What the manual says
Manufacturer manualDevice priority error
Shared across the 800 System 2 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.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register →
Boiler cover options
Avoid the next call-out bill
A cover plan would handle faults like A.02.46: no call-out fees, no surprise bills.
Approved partner
Get a quote →
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Affiliate links. We may earn a commission at no extra cost to you.
Related fault codes
All 75 fault codes on the 800 System 2
Seeing a different code? Every code this model can display, in one place.
254A.00.34A.02.06A.02.18A.02.36A.02.37A.02.45A.02.48A.02.49A.02.54A.02.55A.02.76E.00 .04E.00 .05E.00 .06E.00 .07E.00 .16E.00 .17E.00.20E.00.21E.01.04E.01.12E.01.17E.01.20E.02.13E.02.15E.02.17E.02.35E.02.47E.04.00E.04.01E.04.02E.04.03E.04.07E.04.08E.04.09E.04.10E.04.11E.04.12E.04.13E.04.14E.04.15E.04.17E.04.18E.04.19E.04.20E.04.21E.04.23E.04.24E.04.54H.00.42H.01 .00H.01 .05H.01 .08H.01 .14H.01 .18H.01 .21H.02 .00H.02 .02H.02 .03H.02 .04H.02 .05H.02 .07H.02 .09H.02 .10H.02 .12H.02 .38H.02 .70H.03 .00H.03 .01H.03 .02H.03 .05H.03 .17H.03 .54
Related guides you might find useful
Radiator not heating up
One cold radiator is usually a stuck valve pin or trapped air.
Read →Hot water works but heating does not
On a combi it is usually the diverter valve. On a system boiler, the motorised valve.
Read →No hot water but heating works
Almost always a stuck diverter valve on a combi.
Read →