How to repressurise a boiler?

Published On 14th October 2022
How to repressurise a boiler?
Having a water heating system in your home is like being in a tranquil environment. Many water systems will face pressure concerns at some point. If your boiler isn't working correctly and you're not sure how to repressurise it, keep reading to learn about the problems and fix them.

It's critical to understand how to repressurise a boiler and to resolve a pressure problem. Knowing how to re-pressurise your boiler safely is essential to its continued smooth running.

Your boiler will not be able to heat your home efficiently if it has low pressure. Fortunately, there are various techniques to repressurise a boiler on your own. You may be able to repressurise your boiler while using the filling key to add water or by unlocking the water filling valves, based on the age and type of boiler. Your boiler may recover pressure and resume regular operation. Boiler insurance by Smart Cover is a sort of insurance to cover issues and gives coverage for boiler emergencies and boiler issues like a leaky supply pipe. 


Monitoring the pressure

Examine your boiler's display panel for signs of low boiler pressure. A digital or physical pressure gauge will be found depending on the model of your boiler. The pressure in the system will be indicated via the dial (or bar). First of all, turn off the heating system's electricity and then wait a few hours after switching off your boiler to allow it to cool. In addition, you risk damaging the system or injuring yourself if you don't switch it off and let it cool before working on it.


What is the Ideal Boiler pressure?

Boiler pressure must be in the range of one or two bars. The appropriate boiler pressure is commonly shown as a spectrum in green on the gauge itself. The low and high boiler pressure levels are shown in red. So, please remember that your boiler may continue to function if the pressure is in these red zones. However, if it keeps turning off or won't turn on, you have problems. Even if your boiler is in good operating order, it's essential to check the pressure from time to time and know-how to lower boiler pressure when too high. How to repressurise the boiler or restore pressure if it has dropped too low.


Don't mix low water pressure with low boiler pressure because your water pressure determines how quickly water flows out of your faucets or shower. In contrast, the pressure of the hot water within your heating element on the other hand, is known as boiler pressure.


Repressurise the Boiler

Always start the repressurisation procedure by consulting your boiler's manual. Every boiler is different and depending on the version; you’ll need to follow a few special instructions given below:


Switch the boiler off; before carrying any work on the heating system, it must cool completely. The next step is to examine the boiler's filling system because there is a silver connection between the mains and the central heating circuit. A handle valve is on one end, and an isolation valve is on the other It’s common for the filling loop to leak and sometimes lead to a loss of boiler pressure, so double-check the connections on both ends. Then rotate the isolator valve counterclockwise until the valve's line is parallel to the pipe. 


Rotate the lever valve in the other direction that lets the water flow through the system, bringing pressure levels back into balance, so keep an eye on the pressure gauge. As you open the handle valve, you should see the gauge rise. When it reaches the correct level for your boiler, turn it off. To shut both the handle and isolating valve, crank the handle valve clockwise first, then the isolation valve clockwise. Check if the boiler is now functioning correctly by turning it on.


Repressurise a Boiler with the Filling Loop on the Outside


The term external filling loop means precisely what it sounds like, and it is easy to repressurise your heating unit. To finish the challenge, follow these instructions: 

  1. The cold water pipes and the heating state’s valve should be located in the right place. 

  2. You should notice a silvery hose right next to them, which you will use. 

  3. Take the hose and attach it to each of the valves. 

  4. Open the cold water mains valve first, then the heating system.

  5. Constantly check the pressure gauge; you want it to read at least 1 bar.

  6. Once you've attained the desired pressure, close both valves and ensure the hose is turned off.


Leaking Radiators 

Your boiler system can leak at any point, even if it's only a tiny leak, it might lead to a steady loss of pressure if it goes unnoticed for an extended period. Moreover, watch for evidence of wet patches around the boiler in your home. There's a greater possibility of leaks forming if the boiler pressure is too high. However, another case is if the boiler pressure is too low, the system will not function properly. As a result, maintaining the proper boiler pressure is critical to ensuring that your system heats your house. If you can’t solve the problems, you should get help from an expert. Give one of our professionals a call if you detect a leak or need to regularly top up the water pressure, and they'll be happy to assist you. 


You may have lost boiler pressure if you recently bleed your radiators. When you bleed a radiator, the air is expelled, which causes an overall reduction in volume. The efficacy of your home heating will be seriously harmed if your boilers lose pressure. Moreover, your house will be cold, and you probably won’t be able to have access to hot water. So, don’t forget that your boiler is a pressurised system that keeps the air and water in your home balanced. Your boiler should be serviced once a year to ensure that this does not happen. Maintain your boiler pressure or regularly release air from the heating system. In addition, when your boiler undergoes difficulties with high or low pressure, rest assured that most fixes are simple, and your warmth should be restored in no time.


We aim to offer you peace of mind

Aside from an annual inspection and a quick peek at the boiler pressure monitor, you should keep checking the water pressure in the heating system. Are you concerned about completing this task on your own? Or you don’t know how to repressurise the boiler?  If you're frightened – or think you might have a more severe problem – get help from a professional team, or you can get coverage. The Boiler Breakdown Insurance by Smart Cover covers the issues like boiler breakdowns. Don’t hesitate to contact us because we make your life safe and easy.