Plumbing

Frozen pipes in second homes in Andorra: how to prevent them and what to do if they burst

Where a plumbing system freezes first, what to do before closing the house for a few weeks, and how to act if no water comes out or a pipe has already burst.

1 September 2026 · 5 min read · Andorra Servei

A second home in Andorra that stays shut between visits, with the heating off and the water on, is the classic case of a pipe burst by frost. Water expands as it freezes and splits the pipe or the meter at its weakest point. The worst part is that you do not see it until it thaws: by the time you arrive, water has been pouring out for hours. Preventing it is simple and costs far less than the repair.

Where it freezes first

Not every part of the system carries the same risk. From the call-outs we attend every winter, the weak points are almost always the same:

• Pipe runs through outside walls, garages or storerooms with no heating.
• Outdoor taps and terrace or garden irrigation that were not drained in autumn.
• The water meter and stopcock when they sit in a cabinet on the façade or on an open landing.
• Water heaters and cylinders in lofts or under the roof.
• Uninsulated copper or multilayer pipes in north-facing walls.

Flats in buildings with central heating are at lower risk. Where we see it most is in chalets, renovated village houses and apartments at altitude in parishes such as Canillo or Encamp, especially when several nights in a row drop well below zero.

Before you leave the house for a few weeks

If the heating stays on

The easiest option is to leave it on frost protection mode or at a low, steady temperature. Many thermostats and boilers have this setting. You do not need to heat the house, only to make sure no room and no stretch of pipe drops below zero. Check it before you go and, if possible, fit a connected thermostat that alerts your phone if the temperature falls too low or the boiler stops.

If the heating is switched off

1. Close the main stopcock.
2. Open every tap, hot and cold, starting with the highest ones, and leave them open until nothing more comes out.
3. Empty the toilet cisterns by flushing with the stopcock closed.
4. Drain the water heater or cylinder if it is in a cold area. Switch it off at the mains first: an empty heater left powered will burn out.
5. Pour a little sanitary antifreeze into the traps if the house will get very cold; the water in the traps freezes too.

The heating circuit

If you have radiators or underfloor heating and the house may go many days without heat, the circuit can freeze as well. Heat pump and solar thermal systems often run on a glycol mixture that protects against frost. If you are not sure whether yours does, ask at the autumn service, before the first frosts: the concentration takes a moment to measure.

Upgrades that are worth it

• Insulating exposed pipe runs with foam pipe lagging. It is inexpensive and takes a few hours.
• Trace heating cable on outdoor or garage runs that cannot be insulated enough: it only heats when needed, controlled by a thermostat.
• A separate isolation valve for outdoor points, so you can drain irrigation and terrace taps without cutting water to the house.
• An automatic shut-off valve with a leak sensor: it closes the supply if it detects water. Especially useful in second homes.

If you arrive and no water comes out

The pipe may be frozen but not yet split. Do this:

1. Close the stopcock before anything else. If there is a crack, water will start leaking as it thaws.
2. Open the affected tap so the water has somewhere to go as it thaws.
3. Warm the room and, if you can find the frozen section, apply gentle heat with a hairdryer or warm cloths, starting from the tap end.
4. Never use a flame or blowtorch: you can burn the insulation, damage plastic joints or start a fire.
5. Once water flows again, open the stopcock slowly and keep an eye on walls, ceilings and cupboards for a while.

If the pipe has already burst

Close the main stopcock and, if water has reached sockets or the consumer unit, switch off the main switch. Take photos before cleaning up: your insurer will ask for them. If it is a flat, warn the neighbours below. The exact point then has to be located, which does not always match where the stain appears, and the damaged section replaced. With pipes buried in walls, good leak detection equipment makes the difference between opening a small patch and opening half the bathroom.

When we repair a frozen section, we also look at why it froze: unless the insulation or the routing is corrected, it will happen again next winter.

When you do not need to do anything

If the home is inside a heated building and indoor temperatures stay reasonable, the risk is very low. Nor do you need to drain the system for a weekend away with the heating running on frost protection.

If you would like us to check your second home before winter or you need a repair, see our plumbing service in Andorra or, for questions about the heating circuit, our heating and air conditioning service. To book a visit, get in touch through the contact page.