Wear and tear and lack of maintenance are just two of the many factors that cause a water leak from the boiler. It is a problem that must be addressed immediately to prevent it from getting worse and to continue using its functions.

What to do when the boiler is leaking water

Before fixing a boiler water leak, it is important to identify the cause of the unexpected issue. There can be various reasons for the leak.

• The boiler might leak water even when it is off. In this case, seals and fittings should be carefully checked, and it should be ensured that there is no breakage in the pipes.
• If the drip is slow, but constant, it is very likely that the problem comes from the drain pipe or the connected tap. Then, proceed to replace them and assess the state of their seals.
• However, if the leak is substantial, then it is related to a pressure problem. When the pressure is too high, the relief valve opens to allow excess water to overflow. The level should be set between 1.2 and 1.5 bar: just observe the values indicated by the pressure gauge for monitoring.
• Conversely, it can happen that a water leak stems from too low pressure. This is another case where, for example, the boiler loses water while off: there is a lockout and the pressure drops. To intervene, air can be removed from the system by operating the radiator bleed valve.

The best solution is to rely on the expertise of a specialised technician, considering the many reasons behind the malfunction and the need to remedy it promptly.

Why is the relief valve leaking?

If the boiler is leaking water from the bottom, it most likely indicates that the source is the safety valve, which regulates the pressure and is also referred to as the relief valve. Since it's meant to regulate pressure, water leaking from this valve signals that the issue is related to the pressure level.

Considering that the optimal range is between 1.2 and 1.5 bar, if the pressure reaches too high a value (exceeding the maximum limit of 3 bar), the valve releases excess water to maintain the internal circuit's good condition and prevent the situation from worsening.

The impact of limescale forming in the pipes and coming into contact with the seals, compromising their integrity, should not be underestimated.

That is why maintenance and cleaning of the boiler are fundamental steps to preserve its operating condition and avoid unpleasant surprises.

How much does it cost to repair a leaking boiler?

As previously mentioned, there are multiple causes of a water leak, which affects the cost of intervention and any components that may need to be replaced.

• The source of the problem may depend on the expansion tank, a component that maintains stable pressure. Specifically, it absorbs the increase in pressure caused by the rise in temperature and water volume. If the internal membrane of the expansion tank, which enables the absorption function, is punctured, it fails to contain and control the increase in pressure. This usually happens when the boiler is in operation and not when it is off.
• Alternatively, the heat exchanger might be punctured, through which the water of the heating circuit and the water for producing domestic hot water flow without coming into contact. If the internal plates of the exchanger are punctured, the two circuits mix, leading to an increase in pressure. The relief valve then activates to bring the pressure level back to an optimal range, namely under 2 bar.
• There is also the possibility of a malfunction in the fill valve, which allows water to enter from the water network to increase pressure when it is too low. However, if the valve does not perfectly close once shut, water continues to slowly flow into the boiler. Limescale and buildup affect the state of the valve and its seals.
• Limescale can also compromise the internal part of the valve, leading to the formation of water droplets leaking from the component. This is a warning that it is time to replace the safety valve.

Who should I call when the boiler is leaking water?

The boiler can be considered the heart of the heating system and provides hot water for household needs.

In the event of a leak that compromises its regular operation, the only solution to consider is the intervention of a specialised technician.

Thanks to their expertise, they can indentify the cause of the leak and act as soon as possible. Unskilled hands, on the other hand, significantly increase the likelihood of worsening the situation, which could completely compromise the functioning of the heat generator.