How to Reduce Boiler Pressure?

Boiler pressure if too high can be dangerous and lead to problems within your central heating system. The pressure gauge needs to be set just right.
Are you tired of fixing your boiler pressure? 

If you want your boiler to operate efficiently and safely, the pressure gauge needs to be set just right. Too high boiler pressure can be dangerous and lead to problems within your hot water and central heating system.

We have come up with this guide to help you understand why your boiler pressure is too high and what you can do about it. 

Why Does Boiler Pressure Matter?

Boiler pressure is determined by the balance between air and water within the machine, and this balance must be maintained for the boiler to be gas safe, which is vital for your safety and for the boiler to work effectively.

The boiler's pressure is created in its pipes and components, and too much pressure within the system can be dangerous. On the other hand, low pressure can also cause issues; find out what to do if this is the case in our guide.

It is a good idea to consult an engineer whether you need to reduce the boiler pressure or bring it back to a healthy level. An alternative to dealing with issues caused by high or low pressure might be getting a new boiler, which can be purchased at a fixed price instead of having an old boiler repaired.

How to reduce boiler pressure: 

A Guide to Reading Boiler Pressure

  • It would be ideal if the boiler could tell you when you need to adjust the pressure and then contact an engineer on your behalf, but unfortunately, that is not the case.

  • To determine if your combi boiler is working correctly, you should monitor the pressure gauge.

  • On most boilers, the gauge's colour and number make it easy to see when the boiler pressure reaches a dangerous level.

  • The boiler pressure gauge will be in the green section if the boiler is running between 1 bar and 1.5 bar.

  • Whenever the pressure from the water in the system reaches more than 2.5 bars, which is too high, and anything below 1 bar is too low.

  • Your heating system should automatically shut itself off if the boiler pressure gets too high or too low. Several new boiler models, such as the Worcester BOSCH 8000, will shut off automatically at a high pressure of three or four bars.

  • If your boiler has high pressure, it may simply be a sign that the system's water supply is under increased pressure.

  • However, there is a problem if your boiler pressure is too high, at around 3 bars, without any additional demand for hot water.

Causes of high boiler pressure

If your boiler pressure is consistently too high, something is wrong with your system. Here are some of the common causes of high boiler pressure:

A new boiler is needed

  • When it comes to boilers, the average lifespan is expected to be around 10 years. 

  • If this is the case, you might be better off purchasing a new boiler than trying to repair your old one.

  • Financial support is possible if you need a new boiler, but you must go through an authorised and regulated credit broker.

Typical Faults

  • Too much water or air pressure in your boiler can be caused by the expansion vessel, pressure release valve, or filling loop.

  • Sometimes, the boiler pressure rising to 3 bar.

  • Boilers should be checked by a safe gas engineer to ensure that your home has a reliable source of heat and hot water.

  • Most boilers with faulty valves of this kind can be easily repaired, and it does not have to be expensive.

How to fix if boiler pressure is too high:

  • If the issues with water pressure are not too challenging, you might be able to resolve them yourself.

  • If it concerns one of the valve controls as we mentioned, perhaps you can solve the problem by yourself. For example, your issue may be resolved by re-pressurising a filling loop, for instance.

  • To reduce boiler pressure caused by too much water, first you must make sure that this is the problem. Switch off the boiler and check its pressure gauge

  • The boiler pressure is too high if it exceeds 1.5 bars.

  • Water can be pressure released from a boiler, which can be fixed. To find how to release boiler pressure on your radiators, all you have to do is open the radiator key.

  • Using a pressure gauge, you can track when the excess water has come out of your boiler by opening the radiator valves a little bit. It is recommended to maintain the normal operating water level (NOWL) in the middle of the gauge glass.

  • To prevent surfaces from becoming moist when bleeding radiators, you should use towels or other floor coverings.

Boiler pressure too high: how to avoid it?

If you're able to get your boiler pressure back to normal, investigate why it happened in the first place. Review the suggestions below.

How to check the filling loop of your central heating system?

  • Two valves feed the system with water from the mains, entering the filling loop. The system lets in more water when both valves are open, which causes the pressure to rise. 

  • When the valves are accidentally left open, the leading cause of high pressure is the valves. 

  • To open, the handle must align with the pipe. 

  • If it does, it means it is turned by 90 degrees. Make sure that they are both closed - your system circulates its water and rarely needs topping up.

  • It is possible to connect the two valves in the filling loop with a length of hose rather than with permanent pipework.

  • This is because the water would be gushing out if the valves were open on a hose loop if the hose were not connected.

  • And what should boiler pressure be when heating is often varied between 1 to 1.5 bars. 

How full is my filling loop?

There is a possibility that someone responded to low pressure in the past (for example, after bleeding the radiators) by adding more water via the filling loop. As a result, people sometimes overfill it by mistake.

What to do if your expansion vessel is faulty?

Pressure is kept constant in the expansion vessel, preventing sudden changes. However, a damaged expansion vessel may lead to an increase in pressure. Make sure you have a professional inspect this and fix it - you can't do it yourself.

How does boiler cover work?

A boiler policy is essentially just boiler insurance. The process is so similar to that of home or auto insurance. As long as you pay a monthly fee and if something goes wrong with your boiler, you can call your provider, and they will send someone to fix the problem.

It's impossible to prevent a boiler from breaking down. But you can take steps to prevent the breakdown from negatively impacting your home and bank account.

Heating our homes with a boiler is essential for keeping us comfortable. However, it is only when they go wrong that we miss their work. Unfortunately, there is no easy or cheap way to fix a boiler that plays up, but it needs to be fixed immediately when it does.

Therefore, boiler insurance can be so important.

You'll feel more relaxed knowing you're protected from some of the worst costs associated with boiler repair. The cost of the callout will usually be covered by boiler insurance.

With our boiler insurance policies, you can ensure that your boiler is inspected at least once every year by a professional.

Concluding points.

An appliance like a boiler can be expensive to purchase or fix when something goes wrong. So, you would think boiler cover and peace of mind would make sense. In this blog, we considered all aspects of reducing boiler pressure and the importance of boiler insurance. 

Smart Covers’ boiler cover is an insurance policy that covers the interruptions that may leave you without hot water or heating, as well as damage caused by malfunctioning controls, parts, or leaking gas supply pipes. We are glad that we could assist you in deciding if the boiler insurance is worth getting covered.


Understanding why your boiler might be leaking water is crucial for home safety. Explore the five primary reasons behind boiler water leaks to identify and address potential issues promptly. Visit our comprehensive guide on why boilers leak water for essential insights into safeguarding your home's heating system. 

Understand the differences in energy sources, installation costs, operating expenses, efficiency, and maintenance requirements between electric and gas boilers. Explore our comprehensive guide comparing electric and gas boilers to make the right choice for your home. 

Discovering how to plumb a toilet waste pipe is a crucial aspect of home maintenance that demands attention to detail and precision. Our latest blog post offers a comprehensive guide to mastering this essential skill.