Vaillant boilers

In London-South-West, Frank Finn Plumbing is recognised as a certified Vaillant expert. Our expert technicians often recommend Vaillant boilers for homes when a replacement boiler is required. The Vaillant brand is a market leader and is arguably the best brand of boiler to buy. Asides from being efficiently built, Vaillant systems come with a 7-year warranty. In the UK, especially in London-South-West, Combi boilers are the most common boiler model.

The reason is they save space and donít require a hot water cylinder or storage tank. The reason is they save space and donít require a hot water cylinder or storage tank. If you need instant hot water in your home, instead of relying on stored water in hot water cylinders, Combi boilers are the perfect choice for you. The Vaillant boiler, when put in place, assures the comfort and safety of your home.

In terms of energy costs, they save you a great deal on utility costs compared to lesser models, because of their excellent efficiency.


To ensure you get the best Vaillant model for all your heating needs, we strongly recommend contacting us, Frank Finn certified Vaillant professionals in London-South-West on 0208 408 0743.

How do you know your boiler needs help?

Listed below are common error codes a Vaillant boiler might display:


Code F27: This warns of a frozen condensate pipe.

Code F22: This indicates a commonplace boiler fault – low water pressure.

Code F75: This means your boilerís sensor is unaware the boilerís pump has started running. Usually, occurs in older boilers that have had magnetic filters fitted or that have never been flushed.

Code F28: A lack of gas supply to the boiler or a defective ignition can bring about this error code.

Code F29: This means a snuffed boiler flame.

Odd noises coming from your boiler

Odd noises coming from your boiler – The usual culprit is air in the boiler system.

Issues with thermostat

Issues with thermostat – it’s advisable to get a new thermostat when your boiler’s thermostat begins flipping your heating on and off or displays inaccurate readings.

Boiler keeps turning off

Boiler switching off incessantly – Can be due to low water pressure, or thermostat problems, poor water flow due to a closed valve, air in the system or the pump not functioning properly.

Radiator not getting hot

Radiator not heating up – This is usually caused by sludge or air build-up, or uneven distribution of heat.

No heat or hot water

No heat or hot water – Can be caused by a broken diaphragm or airlock, a failed motorised valve, a problem with the thermostat or low water levels.

Boiler leakages

Leakages from the boiler – Do not attempt fixing a leaking gas boiler yourself unless you’re appropriately qualified, instead, summon a Gas Safe registered engineer to check on your leakage.

Blown out pilot light

Blown out pilot light – A damaged thermocouple might be stopping the gas supply, or you might not be getting any gas supply into your house. A snuffed out pilot light or accumulated filth in the compartment for the pilot light can also be a cause.

Falling pressure

Losing pressure – If your pressure gauge indicates “below 1”, the issue might be caused by either a water leak in the system or the pressure relief valve needing replacing or that the radiators were recently bled.

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How to maintain your Vaillant boiler?

It’s not safe to fix your boiler on your own. Do not risk fixing your boiler yourself if you are not a certified expert, instead, reach out to a professional Gas Safe engineer from Frank Finn to assist with your Vaillant boiler service & repairs in London-South-West.

Maintenance work on your boiler is another service our experts offer. In an effort to ensure you enjoy your Vaillant boiler for as long as possible, we recommend you have a maintenance service done on your boiler at least once every year to keep it safe and efficient.


If it is necessary, our engineer will also check the following key components of your boiler to determine if they need repair or replacement;

  • Having your radiator bled.
  • Remove all sludge from the boiler’s radiators by power flushing.
  • If your radiator isn’t heating up, we can replace faulty or broken valves.
  • Another service we provide is balancing and fine-tuning of radiators in more complex homes.
  • We are also available to perform the following necessary safety checks on your boiler
  • We’ll ensure no fans are malfunctioning.
  • We’ll ensure no seals have been broken.
  • Using a flue gas analyser (where necessary), we’ll ensure your boiler is burning the right mixture of gas and air.
  • We’ll ensure all electrical connections are in the proper order and in good working condition.
  • Check all electrodes and ensure they are properly working.
  • Make sure the condensate trap and pipe has a free flow.
  • Checking the integrity of all safety devices is also an important part of our assessment.

What if I want to install a new Vaillant boiler system in my home?

Installing a new Vaillant boiler or replacing a faulty one can be stressful, especially if you are having difficulty deciding what model of boiler will be best to upgrade to.

In our years of experience at Frank Finn, we have had cause to deal with every design of Vaillant boiler and have come to know them intimately.

Because of our intimate knowledge, contact us at Frank Finn Plumbing by calling 0208 408 0743 for your Vaillant boiler installation in London-South-West.

We have highly trained and certified plumbing engineers who will deliver an efficient and quality service that’ll satisfy your boiler installation needs any time it’s required.

If you want to get your boiler serviced by a company that does the job the right way, contact Frank Finn now.