Vaillant boilers explained

In Surbiton, Frank Finn Plumbing is recognised as a certified Vaillant expert. 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. They are also exceptionally dependable and come with a 7-year warranty. In Surbiton, in the UK, the Combi boiler model is the most common in households.

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. This is because installation consumes very little space and it doesnít require a storage tank or a hot water cylinder attachment. If you need a steady and instant supply of hot water in your home without having to rely on stored water from hot water cylinders, Combi boilers are the perfect choice. The safety and comfort of your home are assured when using a Vaillant boiler.

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


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

When will you require assistance with your boiler?

Below are the usual error codes seen on a Vaillant boiler display;


Code F27: This shows a condensate pipe is likely frozen.

Code F22: This indicates the most common boiler fault of all, low water pressure.

Code F75: This indicates the pump is running, but the boilerís sensor is not aware. A common problem in older boilers that have never been flushed or have had magnetic filters fitted.

Code F28: This is seen when thereís no gas supplied to the boiler, or thereís a faulty ignition.

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

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

No heat or hot water

Shortage of hot water or no heating – can be due to a faulty thermostat or motorised valve, a broken diaphragm or airlock, a broken valve or poor water level.

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. The pilot light being blown out or a build-up in the pilot light compartment are also probable causes.

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 will we help fix 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 repairs in Surbiton.

Our experts can also help with maintaining your boiler. We recommend boiler maintenance checks be done at least yearly to ensure its optimal performance and your home’s safety.


Our engineers can also confirm if all is well with key components of your boiler by performing the following checks;

  • Having your radiator bled.
  • Power flushing the boiler’s system to ensure no sludge is in the radiators.
  • To fix non-heating radiators, we can replace faulty or broken valves.
  • If the radiators in a larger home need balancing and fine-tuning, we can provide that.
  • We are also available to perform the following necessary safety checks on your boiler
  • We’ll verify that all fans are properly working.
  • We’ll make sure all seals are intact.
  • If necessary, we’ll use a flue gas analyser to verify your boiler is burning the appropriate combination of gas and air.
  • We’ll ensure no electrical connection is out of place or malfunctioning.
  • We’ll check to make sure all electrodes are properly working.
  • Ensure there’s free flow throughout the condensate trap and pipe.
  • Check all safety devices and make sure they are active.

Who can help in purchasing and installing a Vaillant boiler?

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 Surbiton.

We have top men and women on the job that can offer quick, quality service around the clock and 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.