BoilerFaultCodesWhat the manual says
Manufacturer manualTemperature measured by return sensor greater than flow temperature SENSOR/CONNECTION PROBLEM Check that the sensors are positioned the correct way around Check that the flow sensor is in the correct position Check the return temperature in the boiler Check the operation of the sensors
From this model's manual
Verified against the Baxi/Baxi Bm Baxi B Basic System 2 600 800 Assure 500 Isim installation & service manual, page 50.
Engineer required
This is a high severity fault. Stop using the boiler and call 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 E.01 .12: 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.
All 66 fault codes on the Assure System
Seeing a different code? Every code this model can display, in one place.
101213A.00.28A.00.29A.00.34A.02.06A.02.18A.02.36A.02.37A.02.45A.02.46A.02.48A.02.49A.02.54A.02.55A.02.76E.00 .04E.00 .05E.00 .16E.00 .17E.00 .20E.00 .21E.01 .04E.01 .17E.01 .20E.02 .13E.02 .17E.02 .35E.02 .39E.02 .47E.04 .01E.04 .02E.04 .08E.04 .12E.04 .13E.04 .17E.04 .18E.04 .23E.04 .29E.04 .54E.04 .254E.04.03E.04.10H.00.42H.00.81H.01 .14H.01.00H.01.05H.01.08H.01.18H.01.21H.02 .00H.02 .02H.02 .03H.02 .04H.02 .05H.02 .09H.02 .10H.02 .70H.02.07H.03 .00H.03 .05H.03 .54H.03.02