plumber installing a boiler

What To Do If Your Boiler Pressure Is Too Low

Nov-2019 / < 1 min read

Reading Time: < 1 minute

What To Do If Your Boiler Pressure Is Too Low

  • Home
  • New gas boilers are environmentally friendly, economical, and can be relied on for consistency. However, like any appliance or piece of equipment in your home, every now and then they’re going to need some servicing or attention to keep them running at their best.

    One of the biggest issues with boilers is low pressure, however, this is usually a quick and easy fix, and sometimes you don’t even need a professional to help you. In this article, we talk about the correct pressure of a boiler, and what to do if your boiler pressure is too high or too low.

    What Is Boiler Water Pressure?

    Boiler pressure is the hot water pressure that travels through the central heating system in your home, whereas the water pressure is what they call the pressure of the water that runs through your kitchen and bathroom. Boiler pressure is incredibly important because it helps to keep the water in your home warm.
    If the pressure on your boiler is too low, then your central heating may not work, and if it’s too high, then it will be under too much strain and could also be prevented from working.

    What is the Right Pressure for a Boiler?

    To find the boiler pressure and to work out whether it’s at the correct setting, locate the in-built pressure gauge that you can find on the exterior of your boiler. It should be sitting at the one bar mark, especially if you’re not currently using the hot water in the house. This is the standard pressure setting for home boilers, and this is a good indication that things are working as they should.

    Why is The Boiler Pressure Too Low or High?

    Once you’ve installed your boiler, it starts to warm up your water, the water is going to expand and cause the pressure gauge to go up. With the in-built relief valve, boilers are prepared to deal with these fast leaps in pressure so if don’t need to be concerned if the boiler is showing a higher pressure than you had anticipated when you are using both the hot water and the central heating at the same time.

    Once you have finished using the hot water and the central heating, however, the pressure should decrease back to a safe level straight away. If you find that the pressure of your boiler is too low, then the gauge is going to be sitting below the one bar mark. If this is the case, then the next thing you need to do is try to get it above the one bar mark.

    What Do I Do If It’s Too Low or High?

    To lower the pressure of your boiler, you can try a couple of things:

    Check the Pressure Relief Valve:

    It’s vital that the pressure relief valve is closed tightly, so if your boiler pressure is too high this is one of the first things that you need to check. When you re-pressurize your boiler, you’ll need to turn the valve so that it can pump water back into the boiler, and it can be easy to forget to close this again.

    However, if you haven’t done this recently, there’s also the possibility that you accidentally knocked it or the valve may have become loosened over time.

    Bleed the Radiators:

    It’s advised that you bleed your radiators in order to reduce the pressure in your boiler as well as your heating system overall. It’s important to keep draining the radiator until you have been able to reduce the boiler pressure back to safe levels as can be seen by the gauge.

    If neither of these work, then there may be something else going on. You may need to re-pressurize the expansion vessel, or you could even have an issue with the filling loop. However, with these types of issues, you’re not going to be able to fix them yourself, so at this point, it’s advised that you call in a professional.

    While your water pressure may still be a little bit sporadic, the relief valve itself should be able to help prevent the boiler from building too much pressure, so you will still be safe even while you’re waiting for help to arrive. Just make sure that you can’t hear any loud or unusual noises coming from your boiler.

    If you’re wanting to lift the pressure of your boiler above the one bar mark, then you need to make sure you’ve turned off the boiler entirely and that it’s hard enough time to get cool before you try to fix it. You will need to find where the filling loop is located in order to fix the pressure – this is going to look a bit like a hose and will have a small valve attached to each end. It should be on the bottom of the boiler. You need to make sure that each end of the hose is connect to its respective valves.

    Use a screwdriver to open the valves, which will allow cold water to fill up the system from the mains. The pressure is going to begin increasing at this point, so it’s vital that you keep a close eye on what the pressure gauge is doing until it goes above the one bar mark.

    Once it’s above this, you can close the valves back off one at a time. You can now switch your boiler back on again and reset it to standard settings.

    The Risks of Low Boiler Pressure

    Thankfully, low boiler pressure is nothing to get too worried about and is not likely to cause any significant damage to your boiler. In saying this, however, it can potentially have a significant impact on the effectiveness and efficiency of your central heating system overall, making it challenging to keep your house consistently warm and ultimately costing you more in heating bills. As a result of this it’s certainly a possibility of needing to get your boiler repaired.

    If you are committed to keeping warm and keeping your bills within budget, then it’s definitely a good idea to do something about low boiler pressure. As always, it’s recommended that you consult a professional if you’re not sure what the issue is. They will be able to correctly diagnose the problem and hopefully fix it as well.

    Online Booking

    Please complete the enquiry form below, and send your details to our customer service team. Once you have completed this form, one of our advisors will contact you to discuss your requirements further and to arrange a suitable appointment.

    Want to talk to someone?

    0808 252 2868

    Contact Us!

    Need to speak to someone about an existing job? Give our customer care team a call!

    Tel: 0808 252 2868

    Head Office: Plumbingforce, Bourne House, 475 Godstone RD, Whyteleafe, Surrey, CR3 0BL

    Plumbingforce engineers in your area

    London   East Anglia   North West   Midlands   South East   South West   Wales

    Before You Go...

    Sign up to our newsletter and enter our prize draw for a chance to win a new boiler system up to the value of £500!