When you go on holiday, leave your heat pump powered on and use its holiday or away mode, or lower the room temperature, rather than switching it off. Keeping the power on lets the unit run its built-in frost protection and hot water disinfection cycles, which protect the pipework, the outdoor unit and the water in your cylinder while nobody is home.
The right setting depends on the season, how long you are away and whether the property is a main home or a second home.
What Is Holiday Mode on a Heat Pump?
Holiday mode is a controller function that runs your heat pump at reduced settings between two dates, then returns it to your normal schedule automatically. Each manufacturer names and configures it differently, and what it does to heating and hot water varies, so check the manual for your controller and software version.
| Brand and control | Name of the function | What it does to heating | What it does to hot water |
|---|---|---|---|
| Vaillant (myVAILLANT app) | Absence mode | Switches to the set-back temperature | Hot water continues, which Vaillant says protects the cylinder from legionella |
| Mitsubishi Ecodan (FTC main controller, MELCloud) | Holiday mode | Runs at lower flow or room temperatures to cut power use; start and end dates can be set | Hot water can also run at a reduced temperature |
| Daikin Altherma 3 M (user interface) | Holiday | Space heating is turned off between the “From” and “Till” dates | Tank heating is turned off, but disinfection, room frost protection and pipe freeze prevention stay active |
| Samsung EHS (MWR-WW10N wired controller) | Outing mode | Heating runs at a lower target temperature set by the installer | Hot water target is also reduced; disinfection needs a booster heater fitted |
Older controllers and newer software may label these differently. If you cannot find the function, your installer can show you where it is.
Should I Switch My Heat Pump Off at the Isolator When I Go Away?
No, you should not switch your heat pump off at the isolator or the fused spur when you go away. With the power off, the unit cannot protect itself or your pipes from frost, and it cannot run its hot water disinfection cycle.
The outdoor unit and the pipes running to it hold water. In cold weather the heat pump watches the water temperature and runs the circulating pump, or starts heating, if it gets close to freezing. Daikin’s documentation, for example, says room frost protection and water pipe freeze prevention stay active even when heating is switched off at the controller. None of that works without electricity.
Some systems have anti-freeze valves on the outdoor pipework. These open when the water drops below about 3°C and let system water drain out to stop it freezing. If the unit has no power and cannot circulate warm water, those valves may discharge, and the system then needs refilling and repressurising before it works again.
Summer matters too. Samsung’s controller manual states that during longer periods of standstill, such as summer with a heating-only system, it is very important not to switch off the power supply to the unit. Keeping the power on lets the pump exercise itself so it does not seize.
Turning the mains water off at the stopcock is a different matter. Your heat pump’s heating circuit is sealed, so closing the stopcock does not stop the heat pump running. The Association of British Insurers suggests turning off the water or leaving heating on a timer to reduce the risk of burst pipes. Doing both, with the heat pump left powered, covers most risks.
What Temperature Should I Leave My Heat Pump on in Winter?
For a winter trip, we suggest leaving the heating at around 12–15°C rather than letting the house go cold. That keeps pipes safe, limits condensation and damp, and means the heat pump does not have to work hard for days to recover when you return.
Heat pumps use low flow temperatures and are slower than a boiler to lift a cold house back up. A deep set-back of 5°C or 6°C can save a little energy while you are away, then cost much of it back in a long recovery run, sometimes with the immersion or backup heater cutting in. A moderate set-back avoids that.
| Trip | Winter (October to March) | Summer (April to September) |
|---|---|---|
| 1–3 nights | Leave the normal schedule, or drop the room target by 2–3°C | Heating is usually off already; leave hot water on its normal schedule |
| 4–14 nights | Holiday mode or a room target of about 15°C | Holiday or away mode with heating off and hot water reduced, keeping the disinfection cycle |
| 2 weeks or more | Holiday mode or a room target of about 12–15°C | Holiday or away mode, power left on; ask your installer about the disinfection schedule |
| Empty for months | Frost protection plus a low room target; get advice on draining if the property will stay unheated | Power on, heating off, disinfection active; arrange regular checks |
These figures are our general guidance, not a manufacturer requirement. Damp-prone or poorly ventilated homes may need the higher end of the range.
When Should the Heating Come Back On Before I Return?
Set holiday mode to end, or the room target to rise, about 24 hours before you get home in winter. That gives a heat pump running at low flow temperatures time to bring the fabric of the house back up gradually. On most controllers you can set the end date to the day before your return rather than the day itself.
What Should I Do With My Heat Pump for a Summer Holiday?
For a summer holiday, you can usually leave the heating off and just reduce or pause hot water, keeping the power on. Most heat pumps are in summer or hot-water-only mode by late spring anyway.
The main summer risk is water sitting still in a cylinder that has cooled for weeks. We would not turn hot water off completely for a long summer trip unless the disinfection cycle stays enabled or you run a high-temperature cycle before using the hot taps again.
How Should I Handle Hot Water and Legionella While I Am Away?
Keep your heat pump’s disinfection cycle switched on while you are away, and run a disinfection cycle or flush the outlets when you return if the cylinder has been off or at a low temperature. This is often called the legionella cycle or anti-legionella function.
Heat pumps usually store hot water below 60°C day to day because lower temperatures are more efficient. That is under the 60°C the Health and Safety Executive recommends for stored hot water in its legionella guidance. To cover the gap, most systems heat the cylinder to a higher temperature on a schedule, often weekly, using the heat pump and the immersion heater together.
- Vaillant: absence mode keeps hot water running, which Vaillant describes as protecting the system and cylinder from legionella.
- Daikin: holiday mode turns tank heating off, but the disinfection function remains active.
- Samsung: the disinfection function only works when a booster heater is connected, and you can set its day, time, temperature and duration.
- Mitsubishi Ecodan: the controller has a separate legionella prevention setting; ask your installer how it behaves while holiday mode is running on your system.
The HSE’s guidance for landlords advises that in unoccupied homes, hot and cold outlets should be used at least once a week to keep water moving, and that longer empty periods need a flushing regime or draining. The risk in a typical home with daily use is low. The risk rises when a house sits empty with water standing in the pipes, which is exactly what a holiday does.
What Should I Do With the Hot Water on My First Day Back?
On your first day back, run a disinfection cycle if one did not run while you were away, then run each hot and cold tap and shower for a couple of minutes. Let showers run for a while before stepping in, so you are not breathing in spray from water that has stood in the pipes.
Does a Weekend Away Need Different Settings From a Month Away?
Yes, a weekend away needs very little change, while a month away is worth setting up properly with holiday mode and a return date. The longer the absence, the more there is to gain from lower temperatures and the more the hot water and frost risks grow.
| Setting | Weekend or short break | Long absence (2 weeks or more) |
|---|---|---|
| Power at isolator | On | On |
| Heating | Normal schedule or 2–3°C lower | Holiday mode, or around 12–15°C in winter |
| Hot water | Normal schedule | Reduced or off, with disinfection kept on |
| Return timing | No change needed | End holiday mode about 24 hours early in winter |
| Stopcock | Optional | Consider closing it |
| Someone checking the house | Not usually needed | Useful, and may be an insurance condition |
For a weekend, the saving from changing settings is small, and leaving the schedule alone is often the simplest option.
How Should I Set Up a Heat Pump in a Second Home?
A heat pump in a second home should stay powered all year, with frost protection enabled, a low background room temperature in winter, a working disinfection schedule and a Wi-Fi connection so you can see it from your phone. That combination does most of the work that a visit would otherwise do.
Points we would add for a second home or holiday let:
- Ask your installer to confirm frost protection and pipe freeze prevention are enabled in the installer menu, and what minimum temperatures they are set to.
- Set a background heating temperature for winter rather than relying on frost protection alone, which only prevents freezing and does nothing about damp.
- Keep the disinfection cycle scheduled, and run the taps at the start of each stay.
- Check the Wi-Fi router is on a supply that stays on, so remote control still works when you are not there.
- If the home will be unheated for a long period, ask your installer about draining down or using glycol protection. Do not drain a heat pump system yourself.
What Does My Home Insurance Expect If I Leave the Heating Low?
Many home insurance policies limit cover if the home is left unoccupied beyond a set period, often 30 days or more, and some require heating to be kept on or the water drained in winter. The exact rules vary by insurer and policy, so read your own policy wording before you go.
The Association of British Insurers advises checking your policy for restrictions or specific requirements if your home will be empty for more than a specified period. It also suggests setting heating on a timer or turning off the water at the stopcock when going away. According to the ABI, insurers settled roughly 8,000 claims for weather-related pipe damage in 2024, at an average cost of almost £33,000.
Things to look for in the policy:
- How many consecutive days count as unoccupied.
- Whether escape of water or frost damage is excluded or reduced after that point.
- Any minimum heating temperature or requirement to drain the water system.
- Whether someone needs to check the property at set intervals.
If the wording on heating is unclear, ask the insurer whether holiday mode at a moderate room temperature meets it, and note the settings you used before you left.
Can I Control My Heat Pump Remotely While I Am Away?
Yes, most current heat pumps can be controlled from a phone app when the indoor controller is connected to your home Wi-Fi. You can check temperatures, change holiday dates, and bring the heating back on early if your plans change.
| Brand | App | Useful away features |
|---|---|---|
| Vaillant | myVAILLANT | Absence mode from the system overview screen |
| Mitsubishi Ecodan | MELCloud | Starts the Ecodan’s holiday mode remotely with start and end dates; frost (fabric) protection with a minimum room temperature |
| Daikin | Onecta | Remote control of heating and hot water settings |
| Samsung | SmartThings (with EHS Wi-Fi kit) | Remote control of heating and hot water |
Most apps need the unit to stay online to work. Mitsubishi notes that MELCloud’s holiday and frost protection functions rely on the system staying connected. Test the app from outside your home network before you leave, not on the first day of the holiday.
What Should I Check When I Get Home?
When you get home, check the controller shows no faults, the system pressure is in range, holiday mode has ended and the hot water has been through a disinfection cycle. Most of this takes a few minutes.
- Look at the controller or app for fault codes or warnings logged while you were away.
- Check the pressure gauge on the indoor unit against the figure your installer gave you at handover. A drop can mean an anti-freeze valve has opened or there is a leak.
- Walk round the outdoor unit. Clear leaves, snow or anything blown against it, and check the area underneath is draining.
- Confirm holiday or away mode has ended and your normal schedule has resumed.
- Run a disinfection cycle if needed, then flush hot and cold taps and showers.
- Open the stopcock if you closed it, and check under sinks and around the cylinder for leaks.
If the pressure has fallen, the unit shows a fault, or the house will not come up to temperature within a day or so, call your installer rather than resetting it repeatedly.
If you would like your controller set up with sensible away settings, or want to check frost protection is enabled, our engineers can do it as part of a visit or survey.
