Baxi 800 series Fault Codes
The Baxi 800 is the brand's current flagship family — 800 Combi 2, System 2 and Heat 2 — launched in 2019 and sharing its platform with sister brands across the BDR Thermea group. It marks a change in Baxi's fault language: instead of the old single E-numbers, the 800 shows two-part codes such as E.00-.04 or E.02-.07, where the pair together identifies the fault family and the specific trigger. H-prefixed codes (H.01, H.02…) also appear for conditions the boiler treats as temporary blocks rather than hard lockouts. The upside of the new scheme is precision — the two-part codes distinguish causes the old E-codes lumped together. The practical rule: record both halves exactly, dots and dashes included, because E.01-.04 and E.02-.04 are different diagnoses. Each code below links through to its full page.
Where 800 series fault codes appear
The 800 has a modern backlit display showing status in normal running and the two-part code on a fault — E-prefixed for lockouts needing attention, H-prefixed for temporary blockings the boiler expects to clear itself. Photograph the display rather than trusting memory; the two-part format is easy to mis-transcribe.
Resetting a Baxi 800 series
Press the reset button and hold briefly; the boiler clears and retries. Low-pressure faults want a top-up to 1–1.5 bar via the filling loop first — the 800's display shows pressure directly. H-codes generally clear themselves when the underlying condition passes; an H-code that persists for hours behaves like a fault and deserves the same attention.
Common 800 series problems
The 800's early years have been solid; the codes owners actually meet are the condensing-boiler universals — low pressure, ignition faults with the winter condensate story, and occasional sensor codes — now expressed in the two-part format. As a current range with warranties up to 10 years registered, recurring faults belong with Baxi's warranty line, and the annual service keeps both boiler and cover healthy.
Most common 800 series fault codes
- E.00-.04 Baxi boilers display fault codes in two parts — the prefix and a suffix — and… Read more →
- E.02-.07 The E.02-.07 fault code means your Baxi boiler has detected that the system water… Read more →
- E.01-.04 The Baxi E.01–E.04 family covers a range of locking faults — meaning the boiler shuts… Read more →
- E.04-.00 The E.04-.00 fault code on Baxi boilers signals that the boiler's control board cannot… Read more →
- H.01-.00 The H.01 – .00 code appears when your Baxi boiler detects a temporary loss of… Read more →
- H.02-.02 The H.02-.02 code is a temporary blocking fault indicating that the boiler's printed… Read more →