Medium
116 on Ariston Clas HE R

Your boiler has detected that the external thermostat connected to your underfloor heating system has triggered a safety shut-off or is disconnected, meaning the heating will not run until this is resolved.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

floor thermostat contact open

Shared across the Clas HE range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

118View →

All 45 fault codes on the Clas HE R

Seeing a different code? Every code this model can display, in one place.

1 011 021 031 041 051 061 071 081 101 121 141 181 P11 P21 P32 022 042 072 083 013 023 033 043 053 063 074 075 015 025 045 P15 P25 P36 046 107 017 027 037 047 057 067 07E00E99

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