Topping up the pressure on your boiler

One of the most common boiler faults is low boiler pressure. It is normal for the central heating system to lose pressure over a period of time. If you have bled your radiators recently, pressure could be lost due to that. Or it may be that there is a leak somewhere in your heating system. Sometimes leaks can be so small that they’re unnoticeable. It is recommended that you check your boiler pressure at least once a month to help reduce the chances of unexpected boiler breakdowns.

Your central heating boiler must have an operating pressure between 1 bar and 2 bar. Being at this pressure keeps the central heating boiler and central heating system free from air. If the pressure drops below the normal boiler pressure level, a safety switch is activated that cuts the boiler off - this is done to prevent damage to the central heating system and boiler. It also prevents both the central heating system and boiler from running dry (with no water circulating).

If your boiler has low pressure, you can top up your system and have your boiler working within a few minutes by following the steps below:

  1. Look for the filling loop under the boiler. It will connect between 2 pipes. There are a few variations of filling loops, and for your reference we’ve included an image of a common filling loop below
  2. On each end of the filling loop there will be a valve which should be closed.This can be checked as the valve handle has to be positioned horizontally across the filling loop .
  3. Are the valves  in the same position? If they are not, operate them so they are both horizontal.
  4. Open one valve fully and then open the second valve slowly. Keeping your hand on the valve, you will hear the water entering the boiler. Watching the pressure gauge, you will see the black needle rising. Ideally the pressure should be 1.5 bar, or the needle should be at the 10 o’clock position.
    When the needle reaches the desired position, close both the valves and reset the boiler. You should now have central heating and hot water .It’s normal to top up your boiler every few months, but if you find you have to top up the boiler every day or every week, and if you have a CORGI HomePlan policy, please call us at 0800 085 0845 and report a fault and arrange for an engineer to attend.
  5. The boiler pressure gauge will normally be located on the front panel or underneath the boiler. The pressure gauge may also be digital on certain boilers, this can be found by pressing the information button continually until the screen displays a bar reading. 

 We’ve included some helpful links on topping up the pressure for some of the most common boiler brands. If your boiler is not listed, enter your boiler make with the phrase  “top up boiler pressure.” For example: “Baxi boiler how to top up pressure.”

Please note that if you use the following links from a third party, CORGI HomePlan will not accept responsibility for the information given. If you are unsure or are not confident on how to top up the boiler pressure and have a policy with us call CORGI HomePlan on 0800 085 0845 and a member of the team will be happy to help.

For information about our boiler cover and annual servicing, click here.

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Your CORGI HomePlan policy is arranged and administered by CORGI HomePlan Ltd, a firm authorised and regulated by the Financial Conduct Authority under firm reference number 824122 to carry on insurance distribution. CORGI HomePlan Ltd is registered in Scotland (Company No. SC358475). Registered Office: 1 Masterton Park, South Castle Drive, Dunfermline, KY11 8NX.

The insurance policy is underwritten by OVO Insurance Services Ltd, a firm authorised and regulated by the Guernsey Financial Services Commission under reference number 2570126. OVO Insurance Services Ltd is registered in the Bailiwick of Guernsey under the Companies (Guernsey) Law 2008 (Company No. 67013). Registered office: PO Box 155, Mill Court, La Charroterie, St Peter Port, Guernsey, GY1 4ET.

CORGI HomePlan Ltd and OVO Insurance Services Ltd are part of OVO Group Ltd