Ariston 104 Fault

Ariston 104 Fault

In the Ariston boiler system, the error code 104 indicates a low water pressure fault. This is when the heating system drops below the minimum necessary threshold, adversely affecting efficient and safe functioning of the boiler.
Error Code 104 Causes

When there are Heating System Leaks: Any leaks even those considered as minor can cause a slow loss of water that leads to low pressure within the system.

Radiators Recently Bled: By filling up radiators with air immediately after bleeding them, their overall system pressure can be decreased.

Defective Pressure Release Valve: Defects in pressure release valve may allow water to leak out thereby causing a drop in pressure.

Natural Loss of Pressure Over Time: It’s typical for boilers to lose water with time and thus require occasional refilling.

Solving Error Code 104

Check if you have any visible leaks: Examine your radiators and pipes as well as your boiler for any signs of leaking. Once you identify any leakage identified , it should be repaired promptly .

Re-Pressurize Your System: Mostly, you can re-pressurize your own central heating by using its filling loop. You do this by opening valves on this loop while allowing more water into it until checking that gauge reads at recommended limits usually around (1-1.5 bar) then closing them off again. The instructions on how to do this should be found in your boiler’s manual.

Bleed Your Radiators: If you haven’t recently checked your radiators for trapped air which might be contributing to heat or pressure problems, then bleed some air from them before repressurizing the system

Examine PRV operation: If there is uncontrolled leakage from discharge pipe (constant dripping), it would be best if an expert was consulted on how to repair or replace that valve

Resetting of Boiler Switching Off At Low Pressure Condition : After resolving the problem of low pressure, one should reset the boiler to clear the error codes and confirm whether it is operating normally.


In many cases, the Ariston error code 104 can be fixed by repressurizing the boiler system and checking for leaks. Checking your boiler’s pressure gauge regularly can help you identify low pressure situations that may occur over time. For long-term or recurrent issues, you need to contact professionals who will diagnose any problems with your heating device and suggest appropriate remedies.