Protherm error codes
Find the meaning of Protherm fault, warning and status codes, with model context, documented causes, safe checks and links to available manufacturer guidance.
24documented codes
1products and models
1product categories
About Protherm error codes
An error code is a diagnostic clue, not a complete repair diagnosis. Protherm may reuse similar-looking codes across different products, model generations or regions, so always confirm the complete code and exact model before following instructions or ordering parts.
This profile connects every indexed Protherm code to its dedicated explanation page. Each page is structured around the search intent: a quick meaning, symptoms, likely causes, safe troubleshooting, reset guidance, applicable products and the point at which professional help is appropriate. Records marked as verified include the manufacturer or another authoritative technical source.
Start with the code shown on the display, then narrow the result by product or model. Do not assume that a reset has repaired the underlying fault. If a code returns, the product is unsafe, or diagnosis requires internal electrical, gas, refrigerant or moving components, stop and use an authorised technician.
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Popular Protherm codes
ErrProtherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens Err error code – Control-panel communication errorCommunication between the operating panel and boiler electronics has failed.F.707Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.707 error code – Control-panel communication lostCommunication between the boiler electronics and control unit has failed.F.77Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.77 error code – Air/flue damper faultThe accessory module has not received the required feedback from the air or flue damper system.F.74Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.74 error code – Water-pressure sensor signal too highThe water-pressure sensor signal is above its valid electrical range.F.73Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.73 error code – Water-pressure sensor signal too lowThe water-pressure sensor signal is below its valid electrical range.F.70Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.70 error code – Invalid appliance code DSNThe electronics and display identifiers do not match.F.67Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.67 error code – Electronics or flame-signal faultThe boiler receives an implausible flame signal.F.65Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.65 error code – Electronics temperature faultThe boiler electronics have become too hot.
Protherm product groups
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Showing 1–24 of 24
ErrProtherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens Err error code – Control-panel communication errorCommunication between the operating panel and boiler electronics has failed.F.00Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.00 error code – Flow temperature sensor circuit openThe flow temperature sensor signal is interrupted.F.10Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.10 error code – Flow temperature sensor short circuitThe flow temperature sensor circuit is shorted.F.20Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.20 error code – Safety temperature limiter operatedThe safety temperature limiter has shut the boiler down because temperature became excessive.F.22Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.22 error code – Insufficient water pressureThe boiler has made a safety shutdown because the heating-water pressure is below 0.3 bar.F.27Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.27 error code – False flame signalThe electronics detect a flame signal while the gas valve should be closed.F.28Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.28 error code – Ignition unsuccessfulThe burner did not ignite during the start sequence.F.29Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.29 error code – Flame lost during operationThe boiler could not relight after the flame was lost during operation.F.32Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.32 error code – Fan speed outside toleranceThe measured fan speed differs too far from the required speed.F.37Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.37 error code – Emergency operation: minimum fan speed increasedThe boiler has raised its minimum fan speed while operating in an emergency mode.F.42Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.42 error code – Coding resistor faultThe appliance cannot recognise a valid coding-resistor value.F.49Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.49 error code – eBUS communication faultThe boiler detects an electrical fault on the eBUS connection.F.50Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.50 error code – Flue-pressure switch faultThe flue-pressure switch reports an unsafe exhaust or condensate condition.F.61Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.61 error code – Gas valve control faultThe electronics cannot control the gas valve correctly.F.62Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.62 error code – Gas valve shut-off delay faultThe gas-valve or flame signal does not shut down within the permitted time.F.63Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.63 error code – EEPROM faultThe boiler electronics report a memory fault.F.64Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.64 error code – ADC faultThe electronics report an analogue measurement fault.F.65Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.65 error code – Electronics temperature faultThe boiler electronics have become too hot.F.67Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.67 error code – Electronics or flame-signal faultThe boiler receives an implausible flame signal.F.70Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.70 error code – Invalid appliance code DSNThe electronics and display identifiers do not match.F.707Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.707 error code – Control-panel communication lostCommunication between the boiler electronics and control unit has failed.F.73Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.73 error code – Water-pressure sensor signal too lowThe water-pressure sensor signal is below its valid electrical range.F.74Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.74 error code – Water-pressure sensor signal too highThe water-pressure sensor signal is above its valid electrical range.F.77Protherm · Bear Condens floor-standing gas boiler · EuropeProtherm Bear Condens F.77 error code – Air/flue damper faultThe accessory module has not received the required feedback from the air or flue damper system.