How to Winterise an Empty or Holiday Property in Chelsea

Updated July 2026 · Emergency Plumber Chelsea

Start by deciding between two strategies: keep low heat running, or drain the system down. For a home empty a few weeks over winter, or one you visit occasionally, leaving the heating on a low frost-protection setting (around 12 to 15 degrees) is usually simplest and keeps pipework above freezing. For a property standing empty for months with nobody checking it, draining the water system removes the risk entirely, because a pipe with no water in it cannot burst. If you cannot guarantee a reliable check during cold snaps, draining down is the safer choice.

If you choose to keep the heating on, set the thermostat to a constant low temperature rather than turning it off. Many boilers and thermostats have a frost-protection or holiday mode that fires the heating only when the temperature drops near freezing. Leave interior doors open so warmth reaches colder rooms, and open the loft hatch a little so heat from the house below rises into the roof space, where cold-water tanks and pipes often sit unprotected. Keep the boiler serviced before winter so it does not fail while you are away.

Insulate every pipe you can reach, especially those in unheated areas. Foam lagging on pipes in the loft, under floors, in the garage, in outbuildings and against external walls is cheap and effective. Pay particular attention to the boiler condensate pipe if it runs outside, because a frozen condensate pipe is one of the most common cold-snap boiler lockouts in Chelsea. Insulate cold-water tanks in the loft and check that existing lagging has not slipped or perished. Do not insulate underneath a loft tank, so a little warmth from below can still reach it.

Locate the internal stopcock and test that it turns before you need it in a hurry. In many Chelsea homes and mansion flats the stopcock is under the kitchen sink, in a utility cupboard, in a downstairs cloakroom or near the front door. Turn it clockwise to close and check it moves freely, then reopen it. A seized stopcock is useless in an emergency, so a stiff or leaking valve is worth replacing before you leave the property empty. Note the location and write it down for anyone checking the home.

If you are draining the system, turn off the water at the stopcock, then open every tap, upstairs and downstairs, hot and cold, to let the pipes empty. Flush the toilets to empty the cisterns. Drain the cold-water storage tank and, where fitted, the hot-water cylinder. On a heating system, only drain it if you know what you are doing or have a plumber do it, because refilling and rebleeding a central heating system afterwards takes care. Once drained, a little non-toxic antifreeze in toilet pans and traps stops the small amount of remaining water freezing and cracking the ceramic.

For a partial approach, consider isolating and draining only the most vulnerable sections while leaving the core system live and heated. For example, you might isolate and drain an outside tap, a garden supply, or plumbing in an unheated outbuilding, while keeping the main house on low heat. Every external tap should have its internal isolation valve closed and the outside tap opened to drain, so trapped water cannot freeze and split the pipe or the tap body. This middle path suits a home that is checked regularly but has awkward frost-prone runs.

Protect the drainage and waste side too. Standing water in traps can freeze in a very cold, unheated home, and an unused property can develop drain smells as traps dry out over weeks of no use. If you are leaving the home heated, this is rarely an issue. If you are draining down for a long empty period, adding a little antifreeze to sink, bath, shower and toilet traps keeps them protected and sealed. Make sure gutters and outside gullies are clear of leaves before winter, because a blockage that overflows and freezes can force water back towards the building. In older Chelsea terraces and basement flats, where drainage runs are long and sometimes shared, a small autumn clear-out is worth doing before you lock up.

Do not overlook the boiler and heating controls themselves. Leave the boiler switched on if you are keeping frost protection running, because the boiler needs power to fire during a cold snap. Set the programmer so heating comes on for a period each day rather than never, which keeps water moving through the system. If you are draining everything down and switching the boiler off, turn off the gas supply at the meter and, where relevant, the electric supply to the boiler, and note that a Gas Safe registered engineer should recommission a gas boiler that has been fully shut down for a long spell.

Arrange for someone to check the property during winter, and make the checks meaningful. A neighbour, concierge, managing agent or trusted contact should look in at least weekly, and more often during a hard freeze, to confirm the heating is running, there are no leaks or damp patches, and the boiler has not locked out. Give them the stopcock location, your plumber's number and clear instructions to turn the water off and call for help if they find a leak. Ask them to open a tap briefly to confirm water is flowing and, on a heated home, to feel a radiator to check the system is warm. In a mansion block, tell the concierge or managing agent that the flat is empty, so they can act quickly if a leak is reported from a flat below, where escaping water often shows up first.

Think about insurance and access before you leave. Many home insurance policies have specific conditions for properties left unoccupied over winter, often requiring the heating to be kept on at a minimum temperature or the water to be drained down, and failing to meet those conditions can void a claim. Check your policy wording, keep a record of what you did to winterise, and make sure keys and access details are available to whoever will respond in an emergency. A short written note left in the home helps any plumber who attends work quickly.

If the worst happens while the property is empty, fast isolation limits the damage. A burst pipe can release a large volume of water over hours or days in an unattended home, so the priority is always to shut the stopcock and stop the flow before anything else. Once the water is off, open the cold taps to relieve pressure, protect what you can, and get a permanent repair arranged. Emergency Plumber Chelsea attends burst pipes, frozen pipes and boiler failures across SW3, SW10 and nearby postcodes at any hour. Call 020 3002 6667 and describe the situation and the access arrangements.

In short: pick heat-on-low for a short empty spell with regular checks, or a full drain-down for a long unattended winter. Whichever route you take, insulate exposed pipes, know and test your stopcock, protect the condensate pipe and traps, and line up someone to look in. A couple of hours of preparation before you lock up is far cheaper than returning to a flooded Chelsea home in January.

Quick tips

• Short empty spell with checks: leave heating on frost protection at 12 to 15 degrees. Long unattended winter: drain the system fully.
• Test the stopcock turns freely before you leave, and write down its location for whoever checks the home.
• Insulate loft, garage and external pipes, and leave the loft hatch slightly open so house warmth reaches tanks and pipework.
• Isolate and drain outside taps and any unheated outbuilding plumbing even if the main house stays heated.
• Check your insurance policy's unoccupied-property conditions on heating or draining down, so a winter leak claim is not refused.

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