10 Signs You Need an Emergency Plumber Right Now

Not every plumbing problem is an emergency — but when it is, every minute counts. Calling an emergency plumber at the right time can prevent thousands of pounds of property damage. This guide helps you recognise which problems need immediate action and which can wait until morning.

Call an Emergency Plumber Immediately If You Have Any of These

1. Burst Pipe

A burst pipe can release hundreds of litres of water per hour. Turn off the main stopcock immediately (usually under the kitchen sink or where the supply enters the house), then call an emergency plumber. Don't wait. See our full guide: Burst pipe in London — exactly what to do.

2. Major Leak You Cannot Stop

If water is actively flowing and you can't isolate it at a local valve, turn off the main stopcock and call immediately. Water damage to London properties can escalate quickly — saturated plasterwork, damaged floors, and short-circuited electrics can cost tens of thousands to repair.

3. Suspected Gas Leak

If you can smell gas (a rotten egg or sulphur smell): don't turn any switches on or off, don't use your phone indoors, don't light anything. Leave the property, leave the door open, and call the National Gas Emergency line on 0800 111 999 (free, 24/7). Only return when given the all-clear.

4. Sewage Backing Up Into Your Property

Raw sewage backing up through toilets, sinks, or floor drains is a serious health hazard as well as a plumbing emergency. Do not attempt to use any plumbing until it has been resolved. Call a plumber immediately.

5. No Heating or Hot Water in Winter (Vulnerable Household)

If a child, elderly person, or someone with a medical condition is in the property with no heating in cold weather, this is a genuine emergency. London emergency plumbers are available 24/7 for urgent boiler faults. See: No hot water — causes and fixes.

6. Overflowing Toilet with No Shutoff

If a toilet cistern won't stop filling and water is overflowing, and you cannot stop it via the internal float valve or an isolating valve, call an emergency plumber. Continuous overflow can cause significant water damage through ceilings and floors.

7. Water Coming Through Your Ceiling

Water dripping or pouring through a ceiling means a pipe above has failed — in your own flat or from a neighbour above. Turn off electricity in the affected area at the fuse box, contain the water with buckets, and call a plumber immediately. Also inform your upstairs neighbour.

8. Boiler Making Banging, Hissing, or Popping Sounds

Unusual loud noises from a boiler — particularly hissing, which can indicate a steam or pressure problem — should be taken seriously. Turn the boiler off and call a Gas Safe engineer. Do not ignore these sounds.

9. Complete Loss of Water Supply

If you suddenly have no water and your neighbours are unaffected, the problem is within your property. This may indicate a burst supply pipe or a problem with the internal stopcock. Call a plumber promptly — you cannot function without water.

10. Frozen and Burst Condensate Pipe

In very cold weather, the condensate pipe from your boiler can freeze. If it bursts rather than just freezes, the boiler will need immediate attention from a Gas Safe engineer to prevent further damage.

Issues That Can Wait Until Morning (and Save You Money)

Calling an out-of-hours emergency plumber costs 30–50% more than a daytime callout. These problems are genuinely annoying but do not require immediate action:

• Dripping tap — turn off the isolation valve beneath the tap if needed, call in the morning
• Slow-draining sink — try a plunger yourself; if that fails, book a daytime appointment
• Toilet running continuously — turn off the isolation valve on the toilet's supply pipe; book in the morning
• Boiler fault (no heating) in mild weather — check pressure and reset first; if not urgent, wait for a morning appointment
• Minor, controlled leak — use a bucket to catch water and turn off the supply if possible; book morning repair

What to Do While Waiting for the Emergency Plumber

1. Turn off the water supply at the main stopcock (for leaks and burst pipes)
2. Turn off the boiler (for gas faults or if pipework to the boiler is leaking)
3. Switch off electricity in flooded areas at the fuse box
4. Move valuables and electronics away from water
5. Take photos of the damage for insurance purposes
6. Open windows if you suspect a gas leak

See also: Leaking pipe — what to do before the plumber arrives.

How Much Does an Emergency Plumber Cost in London?

Emergency out-of-hours callout fees in London typically range from £100–£200 plus £90–£150/hr for labour. Daytime emergency callouts are cheaper at £80–£150. See the full breakdown: How much does a plumber cost in London?