What Causes a Boiler to Lose Pressure?

January 27, 2020 | Boiler Problems, Boiler Repair, Boilers

Boiler Service London. Expert servicing a boiler in London.

Is your boiler losing pressure? It can be very frustrating to go to turn your heating on and to find an error code flashing on your boiler indicating that your boiler has low pressure. Luckily, in many cases, this is a problem that you can resolve yourself. Find out everything you need to know about this all-too-common problem by reading on.

Why Is Boiler Pressure So Important?

Boiler pressure is something that confuses many people. Why is it so important? What does the pressure do? Essentially, boiler pressure is just the balance of air and water inside the sealed system of your boiler. If your boiler is going to work properly, it has to have the right balance of air and water so that whenever you need hot water the system will be capable of supplying it on demand.

If there is too little pressure in your boiler that means that there is insufficient water in the sealed system. The result will be too little water flow to heat the water or radiators in your home. On the other hand, if there is excessive boiler pressure, the water passes too quickly through your heating system. Getting the balance right is, therefore, essential.

Is It the First Time That Your Boiler Has Lost Pressure?

If you’ve woken up this morning and found your boiler has lost pressure for the first time, don’t panic. It’s a very common occurrence. Over time, or even overnight, your boiler can lose water and therefore pressure. All that’s necessary is to top up the boiler or, in other words, to repressurise the system.

How Do you Know If Your Boiler Has Lost Pressure?

You can spot at a glance whether your boiler has lost pressure by just looking at its pressure gauge. This will be on the front of the boiler cover. If your boiler is turned off, your pressure gauge should be its green zone at about 1 Bar. If it is working, the pressure will go up a little then drop down again. It should still stay in the green zone.

How Do I Repressurise My Boiler?

Usually, you can repressurise your boiler at home. Follow these simple instructions:

  • Find the filling loop. This will be directly under the boiler. A filling loop is a silver flexi pipe that has either two or one black tap.
  • Open the tap(s) fully until they are locked at 45 degrees. You’ll see the pressure gauge rising to about 1 Bar.
  • Once the gauge is in the green zone, close the tap(s) by turning them back to the original position.

What If My Boiler Pressure Keeps Dropping? Does That Mean My Boiler Is Leaking?

If your boiler pressure keeps dropping even after you have repressurised it, you will need to call in a professional to determine the cause of the problem.

One of the following is probably the cause:

Your System Is Leaking

It can be hard to spot a leak in your home’s heating system since it could be anywhere in the pipework and may be under the floorboards or in the walls. To identify a leak you should trace the pipework through the property to look for any evidence of leaking. It’s especially important to check around the bends and joints of pipes as seals can weaken with time. If you find a leak, you’ll need to call out one of our Gas Safe Engineers to reseal the system or to re-pipe it if necessary.

Your Boiler Is Old

Boilers don’t last forever and if yours is too old it may not be worth repairing your leak. In such a case, you’re better off replacing your boiler for a new, energy efficient one. Over time, corrosion can set in as can excessive build-up of limescale and this will not only cause further problems, it’ll also make your system less efficient. It’s therefore wise to invest in a new one.

Your Boiler Is Leaking

System leakage is more common than your boiler leaking, but it can occur – usually in order and corroded systems. You can identify a leak in your boiler if you remove its cover and spot any sign of water, but it’s always best to leave this job to one of our Gas Safe Engineers. A boiler leak can only be repaired by a qualified heating engineer as they will have to identify the component that is leaking and then replace the part or the whole boiler.

Faulty Safety Device Or Part

If your boiler is losing pressure due to a faulty part or safety device, a fault code will probably be displayed on the boiler. Whether or not you see a fault code you should call one of our heating engineers. We will be able to determine which component is faulty and then repair or replace it.

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What Do I Do If My Boiler Pressure Keeps Dropping?

If your boiler pressure has dropped for the first time or if it is only an occasional problem, there’s no need to worry. Simply follow the steps outlined above to repressurise your system and you’ll be able to carry on as normal. If, however, the problem keeps occurring and your boiler is unable to maintain pressure for any length of time, it’s time to call in the professionals.

Contact our friendly, fully qualified team of heating engineers today. We can examine your boiler and determine the cause of your boiler losing pressure. We’ll then be able to repair or replace any broken or faulty parts, offer your helpful advice or replace your boiler if necessary. You can rely on us to keep your heating system functioning perfectly at all times so you can enjoy a warm, comfortable home all year round. Give us a call today, and we’ll address your boiler’s problems.

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