Sime Planet Super 4 WM Fault codes & diagnostics

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

Combi Natural Gas 1996-2006 Discontinued
GC Number 47-719-16
Download the Sime Planet Super 4 WM 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 Super 4 WM faults?
The top 6 problems in plain English — with causes, DIY checks and repair costs.
Fault codes

All 5 documented codes

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LED / flash-pattern codes
Digital codes
Red LED after flow switch

Your boiler has stopped working because water is not moving through the system correctly, causing it to shut down to prevent overheating.

High DIY-safe £120-£350

What to check first

  1. Check that your boiler pressure is between 1.0 and 1.5 bar
  2. Ensure all radiator valves and isolation valves are fully open
  3. Try resetting the boiler using the selector dial

Parts commonly replaced

  • Circulation Pump
  • Water Flow Switch
  • Overheat Thermostat

Related codes

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

Your boiler has failed to light the gas and has locked itself for safety, which is why it is currently not providing heating or hot water.

High DIY-safe £100-£250

What to check first

  1. Check that your gas meter is turned on and you have credit if using a pre-payment meter
  2. Check if other gas appliances in your home, like a hob, are working correctly
  3. Hold the reset button for a few seconds to see if the boiler restarts
  4. If the boiler is in a cold location, check that the white plastic condensate pipe outside isn't frozen

Parts commonly replaced

  • Ignition Electrode
  • Gas Valve
  • Flame Sensing Probe
  • PCB

Related codes

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

19 operating states & engineer diagnostics

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

15 Diagnostic Your boiler is currently indicating that it has reached the pre-set temperature target for your home and is temporarily pausing its heating cycle. 51 Diagnostic Your boiler has detected that the water inside the system is getting too cold and has activated its built-in safety feature to prevent the pipes from freezing. 52 Diagnostic Your boiler is struggling to accurately detect the outdoor or system temperature required to switch between heating and hot water modes. 53 Diagnostic Your boiler's control settings are not properly configured, which is preventing the system from correctly communicating with your home's temperature sensor. 54 Diagnostic Your boiler is struggling to accurately read the outdoor 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 heating system has become too hot and has automatically shut down to prevent damage. 56 Diagnostic Your boiler is struggling to control how quickly the water temperature rises, which may lead to the system shutting down to prevent overheating. 57 Diagnostic Your boiler is currently recalibrating its internal settings to adjust for your heating system's specific requirements. 58 Diagnostic Your boiler is currently recalibrating its startup settings to improve efficiency, so it is temporarily pausing normal operation. 59 Diagnostic Your boiler is struggling to heat the water at the expected speed, likely due to a poor connection or an internal sensor failing to register the temperature increase. 60 Diagnostic Your boiler is currently in a pre-programmed standby or 'off' mode, likely because a timer setting has been reached or the internal clock is preventing it from firing. 61 Diagnostic Your boiler is struggling to reach or maintain the correct temperature for your hot water, which means your taps or shower may not get as hot as they should be. 62 Diagnostic Your boiler is struggling to detect that it has enough water inside to operate, often because the filling valve has been left open or the internal pressure is dropping. 63 Diagnostic Your boiler's settings have been accidentally locked by the internal software, preventing it from functioning normally until the programming is reset. 64 Diagnostic Your boiler has detected an issue with an external control or connection, such as a faulty room thermostat or a loose link wire, which is preventing it from firing up correctly. 65 Diagnostic Your boiler is receiving an conflicting signal from an external accessory, such as a weather sensor or an external timer, which is preventing it from firing normally. 66 Diagnostic Your boiler is struggling to read the temperature from the outdoor sensor, which is causing it to adjust your heating system incorrectly. 69 Diagnostic Your boiler is currently performing a routine self-cleaning process to ensure the hot water system remains hygienic. Orange LED on Status Your boiler is simply in standby mode and is waiting for a command from your thermostat or hot water tap to start heating.