March 16, 2023


Boiler Overheating – Causes, Sings, and How to Fix It

Boiler Overheating

Boiler overheating is always a serious problem, no matter why it occurs. Modern units can recognise when the temperature is too high, triggering a safety feature that shuts down the boiler. Unfortunately, older boilers do not have that same comfort, and if not fixed in time, they can explode.

In case you are concerned about your boiler, read on to find out more about the signs of overheating, causes, and ways to fix it.

Causes of Boiler Overheating

Blockage in the System

If your boiler makes any unusual sounds, it could be due to a blockage in the system, either a physical blockage or an air blockage. In addition, if you notice that your boiler is not heating up correctly, there may be a problem with the system that requires an inspection.

Low Water Levels

Boiler leaks can result in low water levels. If the pressure gauge reads less than 1, check the pressure. It usually requires re-pressurisation by a professional. Sometimes low water levels occur because of the boiler shutting itself down, a result of possible closed valves, broken pump, or air in the system. In any case, it is essential to have a check-up as soon as possible.

Broken Thermostat

Every boiler contains a thermostat which is responsible for regulating the water temperature. Overheating can occur when the thermostat breaks, causing the water temperature to rise above acceptable levels. If you are in this situation, make sure you do not use the boiler and call a heating engineer.

Blocked Pipes

Just like other types of blockages in a heating system, pipe blockages can also cause problems.The cause of blokage may be air obstruction or physical barriers such as rust, sludge, coolant leaks, low coolant levels, and other similar issues. When the pipes are block, the entire system cannot function correctly, and this can result in the overheating.

Faulty Pump

The function of the water pump in a heating system is to circulate water throughout the entire system. If the pump breaks, the hot water will stay stuck in the boiler, therefore causes overheating boiler. Usually, when a pump is broken, there is no way to fix it, so a new one is required.

Build-up of Limescale

The limescale build-up is another big issue. Built around the heat exchanger, it restricts the water flow, leading the boiler to overheat. As the heat exchanger heats the cooler water before its circulation, if it is not working properly, it leads the boiler to overheat.

Signs of Boiler Overheating

Strange Noises

You might hear a few types of sounds, but the most common ones are by limescale buildup or a blockage in the system. Limescale build-up causes kettling sounds, which sound like the whistle of a kettle.

Leaking Water

If your boiler is leaking water, it indicates that it has deteriorated to a point where it requires replacement. Since water heaters are designed to be airtight, any leakage is problematic and can cause significant disruption around the house if not promptly addressed. Therefore, it’s crucial to turn off the water and seek the assistance of a professional without delay.

Strange Odours

This is the major sign of overheated boiler. The presence of an unusual smell in your water is likely due to bacterial growth in the tank. Although rust and corrosion can facilitate the growth of bacteria, failure to heat the water to an adequate temperature can also create an ideal environment for it. In most cases, draining and treating the water should effectively resolve the issue, but occasionally replacing the water heater is the only viable solution.

Increased Energy Bills

Higher energy bills might be a sign the water heater is not as efficient as it used to be. Water minerals build up around the water heater, resulting in sediment, which reduces its energy efficiency.

Insufficient Heating

If the boiler temperature too high, but cannot deliver it as per the thermostat temperature, there might be build-up in the tank or issues due to the thermostat’s short circuits. This can be generated by a range of issues: low pressure, faulty valves, broken airlocks or system diaphragms, or even broken thermostat.

How to Fix Overheating Boiler

Check the water level

Water level is the first sign of a boiler overheating, locate the pressure gauge and check the pressure. If the position is between 1 and 2 bars, everything is ok. Everything below or above that, and you have an issue. If it is below one, your boiler will shut down, and you will be without hot water. If it is above two bars, the system will not be able to hold the pressure and will fail.

Clean the Pipes

Whenever stuck pipes occur, your boiler needs a power flush, a cleansing process that will remove rust and limescale from your central heating system.

Replace Faulty Components

Boilers malfunction when their components, such as pipes and connections, become rusty, corroded, or broken. Additionally, motorized valves can deteriorate over time, causing them to turn on or off spontaneously. The best way to prevent such issues and extend the lifespan of your boiler is to check it regularly and replace faulty parts as soon as possible.

Consult a Professional

Any time you notice an issue with your boiler, turn off the water and the boiler. After that, call a professional expert to fix the problem. Just make sure you hire someone with the right qualifications as you look to solve problems.

The Dangers of Ignoring Overheating Boiler

Boiler overheating may result in prolonged periods without hot water. However, being proactive and addressing any warning signs can help you save money, avoid inconvenience, and prevent potential damage to your home, such as water leaks or an explosion.

Importance of Regular Maintenance

Boilers, like any appliance, wear down with time. However, regular maintenance will keep the boiler in its best condition possible, extending its lifespan. There will no danger from carbon monoxide, plus you will keep your energy bill down to a minimum.

If you need any help relate to boiler problems don’t hesitate to call TBIS. our experts will help you in getting the most efficient home heating.  You can also set up a new boiler installation schedule with our licensed professionals.

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