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What To Do If A Boiler Loses Pressure?

How to reduce energy consumption

Unfortunately, a problem can occur with your boiler at any time.  You might wake up and find that you have no hot water and so, that could be down to a loss of water pressure. The good news is that a boiler suffering from low pressure is very rarely a significant problem.

It’s also easy to diagnose and in many cases, you might even be able to rectify the issue yourself. However, to ensure you approach the problem of low pressure the right way, we have created this guide that will help you identify the most common boiler pressure issues and how to fix them.

Boiler Pressure – What Is It?

Your boiler will heat cold water that flows through a myriad of pipes and radiators that are located around your home. In order for the boiler to work efficiently, it needs a stable water pressure. In modern boilers, this is achieved by using a filling loop that maintains the pressure and connects to your cold water pipe.

What Causes Pressure To Drop?

When it comes to low pressure in your boiler, there are two main causes.

The first cause of this problem is a leak. Your boiler system might have a leak that is small yet can still cause problems with your pressure. This is often the case if the leak goes undetected for a period of time. This can lead to a slow drop in pressure that you might not notice initially. So. have a look around your home and look to see if you can find any damp patches. You should also check out the pipes, radiators and the boiler as you might also see signs of a leak here.

However, it is vital that you do not open up the boiler in search of leaks as this can pose a risk. This should only be carried out by a Gas Safe engineer as they will have the training and the experience to identify leaks without causing further problems. If you do identify a leak or you find that you need to regularly top up your water pressure then it could be worth calling a specialist to take a look at your system.

If you have recently bled your radiators then you might have lost some pressure during the process. This is down to the fact that when you bleed a radiator, air is released from the system and that causes the pressure within your boiler system to drop.

How Do I Check The Pressure Of My Boiler?

Many boilers will have the water pressure gauge located on the front. However, this can vary depending on your system but there will be a gauge somewhere in your property. Despite this, they will all look relatively similar. If you have a hydraulic pressure gauge, you will have a low and high pressure that is indicated using red sections on the dial. There is often a red needle that will show the position that was set when the boiler was installed. There are digital gauges though, and this will cause the reading to flash if the pressure is too low or even too high.

If the pressure is below one bar, then it is likely that you have lost water from your system somehow and so, this water will need to be replaced. This is where the filling loop can help. If the pressure gauge reads higher than 2.75 bar then it could be time to bleed a radiator in order to reduce the pressure back down to around 1.5 bar. This can prove to be a challenge and can be dangerous because of high water temperatures. Therefore, it is recommended that you call an engineer to look at the problem of high pressure as this could be caused by a fault within the boiler and could need rectifying by an engineer.

Along with this, it can take time to reduce the pressure by bleeding a radiator plus you will need to ensure you catch the water to prevent it from causing problems to walls and flooring. What is more important to remember is that the water is exceptionally hot and so, it might be safer to call an engineer to do it.

Is It Possible To Fix Low Boiler Pressure Yourself?

Boiler pressure systems can often differ and so, it always advised that you should take a look at your manual to see if it is possible to re-pressurise the system yourself. On the rear of the control panel you can often find instructions, however, if you need tools to remove the panel, don’t do it. At this point, you should call a Gas Safe engineer to do it.

Often, the manufacturer of your boiler will often have helpful videos and tutorials on their website that you can follow, enabling you to top up your pressure yourself. When you repressurise your boiler, you are effectively allowing more water to enter the system via the filling loop from the water mains supply. There are two types of filling loop, one that is internal and one that is external. That can all vary in design but in its basic form, repressuring will require you to turn off your boiler before allowing it to cool.

Then you should make sure that the filling loop is connected securely at both ends. You should then open both valves to allow cold mains water into the system. Watch the pressure gauge until it reaches 1.5 bar. Once completed, close the valve at both ends one after the other then turn the boiler on and press the reset button. Then you should undo both ends of the filling loop and remove it while ensuring you catch any water.

When Should I Call An Engineer?

There is never a bad time to call an engineer, especially when it comes to your boiler. However, if you are in doubt then the best thing to do is call the specialists. You might have followed the manual with very little success or you might not feel comfortable doing it yourself. Whatever the reason, an expert will be able to identify the problem and rectify it.

However, you will need to make sure you call the right people. You need someone who is Gas Safe registered and comes recommended. Your boiler is integral to your home and getting it up and running is crucial but you must remember that it is also a dangerous piece of equipment if you are unsure of what you are doing. Despite this, the good news is that low pressure is often simple to rectify.

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