What to Do When Your Boiler Stops Working
If your boiler stops working, stay calm. Most issues are simple to check before calling a heating engineer. Start here.
Check the Pressure Gauge
Look at the pressure gauge on your boiler. The needle should sit between 1 and 1.5 bar. If it’s below 1 bar, the system is low on water.
To top up: - Turn off the boiler. - Locate the filling loop (a small metal or plastic hose with two taps). - Open both taps slowly. You’ll hear water flowing. - Close the taps once the gauge reaches 1.2 bar. - Turn the boiler back on.
If the pressure drops again within a few days, there may be a leak. Don’t keep topping up — call a Gas Safe engineer.
Reset the Boiler
Many boilers have a reset button (often red or black). Press and hold it for 5–10 seconds. Wait 30 seconds and see if the boiler restarts.
If it doesn’t, check the display. Some models show a fault code (e.g., ‘E10’, ‘F23’). Write it down. This helps a technician diagnose the issue faster.
Avoid resetting repeatedly. If the boiler keeps tripping, stop and call a professional.
Look for Common Faults
- No hot water? Check if the boiler is set to ‘Central Heating’ or ‘Hot Water’ mode. Ensure the thermostat is set above room temperature.
- No heating? Check that radiators aren’t locked off. Bleed them if they’re cold at the top.
- No power? Ensure the boiler’s power switch is on. Check the fuse in your consumer unit (circuit breaker). A tripped breaker is common.
- Gas Safe requirement: Never attempt repairs if you’re not Gas Safe registered. Faulty gas work is dangerous and illegal in the UK.
When to Call a Heating Engineer
Call a Gas Safe registered engineer if: - The boiler won’t reset or keeps failing. - You see water leaks or hear unusual noises (gurgling, banging). - The fault code persists after a reset. - You’re unsure about gas safety.
Costs vary. A call-out can range from £60 to £120, depending on location and time. Repairs depend on the issue — a simple part replacement might be £50–£150, while a full boiler replacement starts at £2,000.
Avoid These Mistakes
- Don’t keep resetting a boiler that keeps failing. This can damage the system.
- Don’t ignore a low pressure reading. It can lead to boiler damage.
- Don’t attempt gas repairs yourself. It’s illegal and unsafe.
- Don’t assume the boiler is dead. Many issues are temporary or fixable by a quick check.
Find Trusted Help Fast
If you need a qualified engineer, ASKU connects you to local, Gas Safe registered heating professionals. Send a quick WhatsApp message with your boiler model and fault code — we’ll match you with someone nearby who can help.
Stay warm, stay safe, and act only when you’re sure it’s safe to do so.