
Why Is My Boiler Not Working?
It’s a chilly winter’s day, and the warm embrace of your home is slowly giving way to the cold as your boiler stopped working. This is a situation many homeowners experience, and it can be incredibly frustrating and stressful.
Whether your boiler has completely shut down, is struggling to keep you warm, is unresponsive, or shows a confusing fault code, it’s important to take a deep breath and remember that you’re not alone. Many common boiler issues can be diagnosed and even resolved right from the comfort of your home, helping you save both time and the cost of a service call.
At 24|7 Home Rescue, we understand the urgency of restoring your heating system without unnecessary stress. This detailed guide will provide you with:
1. Initial steps to verify whether your boiler is indeed malfunctioning
2. Common reasons that lead to boiler breakdowns
3. Detailed, step-by-step self-help checks you can perform
4. Guidelines for when to contact a Gas Safe registered engineer
5. Information on what to expect when seeking our assistance
Quick First Checks: Is Your Boiler Really Out of Order?
Before diving into more complex troubleshooting related to boiler not working, take a moment to run through this concise checklist:
Power Supply: Is electricity functioning throughout your home? Double-check the sockets and inspect your fuse box for any issues.
Gas Meter Status: If you use a prepaid meter, verify it hasn’t run out of credit. Make sure the gas meter is operational.
Thermostat Function: Is your thermostat set to a temperature that calls for heat? Ensure it’s on and functioning properly.
Boiler Display Codes: Does the boiler display show an error or fault code? Take note of any codes for reference.
Pressure Gauge Level: Check if the pressure gauge reads below 1 bar, which may indicate a problem.
Other Gas Appliances: Are your other gas appliances, such as your cooker, functioning correctly?
Radiator Temperature: Are your radiators evenly warm, or are some cold?
Pilot Light Status: If you have an older boiler, check to see if the pilot light is lit.
9 Common Reasons Why Your Boiler Is not Working (and How to Fix Them)
Let’s explore the most frequent boiler issues that homeowners encounter and steps you can take to potentially rectify them.
1. No Power to the Boiler
Cause: This can occur due to a tripped fuse, a power outage, or a switch being turned off.
Fix: Inspect your fuse box (also known as the consumer unit) to see if any circuits have tripped. Ensure that the boiler switch is in the ON position and that the plug is securely connected. If everything seems normal, try resetting the boiler using the button on the control panel.
Related Article: Reasons and fixes for No Power to Your Boiler
2. Low Boiler Pressure
Cause: This could result from leaks within the system, recent radiator bleeding, or natural pressure loss over time.
Fix: Locate the pressure gauge on your boiler, it should ideally be between 1.0 and 1.5 bar. If the reading is low, you can carefully repressurise the boiler using the filling loop, typically situated under the boiler. Make sure you only attempt this if you feel confident; otherwise, consult a professional.
Related Article: How to increase boiler pressure
3. Frozen Condensate Pipe (Specific to Cold Weather)
Cause: In winter, the external condensate pipe may freeze, preventing proper boiler function.
Fix: Carefully pour warm (not boiling) water over the frozen section of the pipe. Once the blockage is cleared, attempt to restart the boiler.
Related Article: How to defrost frozen condensate pipe
4. No Gas Supply
Cause: Issues may arise from the gas supply being shut off, a prepaid meter running low on credit, or an internal system fault.
Fix: Test other gas appliances in your home, such as your gas cooker. If they are also nonfunctional, there may be a broader issue with your gas supply. For prepaid meters, confirm your balance and top up if necessary. Additionally, check if the emergency control valve near the meter is fully open.
5. Thermostat Not Responding
Cause: This can happen if the thermostat is turned off, needs a battery change, or is set to a temperature that is too low.
Fix: Ensure that the thermostat is powered on and actively calling for heat. If it’s a wireless model, replace the batteries if required. Adjust the settings to a temperature above the current room temperature.
Related Article: The boiler is not responding to thermostat
6. Boiler Lockout or Fault Code Displayed
Cause: Various issues can lead to a boiler lockout, including ignition failures, fan malfunctions, or overheating.
Fix: Refer to your boiler’s manual to interpret the fault code. You can attempt to reset the boiler by pressing the reset button, but if the problem persists, do not hesitate to contact a Gas Safe engineer for further assistance.
7. Pilot Light Out (Applicable to Older Boilers)
Cause: Drafts, a faulty thermocouple, or problems with gas supply are common culprits.
Fix: Follow your manufacturer’s instructions to relight the pilot light. If it fails to stay lit, this may indicate that a part needs replacing.
Related Article: My Boiler Pilot Light Keeps Blowing Out
8. Airlocks in the System
Cause: Trapped air can affect water flow in pipes or radiators, especially after conducting radiator bleeding.
Fix: Use a radiator key to bleed air from your radiators. Start with those closest to the boiler and progress outward until all radiators are functioning properly.
9. Boiler Making Unusual Noises (Banging, Gurgling, or Whistling)
Cause: This could be due to limescale buildup, air trapped in the system, or pump failure.
Fix: If you’re hearing gurgling sounds, bleed your radiators. A “kettling” noise, akin to a kettle boiling, may indicate scale buildup, indicating it might be time to call an engineer.
What to Do Before Contacting a Professional
Prior to making a call for professional help, consult this straightforward checklist of self-checks, these could save you valuable time and money:
Step | Action |
---|---|
1 | Check if your fuse box has tripped and reset it if needed |
2 | Top up your gas (for prepaid meters) |
3 | Check your thermostat settings and replace batteries |
4 | Reset the boiler via the control panel |
5 | Check the pressure gauge and repressurise if it’s low |
6 | Thaw your condensate pipe if it’s frozen |
7 | Bleed radiators if they’re only warm at the bottom |
8 | Relight the pilot light if it’s gone out (only if safe to do so) |
If at any point you feel uncertain or unsafe while performing these checks, stop immediately and contact a professional for assistance.

Boiler Service
Ensure your boiler runs efficiently and safely with our professional boiler servicing. Regular maintenance will save you money in the long run and potentially prevent breakdowns.
When to Contact a Gas Safe Engineer
It is crucial to call an engineer as soon as possible if:
- Your boiler displays a recurring fault code and resets are ineffective.
- You detect the smell of gas or suspect a gas leak (contact emergency services immediately at 0800 111 999).
- The pressure continues to drop, even after attempting to top it up.
- Water is leaking or dripping from the boiler.
- You hear odd or excessively loud noises coming from the unit.
- After performing all self-checks, you still have no hot water or heating.
- The boiler fails to turn on altogether, despite having an adequate gas and power supply.
- You suspect an internal fault, such as a broken pump, malfunctioning fan, or valve issues.
Let 24|7 Home Rescue Assist You
If you’ve followed all the steps and your boiler is now back in working order, that’s great news! However, it’s important to remember that regular maintenance is key to preventing future issues. The best way to keep your boiler running efficiently and safely is through an annual boiler service. If you’re looking for a reliable and trusted provider, contact 24|7 Home Rescue today on 0345 3192 247. Our expert team is here to ensure your boiler stays in top condition all year round.