Common Vaillant codes we clear daily
F.28
Average reply under 10 minutes. No obligation.
Vaillant builds some of the most reliable boilers in the UK — the ecoTEC plus is practically the default boiler of the London loft conversion. But every design has its patterns, and after thousands of Vaillant callouts across the capital as part of our wider London-wide boiler repair service, ours are predictable: pressure-related F22 lockouts (often a slow leak or a tired expansion vessel rather than the boiler itself), F28 and F29 ignition failures as electrodes age, and F75 pump or sensor faults on units that have run hard through a few London winters. Hard water plays a part too — limescale shortens the life of heat exchangers and sensors across the whole city, which is why an annual boiler service is worth the money.
The good news: Vaillant parts are plentiful and well-documented, which is why our first-visit fix rate on Vaillant boilers is one of the highest of any brand we service. Our engineers carry the common ecoTEC parts — electrodes, sensors, expansion vessel kits, diverter components — in the van.
F.22
Repressurise to 1.5 bar via the filling loop. If it drops again within days, there’s a leak — book a trace and repair.
F.28
F.29
F.75
F.61 / F.62
Showing a different code? Call 020 3000 0000 and read it to us — we’ll tell you what it means over the phone, free.
Full guides: Vaillant F22 explained · Vaillant F28 explained
ecoTEC plus
ecoTEC exclusive
ecoFIT pure
ecoFIT sustain
aroTHERM (heat pump servicing)
Thermocompact
If your Vaillant is over 12 years old and facing a major repair, we’ll give you the honest repair-vs-replace numbers on site — see our new boiler installation options.
F22 repressurise + leak trace
Ignition electrode replacement (F28)
“F28 on a Sunday morning. Engineer arrived within the hour, new electrodes fitted from the van, running by lunch.”
“F22 every week for a month. They found the actual leak under the floor instead of just topping up the pressure like the last company.”
— HORNSEY
