Ariston Boiler Error 104

What is the fault of the 104 error Ariston affecting your boiler?

The error code 104 on the Ariston boiler means that there is insufficient water circulation in the heating circuit. This can cause the boiler to lock for safety and not turn on, or to turn off shortly after running. The error code 104 usually appears along with the message "Fill system", which indicates that the water pressure is too low and it is necessary to refill the circuit.

The error code 104 on the Ariston boiler can have several causes, including the following:

• A water leak in the heating circuit, which can be due to a break or a poor connection of some element, such as a radiator, a valve or a pipe.
• A faulty expansion vessel, which does not absorb the expansion of water when heated and causes an increase in pressure and loss of water through the safety valve.
• A damaged or blocked circulation pump, which does not pump the water through the circuit and generates a lack of flow.
• A three-way valve stuck or damaged, which does not correctly switch between the domestic hot water mode and the heating mode, and hinders the passage of water.
• An obstructed or broken automatic air vent, which does not eliminate the accumulated air in the circuit and causes a decrease in pressure and poor performance of the boiler.

How to solve the 104 error of the Ariston boiler?

The error code 104 on the Ariston boiler can be solved if you follow the steps that we are going to leave you below:

1. Restart the boiler: The first thing you should do is try to restart the boiler by pressing the corresponding button on the control panel. This can cause the system to reset and start working properly again. If you don't know how to restart your boiler model, check the instruction manual or contact the official technical service.
2. Refill the circuit: If the error code 104 continues to appear after restarting the boiler and the message "Refill system" is displayed, you should check the pressure gauge and refill the circuit if it is below 1 bar. To do this, you must open the valves located under the boiler until the pressure reaches between 1 and 1.5 bar, and then close them. If you don't know how to refill your boiler model, check the instruction manual or contact the official technical service.
3. Check for leaks: If after refilling the circuit you notice that the pressure drops quickly again, there may be a water leak somewhere in the circuit. You should review all the elements of the system, such as radiators, valves, and pipes, and locate and repair the leak.
4. Change the expansion vessel: If after refilling the circuit you notice that the pressure rises too much and the safety valve is activated, there may be a problem with the expansion vessel. This component has a membrane that can puncture or deteriorate over time, and prevent the vessel from fulfilling its function of absorbing the water expansion. You should change the expansion vessel for a new one and adjust its pressure according to the manufacturer's specifications. If you don't know how to do it or don't have the right tools, contact a qualified professional.
5. Unblock the circulation pump: If after refilling the circuit you observe that the pressure is correct but the boiler is still not working, there may be a problem with the circulation pump. This component can get blocked due to dirt accumulation or prolonged disuse, and stop pumping water through the circuit. You should unblock the circulation pump by opening the screw on its front and turning the shaft with a screwdriver or Allen wrench. If you don't know how to do it or don't have the right tools, contact a qualified professional for this task.
6. Repair or replace the three-way valve: If after refilling the circuit you observe that the pressure is correct but the boiler only works in one of the modes, there may be a problem with the three-way valve. This component can get stuck or damaged by corrosion or wear, and stop switching between domestic hot water mode and heating mode. You should repair or replace the three-way valve with a new one and check that it works correctly.
7. Clean or replace the automatic air vent: If after refilling the circuit you observe that the pressure is correct but the boiler makes strange noises or doesn't heat well, there may be a problem with the automatic air vent. This component can get blocked or broken due to dirt or rust, and stop removing air from the circuit. You should clean or replace the automatic air vent with a new one and check that it works correctly.
8. Repeat all the above steps if the problem persists: If after performing all the above actions the error code 104 still appears on the screen, you should repeat all the steps from the beginning and make sure that you have correctly performed each of them. If you still can't solve the problem, there may be a more serious fault in the boiler that requires professional intervention.
9. Go to the official Ariston technical service to solve the problem: If after repeating all the above steps the error code 104 still appears on the screen, you should go to the official Ariston technical service to solve the problem. They will be able to diagnose and repair the fault with the guarantees and original spare parts from the manufacturer.

To solve the error code 104 on the Ariston boiler you should follow these steps:

• Restart the boiler
• Refill the circuit
• Check for leaks
• Change the expansion vessel
• Unblock the circulation pump
• Repair or replace the three-way valve
• Clean or change the automatic air vent
• Repeat all the above steps if the problem persists
• Go to the official Ariston technical service to solve the problem

We hope this article has been useful for you to understand what the error code 104 on the Ariston boiler is and how to solve it. Remember that to avoid these types of problems, it is advisable to carry out regular maintenance on your boiler, following the manufacturer's recommendations and hiring a qualified professional.