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Tier 1 · Gas

Vaillant boiler repair and servicing in London

The brand Londoners search for by name more than any other, and a common choice in flats and conversions.

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  • Gas Safe registered and fully insured
  • Diagnosed before it is quoted
  • Price agreed before work starts
  • Workmanship guaranteed

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About the brand

Vaillant boilers

Vaillant is a German manufacturer with a long history in the UK, and its ecoTEC range shows up constantly in London flats and converted properties, partly because the units are compact enough to fit the cupboard installations a conversion often forces. It is also the brand Londoners search for by name more than any other — usually because they already own one and want an engineer who actually knows it. Ninja Plumbers engineers see enough of them across the city that most faults are familiar before the cover even comes off.

The Vaillant range

Vaillant is a family-owned company based in Remscheid, Germany, and its group also owns Glow-worm and Saunier Duval. Its UK gas boilers sit under the ecoTEC name. The ecoTEC pro is the simpler, combi-only model. The ecoTEC plus comes as a combi, as a system boiler for homes with a pressurised cylinder, or as a heat-only model for an older open-vented system with a loft tank. The ecoTEC exclusive sits at the top. Vaillant is priced at the premium end of the mainstream. Older Vaillants still turn up regularly in London, especially non-condensing turboMAX units and early ecoMAX condensing boilers. Many can still be serviced and repaired, but they are a different conversation from a ten-year-old ecoTEC. Vaillant also makes aroTHERM heat pumps; this page is about the boilers.

What we see on Vaillant boilers

  • Expansion vessel failures presenting as pressure that will not hold
  • Ignition and flame-sensing faults on higher-hour ecoTEC units
  • Pump and pressure-sensor faults that stop the boiler firing at all
  • Hot water that turns lukewarm in hard-water parts of the city
  • Compact installations in cupboards where servicing access is tight

These are patterns Ninja Plumbers sees across the Vaillant installed base, not a diagnosis of your boiler. Faults are identified on site before anything is quoted.

Servicing a Vaillant

An ecoTEC needs a yearly service, and Vaillant’s warranty usually depends on it, along with registering the boiler after installation. Terms differ between models and installers, so check your warranty terms rather than assuming a headline length applies to yours. A good Vaillant service includes cleaning the condensate siphon and checking the pre-charge in the expansion vessel with the boiler side drained down. The vessel is one of the parts most likely to fail on these boilers, and finding a flat one at the service costs far less than a winter of topping up. Many London Vaillants live in a kitchen cupboard built snugly around them: clear it before the visit, and tell us if a shelf or door has to come out. In a flat, the boiler is normally the leaseholder’s responsibility, but a flue through communal parts may need the managing agent involved.

Repair or replace?

A Vaillant under about twelve years old is usually worth repairing. The parts that fail most — expansion vessel, pump, pressure sensor, diverter valve, fan — are ordinary repairs on an ecoTEC, not signs of a boiler at the end of its life. The line moves on an older unit when the main heat exchanger fails, or the control board goes on a boiler that has already had several repairs. Then we price the repair and a replacement side by side and tell you which we would choose. The turboMAX units are a different case. Being non-condensing, they burn noticeably more gas for the same heat, and a major repair on one keeps an inefficient appliance going. We would still fix a small fault to get you through a cold spell, then suggest planning the replacement for spring rather than waiting for the next breakdown.

What we do

Vaillant boiler work

Questions

Vaillant questions

My Vaillant keeps losing pressure. Is that the boiler or the system?
Either, and it is worth knowing which before spending. A leak on the pipework or radiators loses water you can sometimes find; a failed expansion vessel loses pressure with nothing visible anywhere. The vessel is a common failure at this age of unit and is a repair rather than a replacement.
What do F.22 and F.28 mean on my Vaillant?
On ecoTEC boilers, F.22 is the low water pressure code: if the gauge reads below about 1 bar, top it up with the filling loop as the user manual describes. F.28 means the boiler tried to light and could not, so check that gas is reaching the hob and, on a prepayment meter, that there is credit. If either code comes back after one reset, leave it and call.
ecoTEC pro or ecoTEC plus — which do I need?
For a combi in a flat or smaller house, the pro is the simpler and cheaper choice and does the job well. The plus also comes in system and heat-only versions, so it suits homes that keep a hot water cylinder or tanks in the loft. We look at the property and the incoming mains before recommending either.
Do you repair and service Vaillant boilers?
Yes. Gas work is carried out by Gas Safe registered engineers, which is the legal requirement for working on any gas boiler regardless of make.
Other brands

We work on every make

Something wrong with your Vaillant?

Send us the model and any fault code showing on the display, and we can often tell you what is likely wrong with it before an engineer sets off.

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