Coffee Machine Leaking Water: Where It’s Coming From and How to Fix It

Posted by

August 7, 2026

On August 7, 2026

Last updated: August 2026

A puddle on the counter at 7am is not the way to start service. The good news is that most commercial coffee machine leaks come from five cheap, well-known places. You can narrow it down in about fifteen minutes, without taking a single panel off.

In 30 seconds:

Most leaks are a worn group head seal, a blocked drip tray waste, or a loose water inlet fitting — not a dead boiler.
A slow drip from the group after a shot is usually normal. A drip that never stops is not.
Water running down the outside of the portafilter during a shot means the group head seal has hardened.
Water pooling under the machine is nearly always waste, not fresh supply. Check the drip tray pipe first.
Steam, hissing, or water from a boiler seam means stop. Switch off and book an engineer.
Seals and shower screens are consumables. Budget to change them every 6 to 12 months on a busy bar.

Not sure whether the drip is a leak or normal behaviour? Work through the 15-minute leak check further down this page before you touch anything.

Why leaks get worse fast

A leak is water going somewhere it shouldn’t. That water lands on electrics, timber counters, or the floor behind the bar.

Left alone it also masks the real fault. A dripping group head that you ignore for a month can turn into a scored group and a much bigger bill.

Fresh water or waste water?

This is the single most useful thing to work out first. Fresh water comes in under mains pressure and keeps coming. Waste water only appears when you use the machine.

Waste leaks are usually cheap. Fresh water leaks are usually urgent.

Plumb-in or tank-fed?

Plumb-in machines take a 15mm cold mains supply through an isolator valve, and drain to a waste standpipe below the counter. Fracino Bambino, Velocino, Contempo and Romano machines are plumb-in.

Tank-fed machines carry their own water on board. The Cherub, Classico, Little Gem and Piccino all use a 3-litre internal tank. They can’t flood your bar, but they can still overflow a drip tray.

The honest summary. The biggest mistake we see is cranking the portafilter handle tighter to stop water squirting out of the group. That doesn’t fix the seal — it wears the group lugs and the handle, and turns a £10 gasket job into a workshop visit. If you have to force it, the seal has already gone.

Where the water is coming from: a quick lookup

Find your symptom in the left column, then read the matching section below.

What you can see	Most likely cause	Fix it yourself?
Water squirts round the edge of the portafilter mid-shot	Hardened group head seal or clogged shower screen	Yes, with the right part
Group drips a few times after the shot, then stops	Normal three-way valve release	Nothing to fix
Group drips constantly, machine idle	Sticking solenoid or debris on the valve seat	Clean first, then engineer
Puddle under the machine, no fresh water running	Blocked drip tray waste or a dropped waste pipe	Yes
Steady trickle into the drip tray while heating	Expansion or discharge valve doing its job	Usually nothing to fix
Water at the back near the inlet, worse in the morning	Loose braided hose or perished washer	Isolate, then engineer
Drip from the steam wand or hot water tap	Worn tap seat or valve seal	Engineer
Hissing, steam, or water from a boiler seam	Boiler or safety valve fault	Stop. Engineer only

1. Water leaking round the edge of the portafilter

What you see

Water sprays or dribbles from the join between the handle and the group
Shots run short or taste thin
The handle has crept further and further round to get a seal

What it usually is

The rubber group head seal. It sits in a groove inside the group and squashes against the rim of the portafilter basket.

Heat and coffee oils harden that rubber over time. Once it goes stiff it stops filling the gap, and pressurised water finds the easiest way out.

On a bar pulling 200 shots a day, expect to change the seal every 6 to 12 months. Quiet sites can stretch longer.

Check this before you buy a part

Wipe the rim of the basket and the group face — grounds on the rim break the seal on their own
Look at the shower screen. If it’s caked, water is being pushed sideways instead of down
Press the seal with a fingernail. Soft and springy is fine. Hard and shiny is done
Check you’re not overdosing. An overfilled basket lifts against the screen and forces water out

Watch out for

Fitting the seal upside down. Most have a chamfered edge that faces into the group. Fitted the wrong way it leaks straight away and you’ll blame the part.

2. The group head drips when the machine is idle

A few drips after a shot is normal. Your machine has a three-way valve that dumps the pressure out of the group when you stop the pump. That release is what gives you a dry puck, and a short dribble into the tray comes with it.

A drip that never stops is not normal. If the group is still weeping ten minutes after the last shot, water is getting past a valve it should not.

Try this first

Backflush the group with a blind basket and detergent, following your usual routine
Take the shower screen off, clean it, and check the dispersion block behind it
Run three flushes of clean water through the group afterwards

Coffee grounds and scale are the usual culprits. A grain of grit on a valve seat is enough to hold it open.

If it still drips after a proper clean, the solenoid valve or its seat needs attention. That’s an engineer job, not a bar job. Our guide to Fracino coffee machine servicing and warranty in the UK explains how the process works and what it costs.

3. A puddle under the machine

What you see

Water creeping out from under the base or the back feet
The drip tray is full or close to the brim
It only gets worse during service, not overnight

What it usually is

Nine times out of ten this is waste, not supply. The drip tray drains through a small pipe to a standpipe under the counter, and that pipe blocks with coffee grounds and milk residue.

Once it blocks, the tray fills, then overflows out of the back of the machine.

Fix it in five minutes

Pull the drip tray and grid out and empty them
Find the waste pipe at the back and check it hasn’t lifted out of the standpipe
Flush the pipe with hot water and a little detergent
Make sure the run falls downhill the whole way — a sagging loop holds water and blocks again
Check the standpipe is within about a metre of the machine and sits directly below it

Watch out for

A machine that’s been shuffled along the counter. Move it 200mm and the waste pipe can pop out of the standpipe without anyone noticing.

4. A trickle into the drip tray while the machine heats up

Switch a cold machine on and water expands as it heats. Warm-up takes roughly 15 minutes from cold on a Fracino.

Many plumb-in machines vent that expansion through a small pipe into the drip tray. A short trickle while the boiler comes up to temperature is usually the system doing what it’s designed to do.

When it isn’t normal

The trickle carries on all day, not just during warm-up
The gauge sits above the normal 1 to 1.2 bar working range
You can hear the pump cutting in and out with nobody using the machine

Boiler pressure that keeps climbing is a control fault, and the safety valve is the last line of defence. Fracino boilers are built for a maximum working pressure of 1.3 bar, with the safety valve lifting between 1.6 and 1.8 bar.

If the safety valve is lifting, switch off and call an engineer. Don’t trade around it.

5. Water at the back, near the mains inlet

This one only applies to plumb-in machines. The supply arrives as 15mm cold mains through a three-quarter inch isolator valve, then a braided flexible hose into the machine.

What you see

Damp at the back of the counter that’s there first thing, before you’ve made anything
A green or white crust on a brass fitting — that’s dried mineral, and it means a slow weep
Water tracking along the hose and dripping off the low point

What to do

Turn the isolator valve off at once — that stops mains water entering the machine
Dry the fitting, then turn the valve back on and watch it for a minute to confirm the source
If it weeps again, leave it isolated and get it looked at

A perished washer is a small part. A hose that fails at full mains pressure while the shop is shut is a very different day.

6. Drips from the steam wand or the hot water tap

Taps and steam valves have their own seals and seats. They wear because they get used hundreds of times a day and get slammed shut.

Before you call anyone

Purge the wand properly and wipe it after every jug — dried milk holds the valve off its seat
Close the valve firmly but don’t force it. Forcing wrecks the seat
Check the wand tip holes aren’t blocked, which raises back pressure

A wand that still weeps after a clean needs a new seal. That’s inside the valve body, so it goes to an engineer.

Weak steam alongside the drip points somewhere else entirely. If that sounds like your machine, read our fixes for a coffee machine with no steam or low pressure instead.

7. Tank-fed machines: overflow, not leaks

Tank-fed machines like the Cherub, Classico, Little Gem and Piccino hold about 3 litres on board. There’s no mains connection, so a real flood isn’t possible.

What you get instead is water on the counter from three places.

Overfilled tank — fill to the mark, not to the brim, or it spills as it warms
Full drip tray — there’s no waste pipe, so somebody has to empty it. Twice a day on a busy counter
Tank seated badly — push it fully home so the pickup tube seals

If you’re constantly emptying trays and refilling tanks, that’s a sizing problem rather than a fault. Our guide to what size coffee machine your coffee shop needs covers when to move up to a plumb-in two group.

How to find a coffee machine leak in 15 minutes

Do this before service, with the machine cold. You need kitchen paper, a torch and a dry cloth.

Dry everything. Wipe the machine, the counter and the floor behind it until nothing is damp. You can’t trace a leak through yesterday’s water.
Lay kitchen paper down. Put sheets under the base, behind the machine and around the waste pipe. Paper shows you exactly where the first drop lands.
Switch on from cold and wait. Watch the first 15 minutes of warm-up without touching anything. Note any trickle into the drip tray and where it comes from.
Check the drip tray and waste. Empty the tray, then look at the waste pipe and the standpipe under the counter. Confirm the pipe is seated and falls downhill.
Pull a shot and watch the group. Lock in a loaded portafilter and run it. Look for water escaping round the edge of the handle rather than through the spouts.
Run the steam wand and hot water tap. Ten seconds each, then close them and watch for 60 seconds. A drip that carries on means a worn seat.
Read the paper. Lift the sheets and find the wettest one. Match its position to the sections above and you have your fault.

Fifteen minutes here saves an engineer thirty minutes of guessing, and you can describe the fault properly when you ring.

When to stop and get an engineer

Switch the machine off at the socket and isolate the water if you see any of the following.

Water or steam from a boiler seam or a welded joint
The safety valve lifting
Water anywhere near the electrics or the mains lead
A leak you can’t stop by closing the isolator valve
The machine tripping the RCD or the breaker

How the repair works. Fracino machines are covered back to base. Small and medium machines like the Cherub, Bambino and Little Gem go to the workshop rather than an engineer coming to you.

Collection and return is the customer’s cost. Budget around £95 to collect and £115 to return, so roughly £210 for the round trip. Drop the machine in yourself and there’s no collection fee.

Plan for a few days without the machine. If you can’t lose a bar for a week, a cheap backup single group earns its keep the first time you need it.

How to stop leaks coming back

Treat seals as consumables. Group head seals and shower screens wear out. Change them on a schedule instead of waiting for a leak on a Saturday morning.

Keep the water soft. Scale is what kills valves, seats and boilers. Change the filter or softener cartridge every 2 months — our guide to coffee machine water filters and softeners explains how to work out your water hardness.

Backflush daily. Grounds on a valve seat cause drips that look like a failed part. A proper close-down routine prevents most of them, and our guide to cleaning and descaling a commercial coffee machine sets it out step by step.

Empty the tray before it’s full. Twice a day, every day. It costs nothing and it removes the most common cause of water on the floor.

Straight talk on spares. We don’t list individual seals, gaskets and shower screens on the site. Tell us your model and we’ll sort the right part — guessing from a photo is how people end up with a seal that’s 0.5mm too thin and leaks again in a fortnight.

Five mistakes that turn a drip into a bill

Tightening the handle harder. It wears the group lugs. Change the seal instead.
Trading through a mains leak. A weep at 3 bar becomes a burst at the worst possible moment.
Putting a bucket under it. Buckets hide the fault and get kicked over.
Descaling a machine that’s already leaking. Descaler shifts scale that was plugging a worn seat, and the drip gets worse.
Ignoring the tray. A full drip tray is the most common leak that isn’t a leak.

Time to replace rather than repair?

Sometimes the sums stop working. A tired single group with a scaled boiler, a worn group and a weeping tap is a rolling repair bill.

For a small counter, the tank-fed Fracino Cherub single group starts from £1,240 and needs no plumbing at all. It runs on a standard 13A socket with a 2.85kW element and a 2.3-litre boiler.

For a bar doing real volume, the plumb-in Fracino Bambino 2 Group Automatic starts from £2,380, with a 10-litre boiler and up to 400 cups an hour. Both come with the same back-to-base cover described above.

Frequently asked questions

Why is my coffee machine leaking water from the group head?

A group head that leaks during a shot almost always has a hardened rubber seal. Heat and coffee oils stiffen the gasket until it no longer fills the gap against the portafilter. Grounds on the basket rim and a clogged shower screen cause the same symptom, so clean both before ordering a part.

Is it normal for an espresso machine to drip after a shot?

Yes. A few drips into the drip tray straight after a shot are the three-way valve releasing pressure from the group, which is what leaves you a dry puck. A drip that is still going ten minutes later is not normal and points to a sticking valve or debris on the seat.

Why is water leaking around the edge of the portafilter?

Water escaping round the handle means the seal is not compressing properly. The usual causes are a worn group head seal, coffee grounds on the basket rim, an overfilled basket lifting against the screen, or a shower screen so blocked that water is pushed sideways. Never tighten the handle harder to compensate.

How often should a coffee machine group head seal be replaced?

Every 6 to 12 months on a busy bar, and longer on a quiet counter. Volume, water hardness and cleaning routine all change the interval, so judge by feel rather than the calendar. Press the seal with a fingernail: soft and springy is fine, hard and shiny means it is finished.

Why is there a puddle of water under my coffee machine?

Nine times out of ten it is waste water, not fresh supply. The drip tray drains through a narrow pipe that blocks with coffee grounds and milk, so the tray fills and overflows out of the back. Empty the tray, flush the pipe and check it is still seated in the standpipe.

Can I keep using a coffee machine that is leaking?

A small drip into the drip tray is safe to trade with while you book a repair. Stop immediately if water reaches the electrics, if the safety valve is lifting, if steam escapes from a boiler seam, or if the machine trips the breaker. Switch off at the socket and close the isolator valve.

How much does it cost to repair a leaking commercial coffee machine?

Seals and shower screens are inexpensive consumables. The real cost is getting the machine to the workshop, because Fracino cover is back to base rather than an engineer visit. Budget around £95 for collection and £115 for return, roughly £210 for the round trip, or drop it in yourself and pay nothing for collection.

Does limescale cause coffee machine leaks?

Indirectly, yes. Scale builds on valve seats, taps and boiler fittings until they no longer close cleanly, and the result shows up as a drip. Changing the water filter or softener cartridge every 2 months is the cheapest leak prevention there is, and it protects the boiler at the same time.