Heating home in winter while vacant


I own a house in Burgundy / Bourgogne / Yonne district and I just received a shocking electricity bill. My property manager left the electric panels (5 total) on all winter at the setting shown and my bill for the year was euro1636 TTC. YIkes. I have seen conflicting advice on whether to leave the heat on at a minimum level during winter, on frostgel, or not at all. I turn off the water and open all taps / spouts to drain and drain the water heater tank and toilets. I also have a recently installed VMC although not sure how to switch it on / off or tell if it is running. FIrst winter (2016-2017) was ok - some mold but nothing too crazy. WInter 017-18 had mold damage that had to be remediated thus for 2018-2019 I ran the heat on low. MY service is at 12V / HC/HP tarriff bleaue. The house is about 250 years old and I assume no insulation. No clue about the double glazing (windows were installed post 2000)

. Measures I know I can take include insulation in the attic and perhaps roof of the cellar as well as getting an actual door fitted for the cellar. I will be calling edf tomorrow to see if there is a cheaper option for me. I was there 3 weeks in the past year.

So should I leave the heat on and, if so, at what settings? Would it be useful at all to run only the top floor heaters (where the mold damage was) or would they just run longer and not create any energy savings? Although there is a timer I am not sure if it actually functions. The panel is wired into wall, not plugged in. ANy advice on how these actually work would be helpful as well. Do they cycle on and off to maintain a certain temperature or just run continuously?

Lots of questions :slight_smile: Thanks you for any and all suggestions. Merci beaucoup toute le monde.

Also, I am from the US.


I have just answered a similar thread - I think often its humidity that causes issues so a dehumidifier may be more useful than heating.

This was my response -

Last year we experienced mould in the house - dry and green all over the worktops, tables and sofas.
The conclusion was it was the humidity change from winter to a wet spring. Heating would not have resolved that completely. When we arrived in December 2018 we bought a dehumidifier with us, this proved to be very good as on the first day we had 85% humidity, over the course of thee days and emptying the container twice a day, it reduce to around 55% humidity.
We have a converted barn so there is little natural ventilation, it has not been an issue since as we air the house and are here for good (hopefully).

Our dehumidifier has a drain so in theory you could run the drain hose to a shower trap or sink and therefore have it on timer perhaps.

Hi Laurie and welcome to the forum.

If you have a property manager - would it be possible for him/her to leave some of your windows open behind closed shutters during those winter days when it is not actually pouring with rain.

Locally, that is how most folk keep empty houses damp free. The air circulates and keeps the place fresh. Of course, during a spell of wet, the windows are shut.

When the winter sunshine is at its best, both shutters and windows are flung wide open wherever possible and the sun warms the rooms.

Just a thought.


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Thanks. Not sure where I would put the humidifier as it could only drain into the shower and Im not sure it would be enough for the whole 3 story house. I do but those moisture absorbing pellets out as well as cat litter…

Thanks, That would be ideal however the PM charges $50 per visit. I have friendly neighbors who would monitor for me. Unfortunately I do not have shutters…

Good grief… I hope you get your money’s worth :upside_down_face:

Friendly neighbours are how it works here. Not quite so easy if you don’t have shutters though.

However, it might be feasible on sunny days - which do happen in winter. Giving the house a regular airout might well solve the problem, it will just need careful monitoring to ensure the windows are closed at night.

I think you and your neighbours need to share a bottle or two and chat this through…:upside_down_face::wink::relaxed::relaxed::relaxed:

Don’t underestimate the reduction of heating costs by reducing the humidity. We run a single dehumidifier in a 4 bedroom house and it makes a huge difference to the temperature also as well as reducing damp issues.

Thanks - what type do you have? Do you leave it running during long absences or are you there throughout the year? Would it allow me to have the heat off during winter months when I am not there or at least on a lower setting?

The PM is about an hour away but I have shared bottles with my neighbors and they are more than willing to help keep an eye on the place ! Do most people heat during periods of vacancy where you are or just rely on the occasional airing out? THanks!

In the village, we never heat the empty houses, just do the windows. There’s a group of us who have taken on the role of guardians - folk are so nice, it is a pleasure to help them.

In the outlying hamlets I have no idea and, frankly, it will depend on the individual property.

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You would still need to heat the house.

When our house was a holiday home we always left the dehumidifier running when we were not there - left it on the kitchen sink draining board draining into the sink.

Just check Amazon for well reviewed ones and make sure you can add a drain pipe (or preferably comes with the pipe).

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Thanks! Good advice I don’t want mold issues again…

Just a thought - normally the houses have everything switched off when empty, along with local guidelines from Insurers.

I honestly have no idea of it makes any differences, but if you are intending to leave stuff ON - make sure there is nothing in your Insurance policy that says otherwise.

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Excellent point. I tried to access my insurance policy first thing this am to see what the guidelines are for vacancies but it was not available online due to technical issues to be resolved soon…

Another issue with something like a dehumidifier is can it survive a power cut and remain on the same setting when power resumes? A lot of modern electronics will be off in that situation. So you want a device with more manual controls or someone that will reset it to how you want after a power cut.

I can’t politely say how I feel about people leaving their heating on over winter! :face_with_symbols_over_mouth:The only good thing is the size of their
bills may help them seek other, better alternatives.


I notice that there is no door to your cellar. That could be allowing dampness from the cellar to permeate the house.

One home I guard, used to have mould appear, quite regularly, on the wooden kitchen furniture, no matter what I did.

One particular winter, loads of rain, more than normal and I decided to check the cellar. Always well aired as we left that door open.

Ooops, I found water ingress through the bottom of the stone walls and the ancient shallow dip which ran around the outer edge of the floor, was awash. Turned out there was an ancient outlet and that was blocked.

OH helped me with a makeshift job and when the family came in the Summer we got the whole thing properly dealt with.

Never before actually seen water in the cellar, but quite probably the damp getting into the cellar, during the winter, was the cause of damp air getting into the house. But, I stress, never seen any water apart from that one time.

Maybe you have a similar thing happening in your cellar. We did chuckle when we realised the reason for the shallow dip around the walls - obviously a 17th century home improvement.

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You have to leave it on a frost setting at least. We used to set ours to 7 degrees anything less and mould would start to grow on everything - then discovered dehumidifiers also.

I should have mentioned that, once the cellar drain was cleared, we continued with the normal winter “airing” of the property (with cellar door closed) and have never again had mould on the kitchen furniture - yeah - Result !!! :smiley::smiley::smiley:

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A VMC should be sufficient once building issues have been identified.