How To Reset A Boiler (Even After A Powercut)

A boiler that does not turn on is not the ideal unit for your house as it could cause severe damage to your pipes. However, some of the modern boilers lockouts as soon as it is at risk of damage.    

Once you get it repaired, you need to know how to reset the boiler to enjoy the hot water in cold weather. Below is everything you need to know about how to reset the boiler even after a power cut. 

How Do I Reset My Boiler?

Every boiler has a reset button located in different areas, depending on what model you use. If you cannot find the switch, refer to the boiler’s manual that will also tell you about resetting your appliance. 

Once you find the button, press it and hold it for 10 to 15 seconds. After you leave it, the boiler will start heating in a few minutes. However, if it does not heat, do not press the button repeatedly, leading to severe damage. 

When your boiler has reset, it will ignite and show you a green light that indicates the appliance is working. If the boiler does not reset, you need to contact the company or an engineer to fix the issue.


What To Do In Case Of A Power Cut?

During a power cut, the central heating system does not work due to the lack of electricity. Even though a boiler needs gas to heat water, it won’t run without adequate power. So, how do you rest your boiler even after a power cut?

In most cases, you only need to find the reset button and hold it for at least 10 seconds. However, you can also adjust the central heating temperature by turning the knob counterclockwise to the reset position. Hold the knob there for five seconds and then turn it back to its normal temperature. If the boiler still doesn’t work, you should call a professional to repair it.

Why Do You Need To Reset Your Boiler?

Modern system and combi boilers come with a safety feature that shuts off the appliance whenever it is at risk of damage. Due to the shutdown, the boiler goes into a lockout and needs to be reset to start functioning again. 

You can refer to the display screen that shows you the error code to find out the problem in your unit. It may also be due to poor gas supply, which is not a safe working condition for the boiler. And before you reset your boiler, make sure to get these issues repaired first by contacting boiler engineers. 

Why Is My Boiler Not Igniting?

There are several reasons why your boiler is not igniting for hot water or central heating. Here are a few common ones: 

  • Fault in the gas valve 
  • Insufficient gas 
  • Low gas pressure 
  • Damaged fan 
  • Blocked jet 
  • Electrode and Ignition lead

How To Fix The Ignition Lockout On A Boiler?

If boiler lockout is an issue, you may have to reset your boiler to fix it. However, resetting the unit may not be the best solution in some situations. Make sure to check the following issues in your boiler to determine the exact problem.  

  • Pump: The pump might feel too hot due to seized internal parts. 
  • Boiler pressure: Check whether the boiler is working with the correct gas pressure or not. 
  • PCB: If the PCB is not working, the boiler will lockout in a second. 
  • Power Supply: Check whether it is getting the required power supply. 

If this is a regular issue, it may be time for a new boiler or at the very least time to contact a qualified engineer.


How Do I Increase Pressure In My Boiler?

A boiler needs the appropriate gas pressure to work at maximum efficiency. Sometimes the pressure decreases, and the system stops functioning. In this case, you need to refer to the manual first and take the following steps if you still face this problem:  

  1. Find the pressure gauge. 
  2. The gauge will show you a green light, indicating that the level of pressure is accurate. 
  3. Shut down the boiler. 
  4. Turn the filling loops and adjust them to an angle facing the pipe’s direction. 
  5. Check the pressure gauge to know whether the pressure is higher, lower, or accurate. Once it reaches the right pressure level, you have to close the handles. 
  6. You can turn your appliance on to see whether it is working efficiently or not. 

How Do I Reconnect My Thermostat To My Boiler?

If you have a regular thermostat, you need to connect it with the boiler through wires. However, you can connect a wireless thermostat to the boiler and carry it from one room to another. With advanced technology, even old gas boilers can have wireless connections with the thermostat. 

Smart thermostats are the latest gadgets that you can connect with your boiler using a Wi-Fi connection. You can use a smartphone or a PC to control the thermostat from anywhere in the world. Some of these modern thermostats can even tell you when you need heat and turn the appliance on or off accordingly.  

My Boiler Needs Regular Resetting. What Can I Do?

If your boiler needs constant resetting, it might be due to some internal fault in the appliance. These faults include: 

  • A faulty pump
  • Blocked plate heat exchanger
  • Leakage in the system
  • Fault in an electric part

If you are resetting your boiler constantly, it is possible that the system has lived its life and needs a replacement and it might be time to contact a gas safe registered engineer.  

How Do I Reset My Thermostat?

There are different ways to reset a thermostat, varying on the type of thermostat you are using. Here is how you can reset different types of thermostats:  

  • For programmable thermostats, you can remove their batteries and insert them back. If the screen turns on, you have successfully reset your thermostat. Test the device to see if the reset has resolved the issue. 
  • If you have a low voltage thermostat, you have to clean its components gently using a brush. After that, you can test it at different settings as your thermostat has been reset. 
  • If you own a mechanical thermostat, you should start the resetting process by turning it off. Then, you have to turn off the HVAC system and wait for at least 30 to 45 seconds to turn it back on. 
  • With Non-programmable digital thermostats, all you need to do is press the reset button and hold it for five seconds. You can also remove its batteries and insert them back after a few seconds.

So that’s it how to reset a boiler should be fully covered here. Check below for some other common boiler issues.

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Last Updated on November 7, 2021

Frequently Asked Questions

What does 0 mean on a boiler?

If the display screen on your boiler shows a 0, it means the unit is on standby and waiting for the central heating system to turn on.

Do all modern boilers have a reset button?

Yes, all boilers have a reset button located at different places on the appliance. Normally, you will find the button on the burner unit.

Where is the reset button on a boiler?

Usually, the reset button on most boilers is on the burner unit. You may have to remove the front cover and press the reset button. But remember to check the boiler’s manual to know the number of times to press.

What is boiler lockout?

Modern boilers go into lockout for multiple reasons, including ignition failure, damaged PCB, and blocked heat exchanger. They might also lockout if the water pressure is either too high or too low for their proper functioning. You can fix the boiler issues yourself or call a professional to help you resolve them. The fault code on the display may indicate the reason in more depth.

If you are at all worried, you should contact a qualified engineer to take a closer look.

David Thompson

Author: David Thompson

Dave has been involved in the UK building sector for over 3 decades and has developed a particular interest in energy efficiency in the home.

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