency
Fixes
- Reduce the backup load and retry
- Correct the EPS wiring gauge or length
- Restart the inverter and re-measure the EPS voltage
When to escalate
If EPS voltage stays low with no load connected, ask Growatt support to check the EPS output stage.
Fix it with the right tools
Check the system around the fault before replacing parts: load, battery bank, PV string and commissioning settings. If you need a second opinion, send the code and your inverter model to our team.
Before you open the inverter
- Isolate both the AC and DC sides, then confirm the display is dead before touching terminals.
- Use insulated tools and one hand where possible. DC arcs do not self-extinguish like AC.
- If you see burnt terminals, swollen cells, leaking electrolyte or a burning smell, stop and escalate instead of resetting the fault.
Questions installers ask
What does Growatt Error 604 mean?
EPS/backup output voltage is below specification.
How do I fix Growatt Error 604?
Reduce the backup load and retry Correct the EPS wiring gauge or length Restart the inverter and re-measure the EPS voltage
When should I escalate Growatt Error 604?
If EPS voltage stays low with no load connected, ask Growatt support to check the EPS output stage.
Can I reset Growatt Error 604 myself?
Only after isolating the AC and DC sides and running the checks above. If Growatt Error 604 returns immediately, stop resetting it and escalate; a repeating fault usually points to a real circuit, battery or hardware problem.
Which models show Growatt Error 604?
Growatt Error 604 is documented for SPH 3000–6000TL BL-UP / SPH 4000–10000TL3 BH-UP hybrid (Error 2xx–6xx codes). Confirm the code on your own unit's display or manual before ordering parts.
More Growatt error codes
- Growatt 01Fan is locked (displayed as F01 on the SPF ES Lite).
- Growatt 02Internal component temperature is over 100 °C (F02 on the ES Lite).
- Growatt 03Battery is over-charged / battery voltage is too high (F03 on the ES Lite).
- Growatt 04Battery voltage low.
- Growatt 05Output is short-circuited (F05 on the ES Lite).
- Growatt 06Output voltage is too high. The manual groups 06/58 as 'output abnormal' — inverter voltage above 150 Vac or below 40 Vac.
Guidance reviewed 17 October 2026 by the Mishka Energy installer team. Error codes vary by brand, model family and firmware; confirm against the manufacturer manual.
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