H Faults
| H Codes are reset by turning the boiler off then on by the user control. Codes can flash alternatively |  |
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Flow thermister fault, attempt reset if still H1 - Engineer visit required. | |
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Return thermister fault, attempt reset. If still H2 - Engineer visit required. | |
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DHW Thermister fault, attempt reset. If still H3 - Engineer visit required. | |
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H4 on Esprit HE , check flue is not blocked then treat H4 as per H9 faults then engineer visit required if fault persists. | |
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Jumper Links - Links not inserted into the boiler control board - Engineer visit required. | |
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Overheat - Further Information | |
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Overheat - Further Information | |
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Reset button fault, attempt reset. If still Hb - Engineer visit required. Note this fault can sometimes be described as H6. Reset button fault can be caused by the button stuck in, this can sometimes be unstuck by the user. | |
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PCB Error, attempt reset. If still HE - Engineer visit required | |
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Flame Detection - Further Information | |
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Hn indicates "Cross Polarity" (Live & Neutral power supply to boiler is crossed) User should contact Installer or Electrician |
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Electrical fault - boiler has been wired up to an electrical generator which is not suitable for use with the Isar boiler, User should contact Installers or Electrician |