Boiler FAQs

With the weather starting to get colder, it may be time to think about turning the heating back on. If your heating has been off over summer, it is possible that your boiler could require a reset. We've got some handy video guides to show you how to reset a Baxi boiler, and also some basic boiler checks that could help you get your system back up and running efficiently. 


How do I reset my boiler?

If your boiler needs to be reset, these videos show you how, whether your boiler has a dedicated reset button, an ON/OFF/SELECTOR switch or a thermostat control knob.

What’s wrong with my boiler? Try our basic boiler checks.

This five part Basic Checks video series can help you identify and repair basic boiler faults, problems, issues and error codes, helping you save time and money. 

What should the pressure gauge on my boiler be reading?

The normal operating water pressure for your boiler and central heating system is between 1.0 and 2.0 bar. If the pressure drops below 1.0 bar, you need to repressurise it (see above). If the pressure goes above 3.0 bar, you will see water coming from the pressure relief valve (usually on an outside wall). You can reduce the pressure by bleeding a radiator or draining some water out of the system using a drain point , usually found underneath a radiator.


How do I top up the water pressure?

Sometimes boilers need to be repressurised. This is quite normal and you can repressurise your boiler yourself. These videos show you how, whether you have a rigid or a flexible filling loop, or Easy-Fill permanent filling link.

If your boiler has shut down and is showing error code E133 or E28, then your condensate pipe may be frozen. 

Please follow these steps to get your boiler up and running again: 

  1. Switch your boiler off at the control panel, and turn off the electricity at the wall. 
  2. Find where the pipe is frozen, usually the most exposed part of the pipe. 
  3. Warm the condensate pipe across its exposed length using either a hot water bottle, a microwaveable heat pack or warm water poured from a watering can. Do not use boiling water straight from the kettle as this could damage the pipe. 
  4. Turn the power back on at the wall and restart your boiler. Repeat the process until the boiler works again. 


How to avoid frozen condensate pipes

During the winter, external condensate pipes are prone to freezing which can lead to a boiler breakdown. There are some easy steps you can take to avoid this, watch our video to learn more. 



I need guidance on using my Baxi uSense smart control.

We have a number of handy video guides available for the Baxi uSense that cover everything from how to connect to Wifi, how to use the Baxi uSense app and creating schedules. 

Go to the Baxi uSense video guides. 

Why isn’t my water hot?

Combi boilers provide central heating and instant hot water from one single unit. When you turn on the hot tap, a diverter valve inside the boiler opens to let water into the heat exchanger, temporarily closing off the water used for your space heating. When you turn off the hot water the valve switches back to divert heat back to your radiators.

If the water at your tap isn’t hot, it's possible that the diverter valve is either worn, faulty or just stuck in the 'radiator position', therefore not allowing the water to heat up in the first place. Please call either your Gas Safe registered installer or contact Baxi Customer Support on 0330 678 0917.

My hot water fluctuates. Is this right?

Depending on heat output, combination boilers can only supply a one tap at a time. Turning on additional taps will reduce the flow of hot water. If the water is not hot enough you may have to reduce the flow (by turning the tap down) to increase the temperature. This may be necessary especially in winter when the water supply to the boiler is colder.


How often do I need to get my boiler serviced?

Your boiler should be serviced annually by a Gas Safe registered installer to make sure it is working safely and efficiently. An annual service is a required to ensure your warranty remains valid. An annual service is a legal safety requirement if you live in a rented property.

Where can I find the serial number of my boiler?

The serial number can usually be found on the drop down panel on the front of the boiler. Some boilers have a tag underneath the boiler that slides out to reveal the serial number. If you can’t find your serial number, call Baxi Customer Support 0330 678 0917 with the name of your boiler and they will help you find it.

How old is my boiler?

Visit the official industry database. Fill in details of your boiler and the dates when manufacture of that model began and ended will be displayed. You can search for all brands and models of boilers in this database. Or you can look at your boiler’s serial number. This can usually be found on the drop down panel on the front. The serial number has all the information needed for us to tell you when your boiler was manufactured. Contact us with the details.


Serial Numbers

If your boiler was manufactured after 2003, the serial number will look like this, and you can find out the year it was made:
Baxi Form


What sort of boiler do I need?

Answer a few simple questions to find the best boiler for your home.

Where in my house is it safe to install a boiler?

You can have your boiler installed safely in most rooms, or even the loft. There are, however a few things to consider:

  • Your boiler should be installed inside a building and can be fitted to any suitable wall strong enough to take its weight when full of water.
  • The boiler's flue must be able to pass to the outside, either through an outside wall or through the roof.The boiler installation manual gives the minimum legal distances the flue terminal must be from windows, air bricks, other buildings etc, to comply with Building Regulations.
  • As well as the flue, you must consider where to fit the condensate pipe that takes away the liquid that condenses as the gases cool inside the boiler. We recommended that this pipe discharges internally into the household drainage system. If the condensate pipe is fitted outside, it could freeze during cold weather and make the boiler shut down.
  • Our heat only boilers don't require a pump overrun or permanent live. This means you won't need to worry about getting a wire from the pump to the boiler or a permanent power supply to the boiler.
  • If you decide to have it fitted in a garage or outhouse, we recommend you get additional frost protection fitted to protect the system pipework, even if the boiler has its own frost protection. When positioning the boiler, you must allow sufficient clearances and access for servicing. Please check the installation instructions for details.
  • The boiler may be fitted inside a cupboard without having air vents. Modern boilers are room sealed and will run sufficiently cool without ventilation.
  • If the boiler is fitted in a bathroom or shower room, please refer to the current Wiring Regulations and Building Regulations, which explain the different zones in the bathroom where it is safe to install and boiler, and where it is unsafe to do so (In GB this is the current I.E.E. Wiring Regulations and Building Regulations.
  • In IE reference should be made to the current edition of I.S. 813 "Domestic Gas Installations” and the current ETCI rules) If your house is a timber framed building, please refer to the current edition of Institute of Gas Engineers Publication IGE/UP/7 (Gas Installations in Timber Framed Housing)
  • If your boiler runs on LPG (Liquid Petroleum Gas), you should not have it installed in a basement or other position below ground. This is because LPG does not rise, and will therefore not be dispersed should there be a gas leak. This information should be used for guidance only.
  • Your Gas Safe registered installer will be able to survey your home and tell you the most convenient, safest and legally compliant place for your boiler and discuss where the flue and condensate pipe should go.


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