Ariston Clas overheat codes: the 1-series group and what it points at

What Does Error 1-series Mean?

Ariston organises Clas fault codes into groups by their leading digit, and the 1-series belongs to the primary water circuit. An overheat entry within that group therefore comes pre-labelled as a water-side condition, which is a genuinely useful piece of structure that most manufacturers do not offer. Applies to: Ariston Clas gas boilers whose fault codes are grouped by leading digit in the Ariston user documentation The grouping described here is the one Ariston uses in Clas user documentation. Ariston sells other ranges with their own conventions, and appliances sold under related brand names are documented separately. Match the code to the manual issued with your own boiler before applying the grouping. Owner-safe checks: Record all three digits of the code exactly, since the leading digit and the pair that follow it do different jobs. | Read the system pressure gauge while the system is cold and write the figure down. | Feel each radiator after a heating attempt and map which heat, which do not, and where the cold begins on the panel. Qualified technician: Anything that restores flow through a sealed heating circuit, from a new circulator to a chemical clean, is Gas Safe registered work when it involves the appliance itself. | A boiler making boiling or knocking sounds should be left off rather than run while waiting, because those episodes deposit scale on the exchanger surface.