Warmflow Fault Codes

Select a fault code to see its meaning, common causes and how to fix it.

E01 The E01 code on a Warmflow boiler signals a burner lockout — a built-in safety shutdown that occurs when the boiler… Read more →
E02 The E02 code means your Warmflow boiler has detected that its internal water temperature has climbed to an unsafe level… Read more →
E03 The E03 code appears on Warmflow boilers when the flue thermofuse has tripped. The thermofuse is a dedicated safety… Read more →
E04 The Warmflow E04 fault code carries two different meanings depending on which product range your boiler belongs to. On… Read more →
E05 The E05 code on a Warmflow boiler signals a problem with the boiler flow NTC (Negative Temperature Coefficient)… Read more →
E06 The E06 code on a Warmflow boiler indicates a fault with the Domestic Hot Water (DHW) Flow NTC Temperature Sensor. This… Read more →
E11 The E11 code on a Warmflow Agentis combination boiler indicates that the internal thermal store or hot water tank has… Read more →
E12 The E12 code appears on the LCD display of the Warmflow Agentis Combination Boiler and points to a problem with the… Read more →
E15 The E15 fault code on Warmflow Agentis combination boilers indicates a problem with the central heating return NTC… Read more →
E16 The E16 code on a Warmflow boiler signals that the control board has detected a problem with the flue fan. The fan's… Read more →
E22 The E22 code on a Warmflow boiler carries two distinct meanings depending on which model you own. On GS-Series gas… Read more →
E31 The E31 code appears on Warmflow Agentis Series boilers when the main control board can no longer communicate properly… Read more →
E35 The E35 fault code on a Warmflow boiler indicates that the control board has lost confidence in the ionisation… Read more →
E42 The E42 code appears on certain Warmflow Agentis combination boiler models and, based on the fault numbering pattern… Read more →
E46 The E46 code appears on Warmflow boilers — including the Agentis series — when the control board detects a problem with… Read more →
E48 The E48 code appears on Warmflow Agentis series boilers when the internal pressure sensor detects that the water… Read more →
H20 The H20 code means your Warmflow boiler has detected that the water pressure in the central heating circuit has dropped… Read more →