Medium
7 03 on Ariston E-Combi One

Your boiler is having trouble communicating with one of its internal temperature sensors, which may cause your heating or hot water to work inconsistently.

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

Zone 3 outgoing sensor defective

From this model's manual
Verified against the Ariston/Ariston E Combi One 24 installation & service manual, page 39.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the boiler is unable to read the temperature data from the specific sensor responsible for your third heating zone. The most common cause is a failure of the internal thermistor (NTC sensor) or a loose connection in the wiring harness that links the sensor to the main control board.

Engineer required

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

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Related fault codes

7 01View →7 02View →7 04View →

All 53 fault codes on the E-Combi One

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

1 011 031 041 051 061 071 091 101 121 141 161 181 P11 P21 P31 P42 053 013 023 033 043 053 063 073 P94 114 124 135 015 025 045 P15 P25 P36 106 127 017 027 117 127 137 227 237 5010121314108591INSUFFICIENT WATERSafety Shut-off

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