Viessmann boiler fault codes
On a Viessmann the control unit decides what the display shows, not the boiler name, so the first thing to find is not "Vitodens 100-W" but the type designation printed after it. It is on the type plate, which on a wall-hung Vitodens sits on the top panel beside the flue connection (a second copy of the QR label is meant to be stuck inside the front of the operating instructions), and it reads WB1A, WB1B, WB1C, B1HA, B1HC, B1HF and so on for the 100-W; B1LA to B1LG for the 111-W; BPJD, B0HA or B0KA for the 050-W; B2HA, B2HB or B2HF for the 200-W. That designation picks the fault table. The two-character generations (WB1B through B1HC, 111-W B1LA to B1LD, 050-W BPJD) share one table with small differences: WB1B editions have no E3 row, the storage-combi 111-W has no 52/5A flow-sensor rows, the 2016-on B1HC adds 0A, 0C, A3 and b7. The 2020-on units with the black-and-white arrow-key programming unit (100-W B1HF/B1KF, B1HG and B1GA, 111-W B1LF/B1LG, and the 050-W B0HA from 2023) use a completely different numeric table — F.14, F.62, F.980 — in which a bare "E 3" on the home screen is the holiday programme, not the safety-chain fault of the same name. The Vitotronic-controlled 200-W, 222-F and 242-F print a sentence plus a code, report a failed ignition as EE rather than F4, and carry Lambda Pro combustion-controller calibration codes (E1, E2, E7, E8, EA, Eb) that no 100-W has. Viessmann distinguish a burner that is "blocked" (it waits for the condition to clear and restarts by itself) from a burner "in a fault state" (locked out until you reset it), and their instruction on resets is quoted here rather than softened: if faults are not rectified they can have life threatening consequences; do not reset the burner several times in quick succession; notify your heating contractor if a fault recurs. Viessmann publish no permitted number of resets. Their UK Fault Code Checker covers around a dozen entries; the tables that follow are from the installation and service instructions for each unit, which is the only place the full lists exist.
Where the code shows on a Viessmann
Vitodens 100 WB1A and 100-W WB1A (2004 to 2008): a two-character code flashes with the fault symbol and the Reset key lights up. WB1B, WB1C, B1HA/B1KA and 111-W B1LA/B1LB (2008 to 2016): the code flashes with a wrench symbol on the small LCD between the two rotary selectors; the system-pressure reading flashes instead when pressure is low. B1HC/B1KC and 111-W B1LD (2016 to 2020): a touch panel; the wrench flashes with the code, and when "R" also appears the burner is locked out. 050-W BPJD (2018 to 2023): a lower-priority fault shows the code steady with the warning triangle flashing, a higher-priority one flashes both. B1HF/B1KF, B1HG, B1GA and 111-W B1LF/B1LG (2020 on) and 050-W B0HA (2023 on): the same black-and-white programming unit on all of them shows a warning triangle with the fault code; a locked-out burner shows a "CL" glyph and the triangle flashes; the number itself is reached with the up and down arrows, and the last five faults are kept under "b.4". Viessmann write the numbers as F.14, F.62, F.980 in the instructions. Vitotronic 100 HC1B / 200 HO1B (200-W B2HA/B2HB, 222-F B2TA, 242-F B2UA): a red fault indicator, a plain-text description and the code beside it ("Outside t sens 18"), with a fault history under the menu. E3-platform 200-W B2HF and 222-F B2TF: F.xxx codes on a 3.5-inch black-and-white screen or a 7-inch colour touchscreen. Whatever the unit, write down the number; the symbol is the same for every fault.
How to reset a Viessmann
There is no single Viessmann reset, and the wrong one changes a setting rather than clearing a lockout. WB1A: press the illuminated Reset key. WB1B, WB1C, B1HA/B1KA and 111-W B1LA/B1LB: turn the heating rotary selector to the RESET position for less than two seconds, then back into the control range. B1HC/B1KC and 111-W B1LD: touch "R" for approximately two seconds. 050-W BPJD: press MODE and OK simultaneously; the display shows three dashes while it resets. B1HF/B1KF, B1HG, B1GA, 111-W B1LF/B1LG and 050-W B0HA: use the arrows to show the fault number, note it, then hold the up and down arrows together for approximately four seconds until a rotating bar appears; Viessmann add that a reset is only possible after the burner has cooled down. Vitotronic 100 HC1B / 200 HO1B: press reset button R on the control unit. E3-platform 200-W B2HF/B2KF and 222-F B2TF: a menu action called Unlock — select Unlock on the home screen and confirm with OK, or Active messages, Burner fault, Unlock. Only codes whose table row says "Burner in a fault state" need a reset at all; a "Burner blocked" code restarts itself when the cause is gone, and a "Constant" or "Continuous operation" code means the boiler is still running on a fallback. On every unit Viessmann say the same thing: do not reset repeatedly, and if it comes back, call your heating contractor.
Most common Viessmann faults
The Viessmann codes people look up most.
- F4Stop — call an engineerNo flame signal was detected during burner start on any two-character Vitodens, so the burner has locked out. Reset once; if it returns, call a Gas Safe engineer.
- F.74Get it checkedSystem pressure too low on a 2020-on Vitodens with the numeric display. The burner and pump stop until the pressure is back. Viessmann tell the householder to top up below 1.0 bar.
- F.65Stop — call an engineerNo flame signal at burner start on a 2020-on Vitodens — the numeric table's equivalent of F4. Burner locked out. Check the gas is on, reset once; if it returns, call a Gas Safe engineer.
- EAStop — call an engineerA Lambda Pro combustion-controller code on Vitotronic-controlled 200-W, 222-F and 242-F boilers: the ionisation current during calibration was outside the permissible range or implausibly different from last time. Lockout; engineer.
Every Viessmann fault code
56 published codes. Filtering happens in the page — every one is in the HTML.
Showing 56 of 56 codes
Viessmann models
Codes can differ between generations. Check yours.
Guides that help with Viessmann faults
Boiler fault codes explained: what they actually tell you
Codes look like diagnoses and are not. Understanding which family a code belongs to turns a meaningless number into a genuinely useful starting point.Read the guideHow to repressurise a boiler
The five-minute job that resolves more no-heating calls than any other. Here is how to do it properly, and how to tell when topping up is the wrong answer.Read the guideWhat a Gas Safe engineer actually checks in a boiler service
Most people pay for this once a year and stand in another room while it happens. Here is what should be going on, which test cannot be faked, and how to tell a real service from twenty minutes and an invoice.Read the guideWhat to do when your condensate pipe freezes
The single most common winter boiler fault, and one of the few you can genuinely fix yourself in fifteen minutes with a kettle and some patience.Read the guide
Looking for Viessmann’s own support? www.viessmann.co.uk. We are not affiliated with Viessmann.