Blog>Questions>Why is my combi boiler losing pressure if there's no leak?
Last updated: 10 February 2025
Why is my combi boiler losing pressure if there's no leak?
A common question we get asked is: why is my combi boiler losing pressure if there's no leak? Find out the answer in this quick read.
There are a number of reasons why a boiler could lose pressure. Here are some of the most common:
There's a leak – Although you might not have located a leak in your heating system yet, it is one of the most likely causes. It might not be obvious so we recommend hiring a boiler engineer to thoroughly check your boiler and heating system
Boiler needs to be re-pressurised – Over time, boilers will naturally lose pressure slowly. If that's the case, you simply need to re-pressurise the boiler
Air pockets in radiators – If any air has built up in your radiators, it can cause a drop in boiler pressure. If that's happened in your home, you simply need to bleed your radiators
Faulty pressure release valve – The pressure release valve helps control the pressure in your heating system. If the valve is faulty, it could cause your boiler to lose pressure
Faulty pressure gauge – This is an uncommon issue, but could be extremely dangerous. If you have reason to believe that your pressure gauge is faulty, contact a local boiler engineer immediately
If your boiler is losing pressure, we would always recommend speaking to an experienced local boiler engineer. A qualified professional tradesperson will be able to identify the issue and remedy the problem.
Want to know more? Check out our guide to common boiler faults.
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