Frozen Pipes and a Frozen Condensate Pipe: What to Do in a Fife Winter

It's the first hard frost of the winter. You turn on the kitchen tap and nothing comes out. Or the heating went off overnight, the boiler is showing a fault code, and something behind it is gurgling. In a Fife cold snap both usually come down to ice, either in a water pipe or in the small plastic pipe that drains your boiler. Here's how to tell which, how to thaw each one safely, what to do if a pipe bursts, and who is responsible for which pipe in Scotland.

Is it a frozen pipe, or something else?

Two kinds of pipe freeze, and they give you different symptoms:

• One tap gives nothing, or a trickle, and the others run. A water pipe has probably frozen on the way to that tap. Look first at pipes in the loft, in a garage, under the floor, along an outside wall or feeding an outside tap.
• No water at any tap. It could be a frozen pipe near where the supply comes in, or a problem in the street. Ask a neighbour whether they have water, and check the supply map on Scottish Water's website.
• The boiler has stopped, with a fault code and a gurgling noise. On a condensing boiler that's the classic sign of a frozen condensate pipe.
• Water coming through a ceiling, or a hiss behind a wall. That's a burst. Go straight to the burst pipe steps below.

Often the trouble starts when it thaws. As Scottish Water explains, water in a pipe freezes and expands, then contracts as the temperature rises, and that can crack or burst the pipe. Scottish Water recorded 3,100 bursts across Scotland's water network in the winter of 2023 to 2024, and more than 30% of them were on customers' properties.

A frozen condensate pipe: the boiler fault you can often fix yourself

If your gas boiler was fitted in the last 15 years or so, it's most likely a condensing boiler. It squeezes extra heat out of the flue gases, which turns water vapour back into water, around 2 litres an hour on average according to Vaillant. That water drains away through a plastic pipe, usually white or grey, which often runs through the wall and down to a drain outside.

When the outside part freezes, the water has nowhere to go and the boiler shuts down. Baxi describes the shutdown as a failsafe that stops water backing up into the boiler and damaging the electrics. You lose heating and hot water together. You may hear gurgling or bubbling, and in most cases the boiler shows a fault code. Vaillant boilers show F28 or F29, most Baxi boilers show E133 or E28, and Worcester Bosch boilers may show EA. Other makes use their own codes, so check your manual.

If you still have hot water but no heating, or the other way round, it isn't the condensate pipe. Our guides to hot water but no heating and heating working but no hot water cover those faults.

How to thaw a frozen condensate pipe

The boiler makers give much the same advice, and so does the industry guidance from HHIC, the heating industry body, published by the Gas Safe Register:

• Find where it's frozen. Follow the pipe from the bottom of the boiler to where it leaves the wall. It usually freezes at the most exposed point outside: the open end, a bend, or a dip where water sits.
• Only carry on if you can reach it from the ground. HHIC says not to use water if the pipe isn't easy to reach from ground level, and to get a heating engineer instead. Don't go up a ladder on ice for it.
• Use warm water, never boiling. Pour it along the frozen section from a watering can or jug, or hold a hot water bottle or a microwaveable heat pack against the pipe. Vaillant warns that boiling water from the kettle can crack the pipe, and then you have a repair to pay for and the boiler still off. Watch your footing too, because the water you pour can freeze on the path.
• Reset the boiler. Once the ice clears, follow the reset steps in your boiler's manual. Usually that's a reset button on the front. On some boilers you switch the power off and back on.

If it still won't restart once the pipe is clear, Baxi's advice is to call a Gas Safe engineer. Do the same if it keeps locking out, rather than resetting it again and again. That's a boiler repair job.

How to unfreeze pipes safely

A frozen water pipe is a different job, because it's part of your supply and it can split. Scottish Water's advice is:

• Turn off the stop valve straight away. It normally closes clockwise.
• Open all the cold taps to drain the system. Don't turn on the hot taps. If you have a hot water cylinder, it may collapse if the pipes leading to it are frozen.
• Don't try to thaw the pipe by switching on the immersion heater or the boiler.
• Check the frozen section for leaking joints or splits.
• If it's safe to reach, warm the frozen section gently with a heated cloth wrapped round the pipe. Never use a naked flame.
• Call a plumber if you're in any doubt.

Go slowly. If the pipe split when it froze, you won't know until the ice melts and water starts to come out. That's why the stop valve goes off before you warm anything.

A stiff or broken stopcock is a common job for us. One customer's Checkatrade review from December 2022 describes a visit where our plumber “replaced the stopcock and checked the pipes, water tank and put the insulation back on”.

Burst pipe? What to do straight away

Move fast. These are Scottish Water's steps for a burst, in order:

• Turn off the stop valve. It normally closes clockwise.
• Switch off the boiler and the immersion heater, and let any solid fuel fire die down.
• Open all the taps, hot and cold, to drain the pipes and limit the damage. With a burst, the hot taps go on too.
• Turn the electricity off at the mains if water could reach any wiring or fittings. If you're unsure, call an electrician rather than take the risk.
• In a flat, terrace or semi, check on the neighbours. You may share a supply, and turning off your water can cut off theirs.
• Get a plumber in. A repair clamp from a DIY shop can hold a split for now, but Scottish Water says it should be replaced with a permanent repair as soon as possible, and recommends a licensed plumber for that.

Once it's repaired, refill the hot water system before you relight the boiler or switch the immersion heater back on. Scottish Water singles that one out.

Pipes outside the house burst too. One customer's Checkatrade review from February 2021 starts: “Burst outside pipe threatening to create an ice rink on pavement and road.” In their words, Liam “stopped the flooding and repaired the pipe”.

If a pipe has burst in Kirkcaldy or anywhere in Fife, call our emergency plumbing line. If you can't find your stopcock, we'll help you find it over the phone. Then we find the burst, repair it and check the rest of the run so it doesn't go again.

Who is responsible for which pipe in Scotland?

When a pipe bursts outside, the next question is who pays. Scottish Water sets it out like this:

• The water main under the street is Scottish Water's.
• The communication pipe, which runs from the main to your property boundary, is Scottish Water's too. So is the stopcock where it meets your boundary, and the water meter if you have one.
• The supply pipe, from your boundary to the stop valve inside your home, is yours to maintain. If it's shared, which is common with flats and older or terraced houses, you and your neighbours are jointly responsible.
• The stop valve inside the house, and all the plumbing indoors, are yours.

Watch the two names. In Scottish Water's terms the stopcock is their valve at the boundary and the stop valve is yours, inside. Most people call the one inside the stopcock, so say which you mean if you ring them.

Scottish Water is not responsible for burst or frozen pipes in your home or within your property boundary. A burst on the public network, in the road or the pavement, is theirs to fix: report it on 0800 0778 778, which they answer 24 hours a day, or through the report a problem form on their website. A burst on your side of the boundary is yours to get repaired, although Scottish Water says it can sometimes help.

Not sure which side of the line the leak is on? A plumber can trace it before anyone starts digging. Underground supply pipe leaks and old lead pipes are part of our water mains work.

How to stop pipes freezing

Scottish Water's winter advice is to heat, insulate and protect:

• Insulate exposed pipes and tanks. Scottish Water calls it one of the simplest and cheapest things you can do. Leave no gaps at bends, valves or fittings. Lag the cold water tank in the loft round the top and sides, but don't lay loft insulation directly under it, because heat from the rooms below helps keep it from freezing.
• Leave the boiler switched on. Most modern boilers have frost protection built in, which fires the heating if the water in the system gets too cold, but only if the boiler has power. If yours doesn't have it and you're going away in cold weather, Scottish Water suggests setting the room thermostat to 10°C and the programmer to on or 24 hours.
• Let the heat reach the pipes. Leave internal doors open so warmth gets to every room with pipes in it. Thermostatic radiator valves on their frost setting protect rooms you're not using for very little energy.
• Don't leave taps running. Scottish Water says it wastes water and doesn't guarantee protection against bursts. Isolate and drain outside taps you won't use over the winter, and get drips fixed, because dripping water makes freezing more likely.
• Leaving a house empty? Ask someone to check on it. If it'll be empty all winter, turn off the water and drain the system. A plumber can advise you on that. Leave the boiler on for frost protection, and check your buildings and contents insurance covers you.

Stopping the condensate pipe freezing again

Wrap the outside section in foam pipe insulation from any DIY shop. Scottish Water, Vaillant and Baxi all recommend it. Vaillant adds that the pipe is more likely to freeze when the boiler hasn't been running in a cold spell, say while you're on holiday, so keep it on a timer.

If yours freezes every winter, it may not meet current guidance. HHIC says the condensate from a new or replacement boiler should drain to a point inside the house, ideally the soil stack. Where a pipe has to run outside, it should be:

• At least 30mm inside diameter (typically 32mm pipe), wider than the pipe used indoors.
• Insulated with at least 13mm of waterproof, UV-resistant insulation, sealed at every joint.
• No more than 3 metres long outside, on the most direct, most vertical route, with no flat sections where water can sit.
• Cut at 45 degrees at the end, finishing below the drain grid but above the water, with a leaf guard over the drain.

HHIC says even that may not be enough in extreme, prolonged cold. The other fixes are a trace heater, an electric heating cable run along the pipe, or moving the pipe so it runs inside. Baxi suggests asking a Gas Safe registered installer about both.

Under HHIC's guidance, an engineer servicing or repairing a boiler should check how the condensate pipe is run and whether it can be upgraded, so ask at your next boiler service. On a Worcester Bosch combi we fitted in Livingston, the condensate pipe leaves the wall and drops straight into a trench to the drain instead of running down the brickwork.

When to stop and call someone

Most of the above is safe to do yourself. Call a plumber or heating engineer when:

• A pipe has burst. Water off at the stop valve, power off at the mains if it's near the electrics, then ring.
• You can't find the stop valve, or it won't turn.
• The frozen pipe is out of safe reach, like a condensate pipe high up a wall or pipework in a loft you can't get into safely.
• The boiler won't restart after the condensate pipe has thawed, or keeps locking out.
• Someone vulnerable is at home with no heating. With young children, an elderly relative or someone unwell in the house, treat it as urgent and say so when you ring.

Frozen and burst pipes in Kirkcaldy and across Fife

We're a Gas Safe registered plumbing and heating team based in Kirkcaldy, covering Glenrothes, Leven, Dunfermline, Cowdenbeath and the rest of Fife, and through to Edinburgh and the Lothians. We tell you the price before we start. There's more on our emergency plumbing page.