Boiler Not Igniting? Common Issues and How to Fix Them

A boiler is one of the most essential appliances in almost every UK home. It is meant to provide heating in the living rooms and hot water in taps and showers, throughout the colder parts of the year. But the problem starts when there is no heating or no hot water in taps and showers. While there might be many reasons behind it, one of the most common reasons is that the boiler fails to ignite. Again, there may be several reasons a boiler fails to ignite.

Under normal circumstances, it is often quite a simple error that prohibits a boiler from igniting. While mostly the reason is simple, it can be fixed quite easily on your own, without calling a Gas Safe-registered engineer. However, in more complex situations, the problem may be serious enough to require a qualified engineer. Hence, it is very important for the homeowners to have at least a basic awareness of how to identify the actual issue in this scenario, and more importantly, how to fix it and when to call a Gas Safe-registered engineer.

Keep reading this blog to identify the common issues and how to fix them if a boiler is not igniting.

Boiler Not Igniting – How To Identify

If a boiler fails to ignite, it means its burner will not be igniting as well.  It will prevent the boiler from heating water. This can be identified by noticing one or more indications as listed below:

1.       There is no heating in the home.

2.       There is no hot water at the taps or in the showers.

3.       An error code appears on the display panel of the boiler.

4.       There may be a flashing red light depending on the make and model of the boiler.

5.       The boiler produces clicking sounds, but without ignition.

6.       The boiler repeatedly attempts to start but shuts down after a short time.

7.       The boiler goes completely unresponsive.

Most of the modern boilers are equipped with a safety mechanism that forces them to shut down if there is something wrong or if a fault has occurred in their system. Hence, failure to ignite might be the result of the activation of the safety mechanism of the boiler to protect it from further damage.

Boiler Not Igniting – Most Common Reasons And How To Fix Them

Some of the most common reasons for a boiler not igniting and how to fix them are summarized below:

1.     Gas Not Available – Gas Pressure Is Low

This is one of the most common reasons for a boiler not igniting. If the gas supply is disrupted for any reason, obviously, the boiler cannot ignite. Mostly, it may happen due to one of the following reasons:

·         Gas supply might have been switched off at the meter, either intentionally during repair work or unintentionally by mistake. This can be checked by igniting some other gas appliances, such as a hob or a gas fire. It can also be checked from the gas inlet valve, often installed alongside the meter.

·         Your gas supply may have been disconnected due to insufficient credit on your prepaid meter account. This can be verified by logging into your prepayment account.

·         The gas supply may have been temporarily disconnected by the energy supply company for repair, maintenance, or upgrade work. This can be checked either by visiting their website or calling them.

How To Fix This Issue?

·         If the gas supply is accidentally or mistakenly cut off at the gas inlet valve, open it. Remember, the handle of this valve should be parallel to the pipe. If it is at a right angle to the pipe, it means the valve is closed and needs to be fully opened to restore the gas supply. A half-opened valve may result in low gas pressure.

·         If the credit balance in your prepayment account has been exhausted, top it up to get an uninterrupted gas supply in your home.

·         If the gas supply is temporarily disconnected by the supplier, contact their helpline for an update on the expected restoration of service. In this case, you can only wait for the restoration of the gas supply by the energy supply company.

2.     Boiler Pressure Is Low

Modern UK boilers are designed to operate at 1.0-1.5 bar. The safety mechanism on these boilers shuts them down if the pressure drops below the set level. Mostly, in this case, the boiler displays an error code, such as F22, EA, or E10, depending on the make and model. When it happens, the boiler cannot fire up. The most common cause of low boiler pressure is radiator bleeding.

How To Fix This Issue?

The solution to this issue is quite simple: top up the boiler pressure. This can be done by using the filling loop. Slowly open the valves at both ends of the filling loop to allow water to enter. Top up the pressure somewhere between 1.0 and 1.5 bars. Then tightly close both valves. Under normal circumstances, the boiler should ignite properly now. If the problem persists and pressure continues to drop, the issue may be with the expansion vessel or there may be leaks. You will need to call a Gas Safe-registered engineer to resolve the issue.

3.     Ignition Electrode Is Faulty

The ignition electrode plays a crucial role in igniting the boiler. When the boiler needs to be ignited, this electrode generates an electric spark that activates the burner. If the ignition electrode is dirty or has worn out, it may not produce a spark, resulting in ignition failure. When the boiler makes a clicking sound without producing a flame, or repeatedly attempts to ignite but fails, it indicates a faulty electrode. After several unsuccessful attempts, the boiler may enter the lockout mode.

How To Fix This Issue?

This problem cannot be fixed on your own. In this case, you will have to call a Gas Safe-registered engineer for the detection of the actual cause and replacement of the ignition electrode, if required.

4.     Condensate Pipe Is Frozen

The condensate pipe is an essential component of a condensing boiler. This type of boiler produces acidic condensate. This condensate is drained out through an external pipe. During extreme cold, there is a high likelihood that this pipe will freeze. When this pipe is frozen, the boiler will not ignite due to activation of the safety mechanism. If the condensing boiler produces gurgling sounds, it may indicate a frozen condensate pipe. When it happens, the boiler also displays an error code. 

How To Fix This Issue?

·         Search for the condensate pipe. Mostly, it is a white plastic pipe, located outside the home.

·         Thaw it with lukewarm water. Never use boiling water to defrost this pipe.

·         Instead of thawing it with warm water, it can be wrapped with a warm towel.

·         Once the pipe is thawed, you may reset the boiler.

·         As a precautionary measure, the condensate pipe should be sufficiently insulated before the onset of the extreme cold season.

5.     Condensate Trap Is Blocked/Faulty

Sometimes the condensate trap, located inside the boiler, may develop a fault or blockage. When this occurs, the boiler cannot drain the condensate, triggering the safety mechanism to shut down the boiler. Unusual sounds and frequent shutdowns are obvious signs of a faulty or blocked condensate trap. Additionally, the boiler also displays a relevant error code, depending on the make and model.

How To Fix This Issue?

This problem cannot be and should never be attempted to be fixed on your own. Only a qualified boiler engineer, preferably a gas safe registered engineer, can handle it.

6.     Airlock Has Blocked Circulation

An airlock may block the circulation of hot water, which prevents the boiler from igniting. The common symptoms of this issue are cold radiators and unusual bubbling sounds. In this case, the boiler may fire up for a short time and then shut off.

How To Fix This Issue?

·         Release trapped air through radiator bleeding.

·         Top up the boiler pressure after radiator bleeding.

7.     Thermostat Is Faulty

In some cases, the thermostat may be faulty, which includes faulty batteries, incorrect temperature settings, or a connectivity issue with the smart thermostat.

How To Fix This Issue?

·         Replace thermostat batteries.

·         Correct the temperature settings, ideally above the room temperature.

Conclusion

Failure to ignite is a common fault that typically points to another fault in the boiler itself, although it may not be the actual cause. Therefore, homeowners should be well-trained to identify the actual reason a boiler fails to ignite. In most cases, this can be fixed on their own; however, they may sometimes need to hire a Gas Safe-registered engineer. Before calling the engineer, try to identify the cause of this common issue and resolve it yourself.

However, if the issue is serious and cannot be resolved on your own, don't attempt it; call a Gas Safe-registered engineer to identify the root cause. Remember, a boiler contains some sensitive internal components, which can only be handled by a professionally qualified boiler engineer. If the problem is with any of these components, do not attempt to fix it yourself.