Sime Planet Dewy BFR Fault codes & diagnostics

5 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.

Heat Only Natural Gas 1995-2008 Discontinued
GC Numbers 41-283-0341-283-11
Download the Sime Planet Dewy BFR manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

This boiler uses LED flash patterns

Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →

Just want the most common Sime Planet Dewy BFR faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 5 documented codes

Tap any card for details

LED / flash-pattern codes
LED flashing after fan

Your boiler has identified a problem with the fan that should be clearing out exhaust fumes, preventing it from starting up safely.

High Engineer only £180-350

Parts commonly replaced

  • Fan assembly
  • Fan wiring harness
  • Main PCB

Related codes

Full explanation for LED flashing after fan
Digital codes
Red LED after flow switch

Your boiler has stopped working because water isn't moving through the system correctly, causing it to overheat or fail to detect flow.

High DIY-safe £120-350

What to check first

  1. Check that the boiler pressure is between 1.0 and 1.5 bar on the gauge
  2. Ensure all radiator valves and isolation valves under the boiler are fully open
  3. Try resetting the boiler by turning the selector switch to the reset position and back

Parts commonly replaced

  • Circulation pump
  • Water flow switch
  • Limit thermostat

Related codes

Full explanation for Red LED after flow switch
Red LED on (solid)

Your boiler has tried to light but failed to detect a flame, causing it to shut down for safety.

High DIY-safe £90-250

What to check first

  1. Check if other gas appliances, like a hob, are working to confirm gas supply is active
  2. Ensure your gas meter has credit if you use a prepay meter
  3. Press and hold the reset button for a few seconds to see if the boiler restarts

Parts commonly replaced

  • Ignition electrode
  • Flame sensing probe
  • Gas valve
  • Ignition lead

Related codes

Full explanation for Red LED on (solid)
Status & diagnostic codes

18 operating states & engineer diagnostics

Not faults — these are normal operating states. Tap to expand.

51 Diagnostic Your boiler is simply protecting itself from freezing by temporarily warming its internal components while in standby mode. 52 Diagnostic Your boiler is struggling to automatically detect whether it should be in heating mode or summer hot-water-only mode due to a sensor signal error. 53 Diagnostic Your boiler's internal settings have become misaligned, preventing it from correctly communicating with your home's temperature controls. 54 Diagnostic Your boiler is struggling to accurately read the room temperature, which may cause your heating to turn on or off at the wrong times. 55 Diagnostic Your boiler has detected that the water inside the system is becoming dangerously hot and has shut itself down to prevent damage. 56 Diagnostic Your boiler is temporarily slowing down its heating process because it has detected that the water temperature is rising too quickly, likely due to a flow issue. 57 Diagnostic Your boiler is currently recalibrating its internal settings to adjust to your home's heating system requirements. 58 Diagnostic Your boiler is currently adjusting its internal startup settings and is not reporting a functional error, but rather confirming a configuration state. 59 Diagnostic Your boiler is struggling to heat your radiators at the expected speed, likely due to a poor connection or an internal sensor reading that something is wrong with the heat flow. 60 Diagnostic Your boiler is currently in a setup or configuration mode rather than a fault state, meaning it is waiting for a timer instruction to be programmed correctly. 61 Diagnostic Your boiler has detected that the internal settings for your hot water temperature are lower than they should be, likely due to a minor sensor error or control board glitch. 62 Diagnostic Your boiler is struggling to detect the demand for hot water, which means it may fail to heat the water when you turn on a tap. 63 Diagnostic Your boiler has entered a diagnostic information mode that shows settings on the display but does not indicate a system fault or breakdown. 64 Diagnostic Your boiler is receiving an conflicting signal from an external accessory, such as a timer or thermostat, preventing it from starting up correctly. 65 Diagnostic Your boiler is receiving a signal from an external accessory, such as a smart thermostat or weather sensor, that is preventing it from firing up. 66 Diagnostic Your boiler is struggling to read the temperature from an external sensor, which is preventing it from heating your home correctly. 69 Diagnostic Your boiler is currently running a scheduled high-temperature cycle to ensure the water inside your hot water tank remains hygienic and free from bacteria. Orange LED on Status Your boiler is simply in standby mode and is working correctly, waiting for a request for heating or hot water.