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Boiler Broken - What to Do

🔥 Boiler Broken? What to Do Now

4 min read • Published April 2026

A broken boiler is stressful, especially in winter. But before you panic, there are several quick checks you can do yourself. Many boiler problems have simple fixes - and knowing what to check helps your engineer diagnose the issue faster.

⚠️ Safety First: If you smell gas, hear unusual hissing, or see visible damage, stop immediately and evacuate. Call the Gas Emergency Line (0800 111 999) and do not attempt repairs.

1. Check Error Codes & Lights

What to look for:

  1. Display screen - Modern boilers show error codes (e.g., F1, F28, A00). Write these down exactly.
  2. Pilot light - Look through the boiler's window. Is there a small blue flame? Or is it out?
  3. LED indicators - Red light means fault. Green/amber means operation mode.

Error codes are gold - they tell your engineer what's wrong before they arrive. Take a photo if possible.

2. Reset the Boiler

How to safely reset:

  1. Locate the reset button (usually red) on the boiler - check your manual for exact location
  2. Press and hold for 10 seconds
  3. Release and wait 30 seconds for the boiler to restart
  4. Check if heating/hot water returns

If it works: Great! But note it down. Repeated resets mean an underlying fault that needs fixing soon.

3. Check the Pressure Gauge

Low pressure is the most common reason boilers stop heating.

What to do:

  1. Look at the pressure gauge on the boiler face - it should read 1–2 bar
  2. If it's below 1 bar, pressure is too low
  3. Locate the filling loop (usually a small lever under or beside the boiler)
  4. Slowly open the filling loop until the pressure rises to 1.5 bar, then close it
  5. If pressure keeps dropping, there's a leak - call an engineer
💡 Tip: Take a photo of the pressure gauge before calling. Engineers appreciate this - it saves time on diagnosis.

4. Restart from Cold

Sometimes your boiler just needs a proper restart:

  1. Turn off the boiler at the main control
  2. Wait 5 minutes (this clears any temporary faults)
  3. Turn it back on
  4. Listen for ignition sounds - it should try to light the pilot

5. Check for Water Leaks

Leaking water means pressure loss, which stops your boiler working.

Inspect:

  • Under and around the boiler for drips or pooling water
  • Pipes connected to the boiler - are any wet?
  • Pipework under sinks or in airing cupboards

If you find a leak: Place a bucket underneath and call an engineer immediately. Do not attempt to repair it yourself.

When to Call an Engineer

Do not delay calling if:

  • Error code appears and doesn't clear
  • You smell gas or hear unusual noises (hissing, banging)
  • Water is leaking
  • Boiler won't ignite (no click or whoosh sound when powered on)
  • None of the above checks fix the problem
  • Boiler is older than 10 years and frequently breaking down

What Information to Give Your Engineer

  • Boiler make and model (usually on a label on the unit)
  • Error code(s) displayed
  • When it stopped working (this morning, yesterday, after weather event?)
  • Any sounds: banging, hissing, clicking?
  • Is there a leak?
  • Pressure gauge reading
  • When was it last serviced?

Boiler Still Broken After These Checks?

Gas Safe registered engineers available 24/7 for genuine emergencies.

Call Us Now: 02476 950 595

Key Takeaways

  • Error codes are helpful - write them down or photograph them
  • Low pressure is fixable with a filling loop reset - but leaks need an engineer
  • A hard reset sometimes works, but repeated resets signal an underlying fault
  • Safety first - gas leaks and damage require immediate professional help
  • Most boilers can be fixed, but very old ones may be better replaced