What are Valliant boilers?

When it comes to Vaillant boilers, Frank Finn Plumbing is recognised as the experts in London-South. Our technicians who are all experts in their respective fields will always recommend the Vaillant brand for your homeís central heating. Being a market leader, Vaillant is one of the better boiler brands to buy. Asides from being efficiently built, Vaillant systems come with a 7-year warranty. In London-South, in the UK, the Combi boiler model is the most common in households.

The reason is they save space and donít require a hot water cylinder or storage tank. The reason for this is they donít need a lot of space for installation, and they donít need a hot water cylinder or storage tank fixtures. Itís the best choice for homes that need a steady supply of heated water, especially those that would rather not use hot water cylinders. The Vaillant boiler, when put in place, assures the comfort and safety of your home.

Because of their superb efficiency, Vaillant saves you a great deal in terms of energy costs and utility costs when compared to lesser models.


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

How do you know your boiler needs help?

Listed below are common Fault codes displayed on a boiler system;


Code F27: This means a condensate pipe is frozen.

Code F22: This indicates the most common boiler fault of all, 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 broken ignition or no gas supplied to the boiler can cause this error code.

Code F29: This means a snuffed boiler flame.

Odd noises coming from your boiler

Boiler emitting strange noises – Air getting in your boiler system is the usual cause.

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 won’t stay on – Can be brought on by air in the system or malfunctioning pump, poor water pressure or poor water flow thanks to a closed valve or issues with the thermostat.

Radiator not getting hot

Radiator won’t get hot – You might find that your radiator isn’t getting hot or that only the bottom section is heating up and this can be caused by sludge or air build-up, or unequal 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

Boiler leakages – Never try fixing a leaking gas boiler if you don’t have the necessary training and qualification, instead, call on a Gas Safe registered technician to look at your dripping boiler.

Blown out pilot light

Switched off pilot light – can be brought on by a damaged thermocouple blocking gas supply to the boiler, or your building has no gas supply. A snuffed out pilot light or accumulated filth in the compartment for the pilot light can also be a cause.

Falling pressure

Insufficient pressure – When the pressure gauge drops to “below 1”, this can be due to maybe the pressure relief valve needing replacing, or a water leak in the system, or that the radiators were bled not long ago.

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How will we help fix your Vaillant boiler?

Fixing your boiler by yourself is unsafe. Instead of you risking fixing your boiler without proper training, and bringing on an avoidable accident, we recommend you call for a Frank Finn professional Gas Safe engineer to help with your Vaillant boiler repairs in London-South.

We can also carry out high-level maintenance work on your boiler if needed. We recommend boiler maintenance checks be done at least yearly to ensure its optimal performance and your home’s safety.


Our engineers will also check and if your boiler needs important components replaced by;

  • Radiator bleeding.
  • Getting rid of sludge inside your boiler system’s radiators by power flushing it
  • To fix non-heating radiators, we can replace faulty or broken valves.
  • Larger homes can have their radiators balanced and fine-tuned by us.
  • We’ll also carry out the following safety checks on your boiler;
  • We’ll make sure fans are running fine.
  • We’ll ensure no seals have been broken.
  • If need be, a flue gas analyser will be used to ensure the boiler is not burning the wrong mixture of gas and air.
  • We’ll ensure no electrical connection is out of place or malfunctioning.
  • Verify the working condition of all electrodes.
  • Check the free flow of the condensate trap and pipe to make sure there is no blockage in the system.
  • Check all safety devices and make sure they are active.

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

Deciding what model to install for your first boiler or replacing a defective one can be hectic, especially when you don’t know enough to decide what model will best suit 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.

Our familiarity with these boilers and our experience is why you should get in touch with us at Frank Finn Plumbing by dialling 0208 408 0743 for your Vaillant boiler installation in London-South.

Our specially trained and certified technicians are available around the clock to provide you fast, efficient and quality service at a pocket-friendly price.

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