13 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
Replaced by: Flexicom cx
The fault code is already on your display
Note it down before pressing reset — resetting clears the code immediately. How to read fault codes →
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 |
Tap any card for details
Your boiler's main internal computer has lost touch with the display panel on the front, meaning you cannot control your heating or hot water.
Your boiler has detected an electrical fault with the internal sensor that monitors the temperature of the water flowing to your radiators, causing the system to shut down for safety.
Your boiler's hot water sensor has developed an electrical fault, meaning it can no longer accurately monitor the temperature of the water in your cylinder.
Your boiler has stopped working because there is not enough water pressure in the system to operate safely.
Your boiler has shut down because the exhaust fumes have become too hot, which is a safety measure to prevent damage to the internal components.
Your boiler's computer memory has been wiped or is mismatched, meaning it no longer recognizes which model it is supposed to be.
Your boiler has detected a blockage in the drainage system or an issue with the flue, causing it to shut down to prevent water or exhaust gases from backing up.
Your boiler is trying to start up but cannot successfully light the gas flame needed to heat your water.
Your boiler has detected that the internal fan responsible for safely venting exhaust gases is not working correctly, so it has shut itself down to prevent unsafe operation.
Your boiler is trying to stay on, but the flame is repeatedly going out, meaning it cannot provide you with any heating or hot water.
Your boiler has detected that the water pressure inside your heating system is either too low or too high for it to operate safely.
Your boiler is struggling to manage its gas supply, which means it cannot safely light or stay running to heat your home or water.
Your boiler has detected a general internal communication failure between its main control components, causing it to stop operating to protect the system.
Not faults — these are normal operating states. Tap to expand.
BoilerFaultCodes