Common Ariston Boiler Problems and Repairs

All boilers, including Ariston boilers, consist of moving components, which means they are likely to develop a fault at some time or another. Whilst some issues are easy to diagnose and might even be something you can fix yourself, most common boiler problems require the help of a trusted Gas Safe registered engineer. Some Ariston boiler problems are more common than others, and it’s worth you knowing what they are and the steps you need to take to fix them when they occur. 

Below, we explain the most common Ariston boiler problems that can happen and how to solve them. 

1. Low water pressure

Low water pressure is one of the most common problems with all boilers, regardless of the brand. The boiler pressure range should be between 1 and 1.5 bar, so be sure to check the pressure gauge. If your Ariston boiler has got low water pressure, you will probably see fault code 108 on the boiler display panel. The cause could be a leak in your boiler or somewhere in your central heating system, but it may be that you need to add water to your system to increase the boiler pressure. 

What to do next: See whether you can find a leak coming from your boiler or any other part of your central heating system. If you spot one, call out a Gas Safe registered engineer to check your system and fix the leak. No leak? You can use the external filling loop to add water and increase the boiler pressure to the correct range. Then, reset the boiler to clear the fault. 

2. Lack of circulation

If your boiler has insufficient circulation, the fault code 103, 104, 105, 106 or 107 should appear on the display panel. There are many possible causes of lack of circulation, including a blockage or a heat pump problem. It could be that there is an issue with your central heating pump, such as airlocks, blown seals, worn out shaft or bearings or even incorrect installation. 

What to do next: If you suspect the pump is faulty, you have a blockage, or you are unsure, you must call out a Gas Safe registered engineer to either replace the pump, perform a power flush to remove any sludge in the system or find the reason for the lack of circulation. 

3. Ignition failure

Another common problem with Ariston boilers is ignition failure, which may cause the error code 5P1 or 5P2 to show on the display panel. An ignition fault is usually the result of a blocked burner, a faulty spark generator, a blocked pilot jet or an ignition lead or probe fault. 

What to do next: You should call a Gas Safe registered heating engineer and tell them the error code on your boiler display panel. They will then come out and assess your boiler to look for any issues mentioned above. If the cause is a blocked or damaged component, the engineer will either fix the problem, replace the part or even recommend you get a new boiler. 

4. Fan fault

Your Ariston boiler relies on its fan to push harmful gases away from the boiler and up the flue. If the fan develops a fault, it will cause your boiler to stop working, and an error code may appear on the display panel. The issue could be a loose component, a blockage, a broken fan, or incorrect fan settings.  

What to do next: A fan fault requires a Gas Safe registered engineer to inspect your boiler and get to the bottom of the problem. They may only need to clear a blockage or sort out a loose component, but the worst-case scenario is needing a new fan. Boiler fans can be expensive to replace and, depending on the age of your boiler, may not be worth replacing. If your Ariston boiler is old and inefficient, your engineer may suggest getting a new one installed. 

5. Printed circuit board error

The printed circuit board (PCB) is a vital and expensive boiler component that acts as the brain of your boiler and controls all actions to ensure your appliance works properly. If there is a fault with the PCB, the error code 303, 305, 306 or 307 should appear on the display panel, and you may need to get an engineer to replace the PCB. 

What to do next: You should never attempt to fix a faulty PCB, meaning you need to get a Gas Safe registered engineer to take a look at your boiler and identify the cause of the issue. If your engineer cannot repair the problem and you require a replacement PCB, you’re looking at spending anything upwards of £500 to replace it.