VVaillant logo

Vaillant ecoTEC pro Fault Codes

The Vaillant ecoTEC pro is the ecoTEC plus's mid-market sibling — a combi-only range sharing the same platform, controls and F-code fault language, trimmed of some of the plus's refinements (smaller outputs, simpler modulation, no system/open-vent variants). For fault-finding purposes that shared platform is the headline: the pro's codes mean exactly what they mean on the plus, and the same diagnostic paths apply. The pro sold in large numbers to landlords and developers, so many owners inherit one without documentation. The essentials: faults show as F.xx codes on the digital display, most lockouts clear with the flame-cross reset button, F.22 means pressure (fix it yourself in five minutes), and the ignition pair F.28/F.29 covers most winter breakdowns. Each code below links to the full diagnosis page.

Where ecoTEC pro fault codes appear

The ecoTEC pro carries the same style of backlit display as the plus: temperature and status in normal running, "F." plus a number on a fault. Record the exact code — the F-series is precise, and adjacent numbers are different faults with different fixes.

Resetting a Vaillant ecoTEC pro

Press the reset button (crossed-out flame symbol) for about a second and the boiler retries. For F.22, top the system up to 1–1.5 bar via the filling loop first. A code that returns after one reset is a diagnosis, not bad luck — look it up and act on it rather than cycling the reset.

Common ecoTEC pro problems

The pro shares the plus's fault profile: F.75 pump/pressure-sensor, F.22 pressure loss, F.28/F.29 ignition, and F.27. Being combi-only and often installed in rentals, the pro's commonest real-world story is simple neglect — unserviced boilers with sludged filters throwing pressure and circulation codes. An annual service and clean system water prevent most of what appears on this page.

Most common ecoTEC pro fault codes

Last reviewed 25 August 2026.

Find a Gas Safe engineer

✓ Your boiler details: Vaillant ecoTEC pro — one step done already.

We pass your details to up to 3 vetted local engineers. No payment is taken here.

Can't find your boiler or fault code?

Tell us what you need — we'll help, and we can put you in touch with a Gas Safe registered engineer.

Get in touch →