"Reset the unit" is the first instruction Bosch support gives for most issues. Three reset levels.
Level 1: error code reset (Greentherm and Greenstar)
For any displayed error code, press the Reset button on the controller. The unit attempts to restart and clear the fault.
Level 2: power cycle
- Turn off the unit at the controller
- Turn off the breaker
- Wait 30 seconds
- Restore power
- Turn unit back on
Level 3: service menu / factory reset
Requires Bosch installer password. Don't attempt without installer guidance.
Tronic POU mini-tank reset
Tronic POU mini-tanks have a high-temp cutoff (ECO) similar to standard electric tank water heaters. To reset:
- Unplug the unit
- Remove the access panel (usually held by 1-2 screws)
- Locate the red ECO reset button on the thermostat
- Press the button firmly until you feel a click
- Replace panel; plug back in
If the ECO trips again within hours, the thermostat or heating element has failed.
Tronic Heat 3000 electric tankless reset
If the unit fault-locks (typically after multiple breaker trips):
- Verify electrical service is adequate (US12 needs 200A; US9 needs 150A)
- Turn off breaker, wait 30 seconds, restore
- If repeated trips: electrical service is undersized; needs professional electrical evaluation
When reset doesn't fix things
Three resets in a row with immediate re-throw = real underlying fault. Stop cycling. Work through the diagnostic walkthrough on the specific error code page.
Bottom line
Start with Level 1 controller reset. Tronic POU: ECO red button. Tronic Heat electric: verify electrical service. For tankless and combi, if the code re-throws, go to the specific error code page.