Boiler Help

Here are some helpful videos to better explain what is meant by some of the more technical boiler jargon terms used by boiler installers.

Sometimes when your engineer talks to you using boiler jargon about your boiler and heating system, it may seem like a foreign language you don’t understand. We can help you translate most of the issues that you may come across so that if you encounter a problem with your boiler again, you will know exactly what your engineer is saying and have a background understanding of how to rectify the situation.

Below we have listed some of the more common phrases that you may hear, and we explain what they mean and what is actually happening in your hot water and heating system.

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Q: “Your expansion vessel has lost its pressure.”

What a boiler technician might say; “Your expansion vessel has lost its pressure.” What they mean: Expansion vessels are found in most boilers, especially combi boilers, and are needed to cope with the extra water created by expansion during the heating process. Read More

Q: “Your Boiler Needs a Service.”

Just like a car or other complex household appliances, regular servicing is essential to extend the life of your boiler and keep it running efficiently. Read More

Q: “Your Condensate Pipe is Frozen.”

Condensation is a normal by-product of a boiler and is made when the gas is burned to create heat. This condensation is discharged automatically into a drain either inside or outside the house. Read More

Q: “The Fan in Your Boiler Needs Replacing.”

Boilers produce waste gases which must be safely released. Your boiler contains the fan that pushes the waste gases through a pipe, known as a flue, to the outside of your home, where the gases are safely released into the air. Read More

Q: "How the Boiler Works?"

If you’ve ever thought of how your heating system boiler works, this is going to be an introduction to the domestic heating system. Read More

Q: “Your Time Switch is Faulty.”

Time switches turn the boiler on or off at the times you set. If the time switch fails, the boiler may not work. Read More

Q: "What is an A rated boiler?"

A rated boiler refers to the Seasonal Efficiency of Domestic Boilers in the UK (SEDBUK ) Boiler Efficiency Rating. Read More

Q: "Why is my boiler not firing?"

It’s important to talk to an expert boiler engineer before taking any action. Read More

Q: "Why a Boiler makes noise?"

Boilers make noise for many reasons. Boiler engineers often refer to the noise as ‘kettling’. They usually divide the causes for it into two groups, chemical and mechanical. Read More

Q: “Your Diverter Valve is Sticking.”

The diverter valve is a part inside the boiler that switches between hot water for your taps and the central heating. Valves can jam or become ‘sticky’, preventing them from working properly. Read More

Q: “Your Printed Circuit Board is Faulty.”

PCB is short for Printed Circuit Board. Modern boilers are controlled electronically and the PCB is the ‘brain’ of the boiler. Read More

Q: "How to bleed a radiator?"

To bleed a radiator, you will have to release basically pockets of air trapped in the central heating system that keeps it from functioning properly. Read More

Q: “Your Pilot Light Has Gone out or Isn’t Working Correctly.”

A pilot light is a small constant gas flame that ignites your boiler when heat or hot water is needed. Pilot lights are only found in older boilers. Read More

Q: “Your PRV is dripping.”

PRV is short for ‘Pressure Release Valve.’ This is a safety device, built into a boiler that activates if the water pressure rises to a level the boiler cannot cope with. Read More

Q: “I’m Gas Safe-Registered.”

The Gas Safe Register is the official list of gas engineers who are qualified to work safely and legally on gas appliances. Read More

Q: “You Have Poor Flow Rate From Your Taps.”

Flow rate is the term used to describe the rate at which water comes out of your taps or shower. A poor flow rate means that the flow of water from some or all of your taps or shower, will be low. Read More

Q: “You Have Sludge in Your System.”

Sludge is the material that has settled to the bottom of a heating system, usually your radiators. It will make your heating system run less efficiently and can lead to boiler parts failing. Read More

Q: “You Have Air in Your System.”

Heating systems should contain only water. Your system has air in it, which needs to be removed as it’s either causing a problem or threatens to. Read More

Q: “Your Radiators Need Bleeding.”

Bleeding is the term used for letting air out of a radiator and heating system. Bleeding a radiator involves opening a small valve at the top of the radiator to allow any trapped air to escape. Read More

Q: “Your Flow Switch Isn’t Working.”

Flow switches are a major part of a combi boiler and would be familiar to a competent installer. The flow switch’s job is to sense when you turn on a hot-water tap and the boiler. Read More

Q: “The Water Pressure Needs Topping up on Your System.”

Combi and system boilers and your heating system work under pressure. If the pressure drops below a certain level the boiler will not fire. Read More

Q: “You Should Have a Filter Installed on the System.”

Your boiler system will benefit from having a filter installed. A filter will help keep the water in the system as clean as possible. Read More

Q: “We’ll Need to Flush Your System Before Fitting the New Boiler.”

Your heating system should be thoroughly cleaned by flushing it with pressurized water in line with the boiler manufacturer’s instructions. This should always be done before installing a new boiler. Read More

Q: “You Should Upgrade Your Radiators with TRVs.”

TRV is short for Thermostatic Radiator Valve. This is an adjustable valve connected to each radiator that allows you to alter the temperature of each room by regulating the flow of hot water to each individual radiator. Read More

Q: “Would you Like Weather Compensation Control to Make Your System More Efficient?.”

Weather compensation control is an optional control available for modern boilers. It works by monitoring the temperature outside and using this information to help the boiler work as efficiently as possible. Read More

Q: “Would You Like to Have Wireless Controls?.”

Radio Frequency (RF), or wireless controls, pass information between the controls and the boiler without the need for wires. Read More

Q: “Have you Considered the Type of Control you Would like with Your Boiler?.”

You have a choice of what controls you can have fitted to help you manage your boiler. Better (more sophisticated) controls will give you greater control over your heating system and can make it more efficient. Read More

Q: “You Should Consider Changing Your Back Boiler as They are Really Inefficient.”

You have an old boiler, located behind a wall and fire front, that is inefficient and should be replaced. Read More

Q: “You Need to Upgrade From a Standard-efficiency Boiler to a High-efficiency Boiler.”

You have an old boiler that isn’t working efficiently. Recent changes in the law mean all new gas boilers fitted in the UK should be high-efficiency condensing models. Read More

Q: “This Boiler is Very Efficient and Has a Fantastic SEDBUK Rating.”

The boiler your installer is showing you is a very efficient model. SEDBUK stands for Seasonal Efficiency of Domestic Boilers in the UK. Read More

Q: “A Combi Boiler Won’t Meet Your Hot-Water Demands.”

A combi boiler will not be able to produce all the hot water you need. This means you will not get enough hot water out of all of your taps at the same time. Read More

Q: “You Might Benefit from Changing Your Open-vent System.”

An open-vent system may not be the best boiler system for you. Usually this is because you want to make changes to your home such as adding a loft conversion or freeing space currently needed for a cylinder (for example an airing cupboard). Read More

Q: “You Need a Combi Boiler, System Boiler or Open-vent Boiler.”

Your installer is recommending what sort of heating system best suits your house. There are three main types of boiler systems: Read More