Heating guides · 6 min read
Why is my boiler losing pressure? 6 causes and what to do
Most boiler pressure drops come from a leak in the system, a faulty pressure relief valve or a failing expansion vessel. Check the pressure gauge, look for drips under radiators and around the boiler, and top it up to between 1 and 1.5 bar. If it keeps dropping, call a Gas Safe engineer.
Key facts
Normal pressure: 1 to 1.5 bar cold · Safe to top up yourself: yes · Never open the boiler casing