Why Does My Boiler Keep Losing Pressure?

If you’ve ever wondered, “Why does my boiler keep losing pressure?” you’re not alone. Low boiler pressure is a common issue that many homeowners encounter, especially in the UK with the weather changes, and it can be frustrating to deal with.

Understanding the causes of low boiler pressure is the first step towards ensuring your heating system operates efficiently and effectively to keep your home or property warm and comfortable.

Find out the common reasons why your boiler keeps losing pressure and see our insights into how to diagnose and resolve your boiler problems here.

Low boiler pressure can be a recurring issue for many homeowners, but understanding the underlying causes is key to effectively address and resolve the problem. Some common reasons why your boiler may be losing pressure includes:

1. Leaking Pipework

One of the most frequent causes of low boiler pressure is a leak in the pipework or heating system. Even a small leak can lead to a gradual loss of pressure over time which can impact the efficiency of the boiler.

2. Bleeding Radiators

When air is trapped inside your heating system, it can cause a drop in boiler pressure. Bleeding your radiators to release trapped air is a simple fix for this issue. If you notice that certain radiators are cooler at the top than at the bottom, they likely need bleeding.

3. Faulty Pressure Relief Valve

The pressure relief valve is designed to release excess pressure from the boiler, so if it is malfunctioning or improperly set, it can cause consistent pressure loss in your boiler.

4. Expansion Vessel Problems

The expansion vessel is a crucial boiler component that absorbs the expansion of water as it heats up in the boiler system. If the vessel is damaged or has lost its charge it won’t perform properly, causing boiler pressure issues.

5. Water Loss

Over time, some boilers may lose water due to natural evaporation and is a more common issue in older boiler systems.

6. Boiler Corrosion and Rust

Internal corrosion within the boiler or heating system can result in rust and debris which can impact boiler pressure as rust particles can clog pipes and components, leading to pressure drops.

7. Faulty Boiler Seals and Valves

Defective seals, gaskets, or valves can allow water to escape from the boiler system, causing a loss of pressure.

8. Incorrect Installation

In some cases, low boiler pressure may be caused by incorrect installation. If the system was not properly installed or balanced, it can result in boiler pressure issues.

9. Cold Weather and Temperature Changes

Extreme weather conditions, such as sudden drops in temperature (cold snaps), can cause water in the pipes to freeze, resulting in pressure loss.

10. Boiler System Design

Inadequate boiler designs, such as undersized pipework or radiators, can lead to boiler pressure problems.

Addressing the specific cause of low boiler pressure is crucial to ensure your heating system operates efficiently and reliably. If you’re unsure about the root cause or are uncomfortable performing any troubleshooting yourself, it’s advisable to consult a qualified heating engineer or technician who can diagnose and resolve the issue effectively, such as a member of our team at Homecare Heating.

Our team can diagnose your boiler issue and let you know if you require a boiler replacement.

Regular maintenance and quick boiler repairs will help keep your boiler’s pressure healthy, ensuring your home remains is properly heated this winter.

Low boiler pressure itself is not dangerous; however, it can be a symptom of underlying issues in your heating system that could potentially lead to safety concerns and damage to the boiler.

When a boiler operates with low pressure it may struggle to provide heating which can result in a less comfortable home environment, especially during the colder winter months.

A reason why low boiler pressure is not very dangerous is because many modern boilers have safety features that can shut down the boiler if the pressure falls below a certain level. While this is designed to prevent damage to the boiler, it can leave you without heating and hot water when you may need them the most.

However, prolonged use of a boiler with low pressure can cause damage to the boiler, including the potential for overheating.

The biggest danger of low boiler pressure is the potential for a gas leak, and if you have a gas boiler, a drop in pressure could indicate a gas leak or other gas boiler problems. While not directly caused by low pressure, gas leaks are extremely dangerous as they can lead to the release of carbon monoxide, a toxic gas that is colourless and odourless.

Although low boiler pressure itself is not dangerous, it should be treated as a warning sign that something may be wrong with your heating system. Ignoring it can lead to discomfort, potential damage to your boiler, and, in the case of gas boilers, safety hazards.

Therefore, it’s important to investigate and address the root causes of low boiler pressure promptly to maintain the efficiency and safety of your heating system. If you’re unsure about how to do this, it’s advisable to consult a qualified heating engineer or technician for assistance.

The ideal boiler pressure typically falls within a specific range that will be indicated in your boiler manual, and it’s important to maintain it within these limits to ensure your boiler operates efficiently and safely.

In most heating systems, the ideal boiler pressure range is typically between 1.0 and 1.5 bar (14.5 to 21.7 psi) when the system is cold. However, this range can vary slightly depending on the type and model of your boiler, so consult your boiler’s manual or manufacturer’s recommendations for the specific pressure range they recommend.

If the pressure is below this range, we recommend trying to identify the issue and calling our team at Homecare Heating for a boiler repair and check.

If your boiler keeps losing pressure, it’s essential to address the issue, as some problems you can solve yourself. First check for visible leaks around radiators, valves, or the boiler itself, and if you spot any, they will need to be repaired promptly to maintain the system’s pressure by a professional.

Some boiler pressure fixes that you can solve yourself are by bleeding your radiators and topping up the boiler with water.

To bleed your radiators to release trapped air, follow the below steps:

• Turn off your heating system.
• Use a radiator key or a flathead screwdriver to open the bleed valve at the top of each radiator.
• As air escapes, you’ll hear a hissing sound. Once water starts to flow steadily, close the valve.
• Repeat this process for all radiators in your home.

To fix lost water, fill the loop in the boiler with water following the below steps:

• Turn off the boiler.
• Locate the filling loop, which is usually a flexible hose with valves at both ends.
• Open both valves to allow water to enter the system. Keep an eye on the pressure gauge and stop filling when it reaches the recommended range (usually between 1.0 and 1.5 bar).
• Close the valves and turn the boiler back on.

If your boiler is not working properly, phone us today on 0151 203 3771, or alternatively fill out our contact form and a member of the team will get back in touch.