How to solve boiler lockout due to limescale

The boiler is an essential part of a home heating system. It is the boiler that supplies radiators or obtains domestic hot water. If you have noticed that the hot water jet is not as strong as the cold water jet and the temperature is not ideal, or even that the water is not heating up at all, then there may be a problem caused by limescale. This is one of the reasons that could cause your boiler to go into lockout.

A boiler goes into lockout when there is something preventing it from functioning properly. This activates a safety system, which locks the appliance to prevent more serious damage. Water containing large amounts of limescale can cause problems to plumbing and the boiler, causing blockages and lockouts.

Why does limescale cause a boiler to lockout?

Limescale obstructs the passage of hot water, causing a reduction in flow and, as a result, when the flow is insufficient, the boiler fails to switch on for safety and goes into lockout. This is one of the most frequent causes, especially in areas where the water is denser and richer in lime.

How to prevent boiler lockouts caused by limescale

The most effective way to prevent boiler lockouts caused by limescale is to carry out regular maintenance with chemical flushing of the system. If this is not carried out regularly, we also need to pay attention to any noises made by the boiler. If the noise is similar to that of water bubbling, or gurgling, there may be a malfunction in the primary exchanger, which then leads to a boiler lockout.

The heat exchanger is a fundamental part of the boiler with the role of taking the heat from the flame and transferring it to the water itself. With time and wear, however, limescale can clog and obstruct water flow, settling in the channels through which it passes.

When this happens, the water heats up inside the boiler and is unable to escape, so you automatically hear the noise we are talking about, because the water really is boiling inside the appliance.

In this case, the intervention of a specialist service engineer is required to check the water flow through the circuit, the absence of obstructions and finally, to assess whether it is necessary to change the primary exchanger.  

Solution to boiler lockouts caused by limescale

In the event that the boiler fails due to the presence of limescale, we advise you to call in a specialist service engineer, who will clean the exchanger using an acid fluid capable of dissolving the limescale without ruining the system.  

It is also possible to fit a limescale filter (polyphosphate dosing unit) or a sludge filter to the boiler to reduce the problem of limescale build-up and thus limit the likelihood of the boiler going out of operation.

Rely on specialist installation or service engineers, such as Enel Partners who can assist you with boiler repair and maintenance.