How to Prevent Frozen Pipes This Winter

Every winter, frozen pipes cause more emergency call-outs in Peterborough than any other plumbing issue. A frozen pipe is bad enough — a burst pipe is catastrophic, with damage running into thousands of pounds. The good news: most frozen pipes are entirely preventable with a few simple steps before the cold weather hits.

Where pipes are most likely to freeze

Pipes freeze when water inside them cools below 0°C. The most vulnerable locations in a Peterborough home are:

• Loft pipework — particularly the cold water cistern overflow and the rising main where it enters the loft
• External walls — pipes in or against north-facing external walls cool fastest
• Unheated garages, outhouses, and porches
• Under suspended ground floors with poor airflow ventilation
• Outside taps and the pipework feeding them
• Boiler condensate pipes exiting through external walls

Modern pipework in well-insulated cavity walls is much less at risk than older properties with surface-mounted copper on solid walls.

Step 1: Insulate every accessible pipe

The single most effective preventive measure is foam pipe lagging — a slit foam tube that wraps around the pipe and seals back together. It's available at any DIY shop for £2–£5 per metre, comes in standard sizes (15mm and 22mm being most common), and takes minutes to fit.

Priorities, in order:

1. Every pipe in the loft, especially the rising main
2. Pipes in garages, outhouses, and porches
3. The boiler condensate pipe where it exits the property
4. External taps and their feed pipes
5. Pipework on external walls anywhere visible

Don't skip the bends and T-junctions — they freeze first. Use insulation tape to wrap them where moulded foam doesn't fit.

Step 2: Keep the heating on a low setting

If you're away during cold weather, leave the heating on a low constant setting (7–10°C) rather than off completely. The minor cost is much less than the cost of a burst pipe. Modern boilers with frost protection do this automatically, but only if the boiler has power and the controls are set to allow it.

If you have a programmer with a "frost protect" setting, use it. If not, set the room thermostat to its lowest non-zero setting.

Step 3: Know where your stopcock is

Find the internal stopcock now, before you need it. In most Peterborough homes it's:

• Under the kitchen sink, on the rising main
• In a utility room or under-stairs cupboard
• In the garage or boiler cupboard in newer builds

Test it by turning the tap clockwise — it should close after a few full turns. If it's stiff or won't move, exercise it gently or have it replaced. A seized stopcock during a burst pipe is a very expensive problem to discover too late.

Step 4: Drain external taps for winter

Outside taps are the most common cause of winter pipe failures. Before the first frost:

1. Find the internal isolation valve for your outside tap (usually in the wall just inside the property, sometimes under the kitchen sink)
2. Close the internal valve
3. Open the outside tap fully and leave it open all winter
4. Drain any remaining water by opening the bleed nut on the isolation valve if fitted

If your outside tap has no internal isolation valve, fitting one is worth the £15–£30 part cost. A 20-minute job saves a winter call-out and the associated water damage.

Step 5: Open cupboard doors on very cold nights

Pipes under kitchen and bathroom sinks against external walls benefit from warmer room air reaching them. Opening the cupboard doors overnight on the coldest nights lets warm air circulate around the pipework.

Step 6: Drip the taps on extreme cold

If temperatures are forecast below -5°C for sustained periods (rare in Peterborough but does happen), allow a small trickle from cold taps on exterior walls. Moving water is far harder to freeze than still water. Use the cold tap nearest the most vulnerable pipework.

If a pipe does freeze

You'll usually notice frozen pipes when a tap or appliance has no water but the rest of the property is fine. To thaw safely:

• Turn off the stopcock first. If the pipe has burst, this prevents water flooding once it thaws.
• Locate the frozen section. Usually visible — frost on the outside or the pipe is unusually cold to touch.
• Apply gentle heat. Warm towels wrapped around the pipe, a hairdryer on a low setting, or hot water bottles. Start from the tap end and work back towards the stopcock.
• Never use a blowtorch, naked flame, or boiling water. All three can cause the pipe to split.
• Open the affected tap so water can flow as the ice melts.

If the pipe has already burst, see our burst pipe emergency guide for the next steps. Our emergency plumbers attend frozen and burst pipes across all PE postcodes year-round.

Going away for the winter

If leaving the property empty for more than a week in cold weather:

• Turn off the stopcock and drain the system (open all taps and flush all toilets)
• Turn off the boiler unless leaving it on for frost protection
• Ask a neighbour to check the property every few days
• Confirm your home insurance covers extended unoccupied periods — many policies require visits every 30 days or less

A small amount of preparation in October or November typically prevents the most expensive plumbing failure a homeowner can experience.