H Faults

H Codes are reset by turning the boiler off then on by the user control. Codes can flash alternatively

H3 Jumper Links - Further Information
H4 Flue thermister fault attempt reset. Check flue is not obstructed, check for air in system – bleed rads . If when bleeding radiators problems getting water out of upstairs radiators. Refer to installer, if installer confirms system OK then fault could be faulty flue thermistor. - Engineer visit required
H9 Overheat - Further Information
HA Overheat - Further Information
HB Reset button fault, attempt reset. If still Hb - Engineer visit required. Note this fault can sometimes be described as H6
HE
 PCB Error, attempt reset. If still HE - Engineer visit required
HF
 Flame Detection - Further Information
HN
 Hn indicates "Cross Polarity" (Live & Neutral power supply to boiler is crossed) User should contact Installer or Electrician
H1 Control thermistor problem - attempt reset. If still H1 engineer visit required
H- Electrical fault - boiler has been wired up to an electrical generator which is not suitable for use with the Icos boiler, User should contact Installer or Electrician