Water Leaks In Your Heating System: What To Do First

Most commonly under the kitchen sink, though it can also be under the stairs, in a utility room, or near where the supply pipe enters the property. Worth locating and testing it now, before you need it in a hurry.

The stopcock controls the incoming mains supply, so it stops cold water to taps and the system’s filling point, but it won’t immediately drain your sealed heating system. It does mean you can’t top up boiler pressure while it’s off, so don’t leave it closed long-term without getting the leak fixed.

Generally yes for a short period if the leak is minor and contained, but running the system keeps pressure on the leak point and can make it worse. Best to get it looked at promptly rather than running as normal for an extended time.

Yes — a hidden leak running for weeks is one of the most common causes of damp patches and mould, particularly under floors or behind walls where it isn’t immediately visible.

Some dripping is entirely normal, especially in cold weather — it’s the boiler’s waste water draining away. It becomes a concern if it’s pooling excessively, freezing and blocking the pipe, or coming from anywhere other than the intended outlet.

Not immediately dangerous, but it will worsen over time and can eventually stain or damage flooring. It’s usually a quick fix — often just tightening or replacing a compression fitting.

Condensation appears as a fine film of moisture on cold surfaces like pipes or windows and evaporates on its own. A leak produces standing water, a growing stain, or a consistent drip that doesn’t go away with ventilation.

This depends entirely on your policy and the cause of the leak, so we’d always recommend checking directly with your insurer rather than assuming either way. Photographing the leak and damage as soon as you find it is worth doing regardless.

Yes — a leak anywhere in a sealed system will cause pressure to drop gradually, which is often how leaks get noticed in the first place rather than by seeing the water itself.

In a flat or converted property, water on a ceiling or wall doesn’t always originate directly above — it can travel along joists or through shared walls. If you can’t find an obvious source on your own pipework and appliances, check with neighbours or building management, as tracing it may need access to more than one property.

As soon as you’ve isolated it — unless it’s actively spreading or near electrics, in which case call immediately rather than waiting. Even a slow leak is worth booking within a few days rather than letting it run indefinitely.