When to Call a 24/7 Plumber (and When You Can Wait Until Morning)

It's 1am. Something's wrong with the plumbing. You're trying to work out whether to phone an emergency number right now and pay unsocial-hours rates, or go back to bed and sort it in the morning. This guide exists to help you make that call honestly. If you already know you need someone now, skip straight to our 24/7 emergency plumber London dispatch line.

The short version: a proper emergency costs money to fix at 1am and costs a lot more if you leave it. A non-emergency costs 30-50% less at 9am than it does at 1am, and nothing bad happens if you wait. Knowing the difference saves you £100-£200 a year in avoidable premium call-outs.

What Counts as a Real Plumbing Emergency?

A real emergency meets one or more of these tests:

• Damage is actively happening. Water is pouring into the property, sewage is backing up, gas is leaking into a room.
• Damage will get materially worse in the next 6-8 hours. A burst pipe you can't isolate, a ceiling beginning to sag, a leak near electrics.
• Safety risk. Gas smell, carbon monoxide symptoms, flooding near electrical circuits, freezing conditions with vulnerable people in the property.
• Loss of essential service. No water at all in the property, no heating in freezing weather with a baby or elderly person, only toilet blocked with no alternative.

If none of those apply, it almost certainly isn't an emergency in the pricing sense. It's a problem. Problems can wait 6-8 hours. Emergencies cannot.

Issues That Need Immediate 24/7 Response

Burst pipe (any size, anywhere)

A burst pipe under mains pressure puts out 5-15 litres of water per minute. A single hour of unchecked flow can destroy plaster ceilings, ruin hardwood floors, and write off electrical sockets. Even if you isolate the stopcock and stop the flow, you need a plumber to make a proper repair before you can turn the water back on - and you do need the water back on for drinking, washing, and flushing. See our dedicated burst pipe repair London service page for the full process on a priority-dispatch job.

Scenario: You wake at 2am to water dripping through the kitchen ceiling from the bathroom above. That's emergency territory. Turn off the stopcock, then call a 24/7 plumber.

Mains-pressure leak that can't be isolated

Your stopcock is seized, broken, or non-existent (common in older London properties). You can't turn the water off at all. The flow is causing progressive damage. Call now.

Gas smell

Turn off the gas at the meter (quarter-turn lever to perpendicular), open windows, leave the property, and call the National Gas Emergency Service on 0800 111 999 first. They attend free of charge and make the supply safe. After they've attended, call a Gas Safe registered plumber to fix the underlying fault.

Sewage backing up into the property

Waste water coming up through shower drains, toilets, or bath plugholes indicates a severe blockage in the soil stack or external drain. This is a health emergency - waste water contains pathogens and should not be left in the property. Stop using water immediately (no more flushing, no more running taps) and call a plumber with drain-clearing capability.

No heating in freezing weather with vulnerable people

A boiler breakdown in sub-zero temperatures when there's a baby, an elderly person, or someone medically vulnerable in the property is an emergency. Portable electric heaters help short-term but don't reach the whole property. For a fit adult household with extra blankets, the same fault can usually wait until morning at standard rates.

Only toilet is blocked

If the property has multiple toilets, a single blockage can wait. If it's the only toilet and it won't flush at all after plunging, call a plumber. Having no toilet is a genuine hygiene emergency, especially with children in the property.

Flooding near electrics

Water inside a consumer unit, pouring through a light fitting, or pooling near sockets is a fire and electrocution risk. Turn off the consumer unit (main switch) if safe to do so, then call an emergency plumber. In serious cases, call the fire service as well - they'll isolate the electrics.

Complete loss of water supply

Check with neighbours first - if they have water, the fault is internal to your property. A ruptured mains pipe underground or a completely failed internal supply is an emergency. If neighbours don't have water either, call Thames Water or your local supplier on 0800 316 9800; it's their problem to fix.

Issues That Can Wait Until Morning

Dripping tap

Look under the sink for the isolation valve (slotted brass screw on the supply pipe, usually within 30cm of the tap). Turn it clockwise 90 degrees to shut off that single tap. Book a standard appointment in the morning. Emergency rate: £150-£250. Standard rate: £80-£150.

Slow drain

Annoying, not urgent. Try a plunger, try a drain cleaner (Mr Muscle, HG Liquid Drain Cleaner), or leave it and book a plumber in the morning. The exception: if sewage is rising out of the drain, that's the emergency above.

One radiator not heating

Try bleeding it first (most common cause is trapped air). If that doesn't solve it, check the lockshield valve is open and the TRV isn't stuck. If the rest of the heating works, this is a scheduled job, not an emergency.

Running toilet

The cistern keeps filling. Annoying, but the water is going back into the system rather than damaging the property. Turn off the isolation valve behind the toilet to stop the refill, leave it overnight, book a plumber to fix the fill valve or flush valve in the morning.

Boiler lockout with backup heating

Boiler shows an error code and has shut down. If you have backup electric heating, extra blankets, and no vulnerable people, this can wait. First try a reset (usually a button on the boiler control panel) and check the pressure gauge - repressurising a low-pressure system often fixes it (instructions here). If the lockout returns, book a morning call-out.

Low water pressure

Check the stopcock is fully open (often the cause after renovation work). If there's still low pressure everywhere in the property, it's likely a mains issue or a partially blocked supply. Not urgent unless it's affecting the boiler.

Slow toilet fill

Toilet refills slowly after flushing. Fill valve is dirty or failing. Book a morning appointment.

Small under-sink leak you can catch in a bowl

Place a bowl underneath, put towels down, turn off the isolation valve if you can find one. If the leak rate is slow enough that a bowl will last 6-8 hours, this is a morning job.

Temporary Fixes to Do While You Wait

These four containment actions let you stop damage progressing long enough to either wait until morning or buy time for the plumber to arrive.

1. Turn off the internal stopcock

Location: usually under the kitchen sink, sometimes in a utility room, occasionally in a hallway cupboard. It's a brass tap or lever. Turn clockwise to close. This shuts off ALL water to the property. Good for: any burst pipe, major leak, or mains pressure failure.

If the stopcock is seized (very common in older London properties), don't force it - you'll snap the spindle and make things worse. Call the plumber and keep containing the leak by other means.

2. Turn off gas at the meter

Location: external meter box, usually near the front door. The lever handle should be in line with the pipe when on, at 90 degrees to the pipe when off. Turn it perpendicular. Gas is off.

Do this immediately for any gas smell, then call 0800 111 999. Do not turn electrics on or off, don't use light switches, don't use your phone inside the property - go outside to call.

3. Isolate a single tap or appliance

Look at the pipe feeding the tap, washing machine, dishwasher, or toilet. Within 30cm you should see a slotted brass screw on the pipe - that's the isolation valve. Turn it clockwise 90 degrees with a flathead screwdriver. That single appliance is now isolated while the rest of the water supply continues to work.

Good for: dripping taps, a single leaking appliance, a running toilet.

4. Contain a slow leak with towels and buckets

For any drip that isn't catastrophic:

• Place a bucket or large bowl directly under the leak.
• Lay old towels around it to catch splashes.
• If water is coming through a ceiling, pierce a small hole at the lowest point of the bulge with a screwdriver, put a bucket under it. This controlled release prevents the ceiling collapsing suddenly under the weight of the water.
• Photograph the leak before containment. Useful for insurance.

How to Find a Trusted 24/7 Plumber

At 2am, your decision-making is compromised. You're stressed, tired, and water is doing something it shouldn't. That's exactly when bad operators win. A few checks save you from the worst of them.

Landlords dealing with a tenant-reported burst should also read our step-by-step burst pipe in a rental property landlord guide, which covers the first 10 minutes, Section 11 liability, and what the buildings insurer will and won't pay.

Do before you call

• Check reviews briefly. 60 seconds on Google. A real London emergency plumber will have dozens of real reviews, a mix of 4 and 5 stars (100% 5 stars is a suspicious pattern), and named reviewers not generic first names.
• Confirm a real phone number and London address. A contact page with a real London postcode is much more reliable than a company listed only via a contact form and a 0800 number.
• Avoid national lead-generation sites. Firms like some of the big UK lead-gen platforms take your details, sell them to 3-4 local plumbers, and the one that wins the lead pays a fee they recover from you. You pay 20-40% more than calling a local plumber directly.

Ask on the call

• "What's your fixed call-out fee including VAT, and what's included?" A specific number. Not "it depends" or "somewhere between".
• "When can the engineer arrive?" Honest answer: 45-90 minutes in London at night, longer in outer boroughs or during cold snaps.
• "Are you Gas Safe registered?" (Only if gas work is involved.) They should give you a number you can check on gassaferegister.co.uk.
• "Will I get a written quote before work starts?" Answer must be yes.

Green flags

• A human answers the phone, not a voicemail or automated menu.
• The person on the line knows specific plumbing terminology (stopcock, soil stack, circulator pump, combi vs system boiler).
• They give a firm price without hedging.
• They ask sensible questions (is the water isolated, where is the leak, what type of boiler).

Red flags

• Call goes to a generic call centre that takes details and "dispatches".
• The person on the phone won't quote a call-out fee.
• "Free call-out" followed by an unspecified hourly rate.
• Pressure to agree immediately ("we only have one engineer free, I need to know now").
• No VAT number on invoicing, cash-only payment demands.

For the full pricing breakdown on what a fair emergency call-out fee actually looks like, see our call-out fee guide.

What to Expect When They Arrive

A competent 24/7 London plumber arriving at your property will follow a predictable process. If the visit doesn't look like this, push back.

1. ID check on request. They should be willing to show ID, Gas Safe card if relevant, and company vehicle identification.
2. Assessment in 10-15 minutes. They look at the problem, trace the source, assess severity.
3. Fixed written quote before any work beyond the first hour. The quote should separate parts from labour and include VAT.
4. Your agreement before work starts. You have the right to decline the quote. You pay the call-out fee and they leave. You do not pay any "quote fee" on top.
5. Containment first, repair second. For a leak, the immediate priority is stopping active water loss - even if the final repair needs to be scheduled for daylight with parts on order.
6. Written record of work done. You get a written invoice listing what was repaired, what parts were used, labour time, and a workmanship guarantee (12 months is standard for emergency repairs).
7. Clean-up. The work area should be left clean. Towels, tools, and any debris removed.

Example scenarios

Burst pipe at 2am: Turn off stopcock. Call emergency plumber. Expect 60-90 minute response in London. Engineer arrives, assesses, quotes typically £150-£400 for repair. Repair takes 1-2 hours. Water back on by 5am. Total disruption: 3 hours, total cost including call-out: around £200-£450.

Dripping tap at 2am: Isolate the tap using the isolation valve under the sink (or the stopcock if you can't find one). Go back to bed. Call a plumber at 9am. Engineer arrives within a few hours, fixes it for £80-£150. Total disruption: 30 seconds of isolation, 45 minutes of plumber time. Saved versus emergency call-out: £100-£200.

No hot water at 2am: Check the boiler. Try a reset. Check the pressure gauge. If the heating still works, go to bed. Call in the morning. Emergency rate saved: £100-£150.

Flooding from ceiling at 2am: Turn off stopcock. Place buckets. Pierce ceiling bulge if it's starting to sag. Photograph for insurance. Call emergency plumber immediately. This is the scenario where paying the premium is absolutely worth it - every hour without intervention adds meaningful repair cost.

Frequently Asked Questions