Boiler Not Igniting or Firing Up Causes and Fixes

James Elston
Written by James Elston
Updated on 17th May 2024
Posted on 16th May 2024
Topic: Boiler Advice
boiler not igniting or firing up

Boiler ignition issues, such as a boiler not igniting, can be frustrating, especially when you’re in desperate need of hot water or central heating.

But fear not, our experts at Boiler Central will guide you through the maze of boiler troubleshooting, helping you identify and resolve common ignition problems, including the clicking but boiler not igniting issue.

You’re likely here as you have a problem, so let’s get straight into ignition faults on boilers and learn how to keep your home warm and your water hot.

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Boiler Clicking but Not Igniting Overview

  • First things first – immediate actions to check power supply, gas supply and thermostat settings when the boiler won’t ignite.
  • Other basics – Inspect gas appliances and meters regularly for safety.
  • Worst case scenario – Consult a Gas Safe registered engineer if any issues are suspected or for an annual service to maintain the efficiency and safety of your boiler.

What to do When Your Boiler Won’t Ignite

Imagine waking up on a freezing winter morning, only to find out that your boiler is not firing up. Panic sets in as you wonder what could be wrong. But don’t worry, there are several immediate actions you can take to pinpoint the root cause of the problem.

First, check your power supply for any interruptions, as a tripped circuit breaker or blown fuse could render your gas boiler lifeless. Next, ensure that your gas supply is functioning correctly and that low gas pressure is not the culprit. If everything seems fine, it could be a case of your boiler not firing.

Another helpful step is to adjust your thermostat settings, because incorrect configurations can result in boiler ignition failure. If your boiler still refuses to cooperate, it’s time to consult a Gas Safe registered engineer to diagnose and resolve the issue. Remember, safety should be your top priority when dealing with gas-related problems.

Boiler Not Igniting Because of Gas Supply Issues

Boiler ignition problems can often be attributed to a malfunctioning gas supply. To identify gas supply problems, begin by inspecting your gas appliances and gas meter. By doing so, you can identify whether the problem is isolated to your boiler or extends to other gas appliances in your home.

Check Your Gas Appliances

To rule out broader gas supply issues, make sure your other gas appliances, such as your gas hob, are functioning correctly. Visually inspect these appliances for warning signs like lazy yellow flames, black marks, or unusual noises. Confirming that these appliances are securely connected to the gas pipework and have an adequate air supply is equally important.

Keep in mind that consistent maintenance and yearly gas safety inspections by a registered Gas Safe engineer can help ward off potential problems and maintain the safe operation of your gas appliances.

Inspect the Gas Meter

Inspecting your gas meter is another vital step in diagnosing potential gas supply problems. Check for any visible signs of damage, such as cracks, leaks, or corrosion. Also, look for obstructions that might impede gas flow, such as a frozen condensate pipe. If you suspect a gas issue, it’s always a good idea to contact a Gas Safe Registered engineer to diagnose and fix the problem safely and professionally.

Boiler Pressure Levels Stop Boiler Firing Up

Boiler pressure levels are key to attaining peak performance and efficiency. Thus, understanding how to monitor and modify them when necessary is key. Modern boilers come equipped with a pressure gauge that displays the boiler’s pressure level. The ideal pressure for most boilers is between 1 and 1.5 bars. If the pressure is below this range, you can use the filling loop to increase it.

However, if the pressure continues to drop after adjusting, it is likely that there is a fault within the boiler, which requires the expertise of a Gas Safe registered engineer. Regularly monitoring your boiler pressure levels can help you avoid serious issues and ensure your central heating system runs smoothly.

The Pilot Light Clicking But Not Lighting Causes and Solutions

The pilot light is a small flame inside your boiler that ignites the gas to heat the water. If the pilot light goes out or the flame is irregular, your boiler may fail to ignite, leaving you without hot water or central heating. Common causes of pilot light issues include debris blockage, faulty thermocouple, and drafts.

Relighting a Faulty Pilot Light

If your pilot light goes out, you can follow a step-by-step guide to safely relight it:

  1. Refer to your boiler’s manual for specific instructions, as they may vary depending on the brand.
  2. Turn off the boiler and wait for a few minutes to let any residual gas disperse.
  3. Next, locate the pilot light valve and use a long-stemmed lighter to ignite the flame.
  4. Once the pilot light is lit, restart your boiler and monitor its performance.

However, if the pilot light continues to go out or if you’re unsure about the process, it’s best to consult a professional technician or Gas Safe engineer for assistance. Regular maintenance can help prevent pilot light issues and ensure the efficient operation of your boiler.

Central Heating System Checks

If your boiler doesn’t ignite, inspect your central heating system for any possible issues that may be causing the problem. One common issue is trapped air in radiators, which can impede the proper functioning of your central heating system.

Bleed Radiators to Release Trapped Air

If you suspect that trapped air is causing your boiler ignition issues, you can bleed your radiators to release the air and improve the efficiency of your central heating system. To bleed a radiator, follow these steps:

  1. Locate the bleed valve on the radiator.
  2. Turn the valve counterclockwise using a radiator key until all the air is expelled.
  3. Repeat this process for all the radiators in your home.
  4. Once you’ve bled all the radiators, check the pressure gauge on the boiler.
  5. If the pressure is too low, you may need to top up the system with water.
  6. Reactivate the heating system and check if the boiler ignition issues have been resolved.

Regular radiator bleeding can help maintain the efficiency of your heating system and prevent boiler ignition problems.

Frozen Condensate Pipe Complications in Cold Weather

The frozen condensate pipe can also cause boiler ignition problems, particularly in cold weather. The condensate pipe is a plastic pipe designed to drain acidic wastewater away from the boiler. If the condensate pipe becomes frozen, it can obstruct the flow of wastewater and cause the boiler to malfunction.

To thaw a frozen condensate pipe, pour warm water over the exposed end of the pipe until the ice melts. Once the ice has melted, restart the boiler and locate the blockage using DIY methods to complete the thawing process. To prevent future freezing of the condensate pipe, you can insulate the pipe, re-route it, or install a condensate pipe heater.

Faulty Gas Valve

Boiler ignition issues can also result from a malfunctioning gas valve. The gas valve regulates the distribution of gas to both the pilot light and burner. It also helps to adjust the amount of gas flowing through them. A faulty gas valve could be blocked, seized, or have damaged wired connections, preventing the boiler from igniting.

If a malfunctioning gas valve is suspected, contact a Gas Safe registered engineer to safely and professionally diagnose and rectify the problem. Attempting to repair the valve yourself can be dangerous and may result in further damage to the boiler.

Boiler Error Codes and What They Mean

Boiler error codes provide a straightforward way to identify different boiler problems. By familiarising yourself with the meanings of these codes, you can better diagnose and fix ignition problems. For example, error code 0E37 indicates low boiler pressure. Keep in mind that error codes may differ slightly for new boilers.

If you encounter an error code you’re unfamiliar with, consult your boiler manual or contact a professional technician for assistance. Regular maintenance and servicing can help prevent error codes and ensure your boiler operates efficiently.

Is It Time for a New Boiler?

If your boiler is outdated and inefficient, replacement with a newer, more efficient model may be worth considering. An outdated boiler can cause increased energy bills, unexpected breakdowns, and early failure.

When deciding whether to replace your existing boiler, consider the following factors:

  • Age and efficiency of the current boiler
  • Costs of repairs versus benefits of a new boiler
  • Consistency of heating and hot water provided by a new boiler
  • Latest safety features and energy-saving technologies available in new boilers

By assessing these factors, you can make an informed decision about whether to replace your existing boiler.

Annual Boiler Service: A Preventative Measure

Scheduling an annual boiler service is a crucial preventative measure to prevent ignition problems and prolong your boiler’s lifespan. During an annual service, a Gas Safe registered engineer will perform the following:

  • Visual inspection
  • Operation and control checks
  • Flue and combustion release inspection
  • Cleaning of the main boiler components
  • Additional safety and efficiency checks

Regular servicing can help prevent the following issues:

  • Dirt and debris accumulation
  • Gas leaks
  • Carbon monoxide poisoning
  • Increased energy bills

By scheduling an annual boiler service, you can ensure the efficient operation of your boiler and avoid costly repairs or replacements in the future.


In conclusion, understanding and addressing boiler ignition issues is crucial to maintaining a warm and comfortable home. By following the steps and tips outlined in this blog post, you can troubleshoot common problems, maintain the efficiency of your central heating system, and extend the life of your boiler. So, stay warm and keep your boiler in tip-top shape, because a well-maintained boiler is the key to a happy home.

Frequently Asked Questions

How to fix boiler?

Reset your boiler, repressurise it, bleed your radiators, and change the thermostat batteries to fix your boiler. Make sure to refer to your boiler’s manual for instructions.

How to turn on boiler?

To turn on the boiler, locate the control switch and set it to “On”. Next, adjust the thermostat(s) to the lowest temperature, then verify the control valves are working properly.

What are the immediate actions to take when your boiler won’t ignite?

Check the power supply, gas supply, and thermostat settings to troubleshoot your boiler and get it up and running again.

How do I diagnose gas supply issues affecting my boiler?

Check the gas appliances and meter for any visible damage or obstructions to diagnose gas supply issues affecting your boiler.

How can I adjust my boiler’s pressure levels for optimal performance?

To achieve optimal performance, adjust your boiler’s pressure levels by using the filling loop to bring it between 1 and 1.5 bars.

Written by
James Elston
James Elston Director Of Boiler Central
Posted on: 16th May 2024
Topic: Boiler Advice

James Elston is our resident boiler replacement and heating expert here at Boiler Central. With over 20 years experience in the boiler installation industry, James ensures that he knows everything there is about our Gas Safe boiler installations, energy saving and home heating solutions. This can be from simply procuring the latest best combi boilers, to reviewing and ensuring that Boiler Central maintains the highest standards across our boiler installation company.

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