What Counts as a Leak Emergency?
Not every leak is an emergency, but some absolutely are. Understanding the difference helps you respond appropriately and helps us prioritise our London callouts effectively.
A genuine emergency is any situation where water is actively flowing and you cannot stop it, where there is a risk to the electrical supply or the structural integrity of the building, or where a property is becoming uninhabitable. Examples include a burst pipe with water pouring through a ceiling, a major heating system failure with water flooding from radiators or pipework, a water main leak that cannot be isolated, or water approaching electrical fittings, consumer units, or sockets.
Situations that are urgent but not immediately dangerous include steadily worsening damp patches, a boiler that keeps losing pressure, an unexplained increase in your water bill, or a slow drip from an unknown source. These need attention soon, but a next-day appointment is usually appropriate rather than a midnight callout.
What to Do While Waiting for the Engineer
If you have called for emergency leak detection, there are several things you should do while waiting to limit the damage.
Turn off the water supply if you can. The main stopcock is usually under the kitchen sink, in a downstairs cupboard, or sometimes in the cellar in older London properties. If you live in a flat, there may be an isolation valve for your unit on the riser in a communal cupboard. Turn the stopcock fully clockwise to shut off the supply. If the leak stops, you know it is on the mains supply rather than the heating system.
If the leak involves the heating system, turn off the boiler and the central heating. The leak may stop or slow significantly once the circulation pump is off and the system pressure drops. Do not drain the heating system unless a qualified person advises you to, as this can introduce air and cause further problems.
Turn off the electricity to any affected areas if water is near electrical fittings. Do this at the consumer unit by switching off the relevant circuit breaker. If you are unsure which circuit is which, and water is actively dripping near sockets or lights, switch off the main breaker. Your safety is more important than your convenience.
Move valuables away from the affected area. Place buckets or containers under drips. If water is coming through a ceiling, it can help to make a small hole in the plasterboard to let water drain in a controlled way rather than spreading across the ceiling and bringing the whole lot down. Use a screwdriver rather than anything that could damage pipes above.
Take photographs and video of the damage. This is essential for insurance claims. Document the water flow, the affected areas, any possessions that have been damaged, and any action you have taken. Insurers look favourably on policyholders who take reasonable steps to mitigate damage.
When the Engineer Arrives
Our emergency engineers arrive with a full complement of detection equipment and follow a systematic process to locate the leak as quickly as possible.
Initial assessment: The engineer will ask you to describe what happened and when, examine the visible damage, and assess the immediate risks. They will check whether you have managed to isolate the water supply and confirm whether the leak is on the mains cold water, hot water, heating system, or waste pipework. This initial assessment typically takes ten to fifteen minutes and guides the choice of detection method.
Detection survey: Using the appropriate combination of thermal imaging, acoustic listening, tracer gas, and moisture mapping, the engineer will systematically work to pinpoint the leak. In an emergency, the priority is locating the leak so it can be isolated or repaired. The engineer may start with thermal imaging to get a broad picture of where moisture is present, then use acoustic equipment to identify the precise leak point.
Confirmation: Once the suspected leak location is identified, the engineer will explain their findings and the evidence supporting them. In some cases, a small area of access may be needed to visually confirm the leak, particularly if the leak is in a floor void or wall cavity. The engineer will discuss this with you before doing any opening up.
Temporary repair or isolation: Many of our engineers can carry out temporary repairs or isolate the leaking section of pipework to stop the water flow. This is not always possible, particularly with complex commercial heating systems or buried water mains, but where it can be done it prevents further damage while a permanent repair is arranged.
Typical Timeline
For a straightforward emergency in a London residential property, the entire process from arrival to leak location typically takes between one and two hours. Complex scenarios involving multiple possible sources, large commercial buildings, or leaks in particularly inaccessible locations may take longer.
After the emergency visit, you will receive a written report, usually within twenty-four hours, documenting the findings. This report can be used for your insurance claim and provided to whichever contractor carries out the permanent repair.
After the Emergency
Once the immediate crisis is dealt with, there are several things to arrange. Contact your insurer to report the incident. Arrange a permanent repair with a qualified plumber or heating engineer. Begin the drying process for any water-damaged areas. Obtain quotes for any reinstatement work such as replastering or redecorating.
If your home insurance includes trace and access cover, the cost of the emergency detection visit may be recoverable. Keep all invoices and correspondence, as your insurer will need these to process the claim.