Check for Combi Boiler Corrosion and Resulting Gas Venting Effects. If your boiler keeps losing pressure sometimes you will not be able to find a leak. If the pressure drops below 1 bar, your pump and boiler will have to work harder, which will cause you problems. We'll show you how the filling loop works with mains pressure, we'll show you how the expansion vessel works and can fail, how the high pressure relief valve can release pressure and how a lack of inhibitor can cause air and a drop in pressure. This can be worrying and annoying, especially if the heating is off and you have no hot water or heating. If your boiler pressure reads less than 1 bar, it’s possible that you might have lost water from the system, which needs to be replaced. We use cookies to anonymously learn how our visitors use our site, so that we can improve it. Random Acts of Kindness and All things Positive! Its purpose is to accommodate the expansion of the water when it’s heated. There may be a faulty valve that needs replacing - or the issue may lie with a component inside the boiler itself. Why does my boiler keep losing pressure? My Baxi combi boiler is losing pressure overnight when not on, the next morning I re pressure up to 1.5 bar with system off. Does the pressure in your combi boiler or heating system boiler keep dropping? 99% of the time, a boiler losing pressure is a leak. If your combi boiler loses pressure, it can be an annoying disruption to your home comfort, especially in winter when you rely on your central heating to keep you and your family warm. at this point I have to let water out of the system to get the bar down to 1.5 again, just to have heating & hot water through the evening. Hi. The boiler has built up too much pressure due to the expansion vessel failing or losing its charge The pressure relief valve is not seated correctly, causing water to pass by it For safety reasons, it’s best to call out a Gas Safe registered engineer who can come and fix this problem for you. The expansion vessel consists of two internal compartments divided by a rubber diaphragm. Firstly, if we explain what a sealed system is, you’ll find it much easier to understand why your boiler keeps losing pressure. If the pressure goes below 1 bar, then sometimes depending on the combi you have then the boiler will not operate. MSE's MARTIN LEWIS TACKLES QUESTIONS FROM MPs ABOUT HOW CORONAVIRUS HAS AFFECTED YOUR PERSONAL FINANCES - AND SPEAKS UP FOR THOSE WHO HAVE MISSED OUT ON HELP, http://www.screwfix.com/p/sentinel-internal-leak-sealer-1ltr/99730. And just top up the pressure (we’ll tell you how, further down). Is Your Boiler Losing Pressure But There is No Leaks? Editor, Marcus Herbert. One of the most common reasons for a boiler to lose pressure is an actual leak in the … Add more inhibitor fluid. The pressure on the combi boiler should be at 1.5 bar or between 1 bar and 2 bar. Pressure loss may be caused from a leak in the pressure relief valve, an issue in the expansion vessel, air in your system, or a leak in the heating pipework itself. On most pressurised systems this is expelled automatically from an air vent. It’s unlikely that the … The next thing to stress over is the pump speed. familiarise yourself with the latest version. A boiler losing pressure can be caused by a number of things. We hope you don’t mind! The new, low pressure may be too low to operate the boiler. If we had £1 for everytime we’d heard the question, “why does my boiler keep losing pressure?”, we’d have at least £247 by now!. Your combi boiler can be losing pressure for a number of reasons. How to repressurise and reset your boiler. It’s as simple as that. In most cases, we find that the central heating has been checked for air in the radiators or work for example a radiator has been taken of the wall. We don't as a general policy investigate the solvency of companies mentioned (how likely they are to go bust), but there is a risk any company can struggle and it's rarely made public until it's too late (see the. Sometimes the system is creating air. So if this is your boilers first rodeo – relax. Simply ensure that you’ve got a great quantity of inhibitor in your heater. When the heating system is cool, the pressure should be between 1 and 1.5 bar on the pressure gauge (the indicator needle would usually be in the green section). Get around this problem by adding inhibitor to the heating system. We'll show you why it happens and how to fix it. Always remember anyone can post on the MSE forums, so it can be very different from our opinion. 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