10 Common Ariston Boiler Problems & How to Fix Them

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Boiler breakdowns can occur due to many issues including wear and tear, pressure issues and part failures. Some may be minor issues that can be simply and safely resolved yourself, where other break downs might require expensive parts being replaced, and therefore a new boiler may be the most sensible option.

Ariston boilers are well known for being durable and reliable however issues will still occur from time to time.

In this post, we will run through the most common problems that have been reported with Ariston boilers including methods of identifying the issue concerned and also providing details of how to fix the issue. We will also highlight the scenarios when it is best to escalate to a specialist Gas Safe engineer.

Most Common Ariston Boilers Issues

Issue 1 – Low Water Pressure

Low water pressure can be a common complaint no matter the brand of the boiler.

On an Ariston boiler, low water pressure may be represented by error code I08 within the display panel and is commonly caused by a leak either within the boiler itself or throughout the heating system.

The first step in this scenario is to attempt to repressurise the boiler by using the external filling loop to increase pressure to the suggested setting of 1.3 bar. To do this, check the re-pressurising instructions within the boiler’s manual.

Hopefully, this should clear the error message and re-start the boiler however it may only resolve the issue temporarily, if so, a visual check would need to take place to try and spot any signs of a leak. If a minor leak is found it can be fixed yourself by applying some DIY sealant to the pipework however if there is any doubt in the location or size of the leak, always seek the advice of a specialist engineer to review the boiler and heating system.

Related boiler problems:

Issue 2 – No Pilot Light

Pilot lights are essential for boilers to function and there can be a number of reasons behind the light going out and not restarting.

On an Ariston boiler, when a pilot light goes out the display panel may show error code 501.

A common cause of the pilot light going out on an Ariston boiler is a blockage within the pilot jet resulting in the gas not reaching the pilot light therefore stopping the ability to extinguish.

If the error code appears on the display panel when the pilot light is still lit, the flame sensor could have developed a fault.

Any concern with a pilot light will require a call out from a Gas Safety engineer. In the scenario where the pilot light is blocked, the engineer will perform a clean and reinstall it however if there is a fault, a replacement part will be required, however, this should not be too costly.

Issue 3 – Air Pressure Switch Fault

Another common problem with Ariston boilers is the development of a fault with the air pressure switch. An air pressure switch monitors that the dangerous gasses created by the boiler are pushed up through the flue pipe and away from the property.

Obviously, the air pressure switch performs a crucial safety check and therefore if the system isn’t working correctly, the boiler will lockout and not re-start as a safety mechanism.

On most Ariston boiler models, the error code related to the air pressure switch is E34.

A Gas Safe engineer would need to be called out to confirm the diagnosis that the fault is with the air pressure switch. If so, a replacement part should be reasonably quick, easy and cost-effective however if the air pressure switch is not faulty there could be a more serious issue such as a faulty printed circuit board or PCB – see issue 6.

Issue 4 – A Broken Fan

The fan inside a boiler undertakes an important job of expelling the gases towards and through the flue. If the fan has stopped working the boiler will lock out and not re-start for safety purposes. On most Ariston boiler models, the error code in relation to the fan, A41, will be shown on the display panel. In addition, the boiler unit would be silent without the low humming noise that is present when the fan is operating.

A Gas Safe engineer would be required to replace a fan.

Issue 5 – Fan Running too Slow

Another matter that can develop with boilers is that the fan speed drops so that it runs too slowly. The result is the same as a broken fan scenario where the boiler will lock out and not re-start for safety purposes as the gases are not pushed into the flue. Often on Ariston boilers, the display panel will show the error code 604 when the fan speed is a concern.

Sometimes the slower operating speed can be due to a blockage or loose part which may be a fairly easy task for a specialised engineer to resolve.

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Issue 6 – Faulty Printed Circuit Board

A boilers printed circuit board or PCB, is the electronic motherboard of the boiler that is crucial to the functioning of the boiler as it enables communication between each of the components.

Due to the nature of such a complex part, there are a number of error codes that could be shown on the boilers display panel related to the PCB as follows; 301, 302, 303, 304, 305, 306 and 307.

If any of these codes are displayed you could require a new PCB, which are very expensive boiler parts, often around £500, and therefore depending on the age of the boiler and the proposed cost to repair, it may be more cost-effective to replace the whole boiler.

In the scenario where your Ariston boiler displays one of these codes, you will require a call out from a specialised engineer to confirm the issue and provide quotes either for a replacement part or a new boiler.

Issue 7 – Ignition Fault

Another common fault with Ariston boilers are ignition issues, often represented by error codes 5P1 or 5P2 displayed in the panel.

Ignition problems can be caused by a number of issues including a faulty fan, a blocked ignition jet caused by a build-up of debris, faults with the spark generator or an intermittent gas supply.

In any case, a call out from a specialised Gas Safe engineer will be required, who will be able to ensure that blockages are cleared and attempt to reignite the boiler. If there are faults with the ignition component, the cost of replacing this part shouldn’t be too expensive.

Issue 8 – Lack of Circulation

Lack of circulation can occur with Ariston boilers when there is a fault with the heating pump or a blockage within the system, often communicated by any error code between 103 and 108 being shown on the display panel. Any matters concerning the heating pump within a boiler will require a visit from a specialised Gas Safe engineer to investigate further.

If a build-up of sludge is the culprit a system flush can be undertaken, however, if the matter is a fault within the heating pump itself, the part will likely need replacing.

Boiler brand faults: 

Ariston Boiler Problems Summary

An array of faults can occur with Ariston boilers with some more simple to overcome than others. However, if there is any doubt regarding the matter, always seek professional advice to confirm the diagnosis safely and quote for replacement parts when needed.

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