If you are buying a house in winter and it is occupied then the chances are that it is being heated (at least in part) and the service installations are being used. But if you are buying a house in winter which is vacant there are a few extra items which need to be checked, particularly if the water has been turned off and the heating system drained down.
If the water has been turned off you will not be able to check the water pressure, working order of the fittings, watertightness of pipework or be able to check whether the drains are flowing freely. Ask the selling agent to arrange for the vendor to turn the water on so that these items can be checked by specialists before you agree to purchase the property.
When the water is turned on, arrange for a heating contractor (contact a Gas Safe Registered contractor if the heating is gas) to inspect and test the heating and hot water system. Have its age and condition checked and make sure the boiler is a sufficient size to adequately heat the property.
If the house is damp, check whether this is simply condensation due to the house not being adequately heated and ventilated, or whether there is rising dampness or penetrating dampness. If there is rising dampness or penetrating dampness find out the specific cause/s of the dampness and deal with the defect/s. Some replastering may be required if plasterwork has been affected by salts. See also Buying a 1930s House. Consider instructing a Chartered Surveyor to report on any dampness and/or condensation issues. This can be checked as part of a detailed house survey. Visit RICS Find A Surveyor to find a surveyor in your area.
Check whether and drains or gullies have become blocked by leaves. Check whether gutters need clearing to avoid overflowing and/or rain penetration which may lead to dampness internally and staining externally.
See also Selling a house in winter.