A sudden issue with your boiler is never ideal, but these things happen. Yes.. there are few things more inconveniencing than having to go without the heating and hot water you need for your home but it's still annoying all the same.

Below we've listed the most common boiler issues and outlined the potential causes for you. We also highlight some possible fixes, so read on to find out how you can get your combi, heat-only or system boiler back up and running before an inconvenience turns into a plumbing or heating emergency.

Leaking

A boiler leak is usually caused by an issue with an internal component. This can be anything from the  pressure valve to the pump seal. If the leak is coming from the pressure relief valve, it's likely that your system’s pressure is too high. And if the leak occurs because of a problem with the pump seal, the seal could have worn down.

But what if the leak is around the pipes? A leak like this could be caused by corrosion or an issue with the way in which your system was installed in the first place. We recommend that you consult a trained engineer to help identify and fix this particular issue. If the leak is caused by a serious fault, your engineer may recommend that you get a new boiler installed.

Low boiler pressure

Low boiler pressure can be caused by things like a system leak, recently bled radiators or a failed component/ seal. You can usually identify if your boiler’s pressure is too low by taking a look at its built-in pressure gauge. NOTE: Ideally, your boiler’s pressure should be set at the 1.5 bar. If it is below 1, your boiler will not be able to function properly. but how do you identify the issue? You could firstly look for visible signs of a leak, but you should not attempt to remove any casings from the boiler yourself. If you discover a leak or not, we insist you contact a Gas Safe registered engineer.

No heating or hot water

Naturally, it can be very frustrating when your boiler doesn't to do the very thing it was designed to do – providing your home with heating and hot water. But what causes boilers to stop generating heat and/or hot water? It can be caused by anything from faulty valves, broken airlocks or even a broken thermostat. There's a few reasons for a fault like this. 

To determine whether this issue is caused by low pressure, you should check the pressure gauge to see if it is below 1. If it is, it may need re pressurising. If there's an issue with your thermostat, check the boiler's manufacturer guide for the solution – if you can't find out the guide, we recommend that you contact the manufacturer for help. And if none of these suggestions help, we advise that you get in touch with a trained engineer as any other issues will require a professional.

It's not responding to thermostat

Is your thermostat on the right time? It's your responsibility to make sure the device is in line with the new time, when time goes forward or back. In the case your boiler is completely failing to respond to your thermostat, this could mean the controls are broken or old. There are a few checks that you should do before concluding that it's completely done for. For example, try replacing the batteries (obvious, we know, but a very common mistake made by many!). Also try positioning the device closer to the boiler and check if there are any interferences that could be causing the issue in the first place. If the problem with your thermostat continues after these checks and changes, take a look at the instructions booklet for the device or contact the manufacturer directly for help.

Faults with the radiators

Cold patches and other problems are usually caused by a build-up of air or sludge inside of radiators, causing heat to be distributed unequally throughout the system. Check out our blog covering the problems air causes in more detail HERE. A great deal of radiator issues can be resolved by simply bleeding the radiator, a task you can do yourself. Click HERE to learn how to bleed a radiator yourself.

Pilot light keeps switching off

Older boilers may have a permanent pilot light which needs to stay lit in order to light the larger burner within the boiler. If this light keeps going out, there could be a faulty thermocouple that's cutting off the gas supply - not what you want to happen . Other reasons the light might be going out could be a deposit build-up or something could be blowing the light out.

You could try to reignite the pilot light yourself if you are comfortable doing so, but make sure you follow the instructions in your boiler manual. We do, however, recommend contacting a Gas Safe registered engineer to fix the problem.

It's important to note this kind of fault is more common in older boilers than modern ones, as modern systems are not built with pilot lights and ignite electronically. If the issue with your pilot light continues with your current boiler, it may be worth getting a new boiler installed.

Boiler won’t turn on

In the case  your boiler won’t turn on, the first thing you should do is check any other appliances and power supplies in your home to see if they are working. If they are, you need to check the fuse box in your home to see if any of the switches there have tripped or failed. If you still cannot find the cause, we recommend getting in touch with a trained engineer straight away.

If your boiler is turning on but keeps turning off, the pressure could be low or there could be a blockage somewhere within the system. Check your system’s pressure gauge and re-pressurise the boiler if it is set below 1. Alternatively, again you can contact a Gas Safe registered engineer to fix it for you.

Frozen Condensate Pipe

This issue is very common, particularly in the colder months of the year. Your boiler system’s condensate pipe is responsible for transporting the condensate from your boiler to the outside drain. Cold weather can cause the condensate to freeze and block. This is particularly common in homes where the condensate pipe is fitted externally or in an unheated space (i.e. the garage). This issue could cause the condensate to revert back up into the boiler and cause the system to break down.

Boiler breakdown

If left unaddressed, all of the issues above can lead to a complete boiler breakdown. In which case, you should contact a Gas Safe registered engineer immediately. Age and inefficiency can also cause your boiler to breakdown beyond repair. If you have an old, inefficient boiler, we recommend investing in a new system as soon as you can so that you can get the heating and hot water you need. Oh, and a new modern and energy-efficient boiler could also help you save money on your energy bills (BONUS)!