Glow-worm 38cxi Fault codes & diagnostics

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

Combi Natural Gas 38 kW 2007-2013 Discontinued

GC Number 47-019-03

Replaced by: Flexicom cx

Download the Glow-worm 38cxi manual The official installation & service manual (PDF) — the exact document these fault codes were verified against. PDF

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Versions & GC numbers

Which version do you have?

The GC number on your boiler's data badge identifies the exact appliance and production years, as recorded in the UK Product Characteristics Database.

GC number	Appliance (register name)	Produced
47-019-03	Ultracom 38cxi	2007–2013

Appliance names and production years are taken from the UK Product Characteristics Database (the SAP/SEDBUK register). Where a GC number is also printed in this model's own manufacturer manual, both sources were checked to agree.

Fault codes

All 2 documented codes

Tap any card for details

Parts commonly replaced

Ignition electrode
Gas valve
Printed Circuit Board

Related codes

Status & diagnostic codes

37 operating states & engineer diagnostics

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

S.00 Status Your boiler is currently in standby mode because it has not been asked to provide any heating or hot water at this moment. S.01 Status Your boiler is currently performing a standard safety check of its internal fan before it starts the ignition process. S.02 Status Your boiler is currently preparing itself by circulating water before it fires up, which is a normal part of its startup process. S.03 Status Your boiler is currently struggling to light the flame needed to produce heat and hot water. S.04 Status Your boiler is operating normally and is currently firing up to heat your water or radiators. S.05 Status Your boiler is currently running its internal pump to safely circulate water after heating, but it is taking longer than expected to complete this cycle. S.06 Status Your boiler is currently running its internal cooling fan to safely clear out residual gases after a heating cycle, which is a normal part of its shutdown process. S.07 Status Your boiler is currently cooling down after a cycle and is momentarily running its internal water pump to safely move heat away from the burner. S.08 Status Your boiler is perfectly fine; it is currently taking a brief, mandatory pause between heating cycles to prevent excessive wear on its internal parts. S.10 Status Your boiler is currently operating normally as it detects you have turned on a hot water tap. S.11 Status The boiler is checking that its internal air extraction system is working correctly before it attempts to light the burner. S.13 Status Your boiler is trying to start but failing to light the flame properly, which means it cannot provide heat or hot water. S.14 Status Your boiler is currently operating normally and is actively heating the water for your radiators or taps. S.15 Status Your boiler is currently running its internal cooling cycle to move excess heat away from the system, which is a normal part of its operation. S.16 Status Your boiler is currently running its internal cooling fan to safely clear out gases after the burner has turned off, which is a normal part of the shutdown process. S.17 Status Your boiler is currently running its internal pump to safely move leftover heat away from the system, which is a normal part of the cooling-down process. S.20 Status Your boiler is currently just running a routine internal check on its hot water system and this is a normal operating status rather than a fault. S.21 Status Your boiler is currently performing a routine safety check by clearing its internal chambers before attempting to ignite. S.22 Status Your boiler is currently running a standard self-check process to prepare the water pump before the burner lights, which is a normal part of its startup routine. S.23 Status Your boiler is failing to start because it cannot detect a flame after trying to ignite. S.24 Status Your boiler is currently operating normally as it is in the process of heating water for your radiators or taps. S.25 Status Your boiler is struggling to circulate water properly or clear gases after a heating cycle, preventing it from starting up correctly. S.26 Status Your boiler is currently running its internal cooling fan longer than usual to safely remove leftover gases after the burner has turned off. S.27 Status Your boiler is currently running its internal pump to safely circulate leftover heat after the burners have turned off, which is a normal part of its cooling process. S.28 Status Your boiler is temporarily waiting between heating cycles to protect itself from excessive wear and tear. S.30 Status Your boiler is currently idle because it is not receiving a signal from your thermostat or timer to turn the heating on. S.31 Status Your boiler is currently set to summer mode, which means it is only heating your water and will not provide central heating. S.32 Status Your boiler is temporarily pausing because it has detected an inconsistency in its fan speed, which it does to protect the system while it stabilizes. S.34 Status Your boiler has detected that the temperature inside the unit is very low and has automatically turned on its internal heater to prevent the pipes from freezing. S.36 Status Your boiler is currently idle because it is not receiving a signal from your thermostat or timer to turn the heating on. S.42 Status Your boiler has detected an issue with an add-on device or control unit that is preventing it from starting up safely. S.53 Status Your boiler is temporarily pausing because the water leaving the heater is much hotter than the water returning, suggesting a circulation blockage. S.54 Status Your boiler has detected that there is either not enough water in the system or the water is struggling to circulate properly, so it has paused itself to prevent damage. S.76 Status Your boiler is temporarily pausing its operation to double-check that the water pressure inside the system is at the correct level before it safely fires up again. S.96 Status Your boiler is currently performing a routine internal safety check on its water temperature sensors and has temporarily paused heating and hot water while it completes this self-test. S.97 Status Your boiler is currently performing a routine internal safety check on its water pressure and has temporarily paused heating or hot water until the test is finished. S.98 Status Your boiler is currently performing a routine internal self-check to ensure temperature sensors are working correctly before it allows the heating or hot water to turn on.