• Gas safe approved
  • Trusted since 1982
  • East Anglia’s largest heating company
  • One fixed price

Do I need to top up pressure in my Boiler?

How to top up boiler pressure

Do I Need to top up the pressure in my boiler cover

Our Gasway Engineers advise that you should be checking your boiler pressure a few times a year. This ensures that everything is working as intended.

However, heating systems can seem to be pretty complicated. This tends to prevent people from checking this regularly.

In this guide, we are going to teach you how to maintain your boiler pressure.

Read on to find out exactly how.

What is Boiler Pressure?

what is boiler pressure

Boiler pressure is determined by the volume of water in a system, and the level of heat. It's important that this is balanced.

If the pressure is too high it can put strain on components which could cause permanent damage. If the pressure is low it may mean that your system is not running efficiently which could cause you to spend more on your bills each month.

What pressure level should my boiler be at?

Pressure gauges can be located on different parts on the system. System and Combi Boilers typically have the gauge located somewhere on the main unit.

Pressure is measured in bars, which is based on average pressure at sea level.
Generally, unless advised otherwise your heating system should be at around one bar when the unit is cold.

As discussed earlier pressure can be affected by water volume and heat, so typically you will see a rise in bar when the system is switched on.

However, if it rises above 2.5 bar this could be an indication of a fault. Or an early warning sign of one developing.

2.5 bar is the kind of pressure that large mining vehicles produce within their engine!

How often should I check my boiler pressure?

How often should I check my boiler pressure

We would advise checking your boiler pressure at least four times a year.

The best practice for this would be to input a date in your calendar every three months.

Not only will this allow your boiler to run at maximum efficiency more often throughout the year. If you do find a fault you can quickly get in touch with Gasway and decrease the likelihood of further damage to your system.

If you have checked your system and found that the pressure is below one bar, then it's time to top it up.

How to top up your boiler pressure

how to top up your boiler pressure

First, you will need to locate the filling loop, typically this is located alongside or below your system. 

If you cannot locate the loop, you may need to consult the manual or jump on our live chat and ask where it may be located.

Second, you will need to make sure that your system is cold and that your boiler is switched off.

On either side of the loop, there will be a lever, these are used to control the amount of water in the system. The more water in the system the more pressure.

It's very important that you keep an eye on the pressure gauge for the next step as if it gets too high or too low it can damage the system.

Thirdly, you will want to slowly turn either of these levers watching the pressure gauge closely as you do.
You will need to open both taps to balance out the pressure.

Once you have hit between, 1 and 1.5 bar then you will want to close the levers. Make sure these levers are fully closed as otherwise, pressure will continue to rise in the system.

Once this is complete it is safe to turn your system back on.

Should you ever accidentally overfill your system please get in touch with Gasway immediately.

What causes boiler pressure to drop?

There is a natural drop in pressure that occurs throughout the year, due to changes in temperature and some minor system inefficiency.

However, should you find that pressure is dropping a lot between top-ups then it is likely to be because of a leak.

Investigate your house for signs of dampness around pipes and radiators, if you do not find anything it may be worth getting in touch with Gasway to organise a service.

Sometimes leaks can occur inside of the boiler, Only a Gas Certified engineer should open your boiler, should you suspect a fault.

Can I Repressurise my boiler myself?

We would advise checking the manual for your system before you undertake this operation, as there are a few systems available that are not built to be manually repressurised.

However, on the whole, it is a normal part of maintaining the system. It should be done a few times a year to ensure your boiler has a long life and runs efficiently.

If you are at all worried about, any component or operation of your boiler then it is a good idea to get in touch with an expert.

Jump on our live chat, or get in touch with us today if you have any worries or questions.

If you want to learn more about your heating system and how to save energy on your bills we have a whole heap of guides available here.

Sam Teal Website Profile

Sam Teal - Marketing Manager: Do I need to top up the pressure in my boiler? (18th May 2022)

Sam is a seasoned writer, blending expertise in marketing, psychology, and emerging technologies.

With a keen understanding of consumer behaviour, Sam strives to make the heating industry greener and more sustainable. His diverse portfolio includes articles spanning multiple industries, including entertainment, board games, tech and of course the heating industry.

With a passion for change and innovation, Sam is one of many industry experts at Gasway Services LTD.

LinkedIn Instagram