What are Valliant boilers?

Frank Finn Plumbing is a certified Vaillant boiler expert in London, specialising in Valliant boiler service and repair in London. All our technicians are experienced experts who vouch for the Vaillant brand as the right choice for a homeís heating. Being a market leader, Vaillant is one of the better boiler brands to buy. They are also exceptionally dependable and come with a 7-year warranty. Combi boilers are the most common types in the UK, especially in London.

The reason is they save space and donít require a hot water cylinder or storage tank. This is probably due to the little amount of space they take up and because they have no need for a hot water cylinder or a storage tank. Itís the best choice for buildings that require constant hot water, especially homeowners whoíd rather not rely on stored water in hot water cylinders. Safety and comfort are guaranteed in your home when the Vaillant boiler brand is installed.

Compared to other boiler models, this brand of boiler is very cost efficient when it comes to both energy and utility costs.


To get the most suitable Vaillant boiler for your hot water and central heating requirements, call certified Vaillant professionals, Frank Finn in London on 0208 408 0743.

How do you know your boiler has a fault?

Here are common error codes your Vaillant boiler may display:


Code F27: This indicates a frozen condensate pipe.

Code F22: This points out a popular boiler fault – low water pressure.

Code F75: This indicates your boilerís sensor is not aware the pump has started running. Itís a common problem seen in older boilers that have had magnetic filters fitted or that havenít been flushed in a while.

Code F28: A faulty ignition or gas not being supplied to the boiler can bring about this error code.

Code F29: This means a snuffed boiler flame.

Odd noises coming from your boiler

Strange banging, or whistling noises in the boiler – Air in the system is the usual suspect.

Issues with thermostat

Problems with thermostat – You are better of replacing your boiler’s thermostat when it begins giving false readings or erratically switching your heating off and on.

Boiler keeps turning off

Boiler keeps turning off – Usual culprits are a lack of water flow due to a closed valve, low water pressure, and air in the system or a problem with the thermostat or pump which are not circulating water in the system 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 heating or hot water – Tends to be as a result of a broken airlock or diaphragm, a broken motorised valve, low water level or a damaged thermostat.

Boiler leakages

Leaking boiler – A leaking gas boiler is safer switched off, and looked at by a Gas Safe registered engineer. Never attempt fixing your leaking boiler on your own unless you have the required training.

Blown out pilot light

Pilot light goes off – A broken thermocouple can cause this by stopping the gas supply into the boiler. A draught might have also blown out the pilot light or a build-up of deposit in the pilot light slot.

Falling pressure

Dropping pressure – If your pressure gauge shows “below 1”, there might be an issue caused by reasons ranging from; a water leak in the system, pressure relief valve needing replacing or radiators being recently bled.

Anytime you request our expert services

Reach us on

How can we fix your Vaillant boiler?

Fixing your boiler by yourself can be risky. For your safety, please call a professional Gas Safe engineer from Frank Finn for your Vaillant boiler repairs in London.

We can also carry out high-level maintenance work on your boiler if needed. 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;

  • Radiator bleeding.
  • Ridding your boiler system’s radiators of sludge by power flushing it
  • Radiators that aren’t heating up will get faulty or broken valves replaced.
  • 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 make sure fans are running fine.
  • We’ll check and verify all seals are still in place.
  • A flue gas analyser will be used (if necessary) to make sure your boiler is burning the correct mixture of air and gas.
  • 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.
  • Ensure there’s free flow throughout the condensate trap and pipe.
  • Checking the integrity of all safety devices is also an important part of our assessment.

I want to install a Vaillant boiler, what do I do?

Replacing a faulty boiler or installing a new one can be stressful, especially when you aren’t sure what model is best for your needs.

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.

This familiarity and expertise are why you should reach out to us at Frank Finn Plumbing on 0208 408 0743 for your Vaillant boiler installation in London.

At a very reasonable fee, our top engineers and plumbing specialists can anytime you need it provide speedy, quality service where you need it.

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