Before you leave in autumn, preparing your Mallorca second home for winter is worth an afternoon. The real threat is humidity: in January the average temperature in Palma is 9.5 °C, yet relative humidity sits around 79 % (AEMET). Keep indoor humidity between 40 and 60 %, set the air conditioning or heat pump to an away setting, unplug standby loads (about 300 kWh a year, IDAE) and secure the water and the solar system. This checklist takes you through it step by step.
By the technical team at Greentech Balear · Published 7 October 2026 · Updated 7 October 2026
What is the real risk in a mild winter?
Damp is the biggest risk to an empty Mallorca second home. On the coast the temperature rarely drops below freezing. In January, the coldest month, AEMET records a mean minimum of 3.8 °C and an average relative humidity of 79 % at Palma airport. A closed house slowly cools, moist air condenses on cold walls, and mould appears in wardrobes, bathrooms and unventilated bedrooms.
Aim for indoor humidity between 40 and 60 %. Spain’s Regulation on Thermal Installations in Buildings (RITE, IT 1.1.4.1.2) sets 40 to 50 % as the winter comfort range and advises staying below 65 % so that condensation does not form. Provide controlled ventilation or a dehumidifier with a humidistat. For damp rooms that need a permanent fix, we go into detail in our guide to ventilation for second homes with a musty indoor climate. If you would rather hand the checks over before you leave, our maintenance and property-care service takes care of the regular visits.
How should you set each system before you leave?
Set each system deliberately to a winter mode instead of simply switching everything off. A completely cold, unventilated flat draws more moisture than one kept slightly warm. The table below sums up what we set before every winter break.
| System | Setting before you leave | Why |
|---|---|---|
| Air conditioning / heat pump | Away or frost-protection mode, about 10–12 °C; clean the filters | Keeps the home dry and prevents deep cooling without heating throughout |
| Water | Close the main stopcock, drain pipes and the boiler or set frost protection | Prevents leaks and legionella in standing hot water |
| Photovoltaics and battery | Leave the system connected, enable remote monitoring, battery on standby | The system keeps producing and you see faults through the app |
| Standby loads | Switch off router, TV and chargers via a switchable power strip | Avoids around 300 kWh of needless yearly consumption (IDAE) |
| Fridge | Empty it, defrost it, leave the door open | Prevents mould and odours inside |
Choose the away mode if you visit every few weeks or let the property. Choose frost protection with a dehumidifier if the home stays empty all winter.
What steps do we follow to winterise a second home?
This is how we prepare a second home before the winter break:
- Inspection and survey of the building systems (half a day), with a photo record.
- Service the air conditioning or heat pump, clean the filters and set the away mode.
- Secure the water circuit: main stopcock, boiler and, where needed, frost protection on outdoor pipes.
- Check the solar system and battery and set up remote monitoring so faults stay visible.
- Build moisture protection: ventilation or a dehumidifier with a humidistat set to 55 %.
- Agree a winter-care plan: scheduled visits, a named contact and an emergency number.
Allow one to two working days to prepare an average home fully. The follow-up visits take around an hour each.
What we see again and again in Mallorca second homes
Demand for property care is high among our German-speaking owners. According to Greentech Balear’s Search Console data (June to September 2026), searches such as “Hausbetreuung Mallorca” and “Finca Betreuung Mallorca” are among the queries that bring German-speaking owners to us, and we appear at an average position of 6.5 for “Hausbetreuung Mallorca”. It matches what we see on site: most damage happens in the months when no one is in the house.
Two patterns stand out. First, damp damage in closed houses with no ventilation, usually behind wardrobes on outside walls. Second, needless electricity use from devices left on standby: suppose loads totalling 150 watts stay connected for four winter months; that adds up to about 432 kWh — an example that shows why a switchable power strip pays off. A short preparation before you leave avoids both.
Frequently asked questions
Should I switch the heating off completely over winter?
No. A completely cold house absorbs more moisture. Set the air conditioning or heat pump to a frost-protection or away value of about 10 to 12 °C. That keeps the home dry without heating it through.
How do I keep humidity in check when no one is there?
A dehumidifier with a humidistat set to 55 % holds indoor humidity in the healthy 40 to 60 % range (RITE). Alternatively, controlled home ventilation provides constant air exchange even with the windows closed.
What happens to my solar system in winter?
The system stays connected and keeps producing, even with the sun lower in the sky. Enable remote monitoring and you will see output and faults through the app. A battery remains on standby and covers the base load when needed.
Do I really have to turn off the water?
Yes, it is the cheapest insurance against water damage. Close the main stopcock and drain the boiler or set it to frost protection. Standing hot water also encourages legionella.
Is professional winter care worth it?
If your home sits empty for months, yes. Regular visits catch leaks, damp or faults early, before they become expensive damage. That is far cheaper than a spring refurbishment.
Sources
- AEMET — Normal climate values, Palma de Mallorca Airport (1981–2010): January mean 9.5 °C, mean minimum 3.8 °C, humidity 79 %.
- RITE — Regulation on Thermal Installations in Buildings, IT 1.1.4.1.2: indoor humidity 40–60 %, below 65 % against condensation.
- IDAE — Institute for Energy Diversification and Saving: household standby consumption around 300 kWh/year (about 7–11 % of electricity use).
Get your Mallorca second home ready for winter in good time. Call us on +34 644 450 672, write to info@greentechbalear.com, or take a look at our maintenance and property-care service in Mallorca.
*By the technical team at Greentech Balear – energy solutions and building technology in Mallorca: photovoltaics, air conditioning, heat pumps, heating and maintenance.*