This is likely to be efflorescence.

Efflorescence is the release of salts from cement whilst it is drying which forms as a white deposit that can normally be removed by wiping or brushing with a dry, stiff brush. It is important that you must not try to wash off the salts, since this may make matters worse.

Many materials used in building a house are mixed using water, such as plaster, concrete and mortar. Water will evaporate from these materials and may cause condensation. The process is called ‘drying out’ and usually only lasts for about 6 months.

The following will help;

Wipe away any condensation on windows & other glass surfaces.
Cover pans when cooking.
When possible, dry clothes outdoors.
Do not block air bricks or vents.
When possible, leave windows or trickle-vents open.
Close doors when taking a bath or shower to avoid moisture spreading.

Before contacting the appliance manufacturer, please first check the following:

Is the power switched on?
Has the fuse blown?
Has an MCB on the consumer unit tripped?
Has the oven been left in programme mode instead of being returned to manual operation?
Is the fridge freezer thermostat in the operating position?

If you are still experiencing a problem after check these items, please contact the manufacturer directly (contact details can be found in your Home User Guide).

It is always best to check with us before making a big purchase. We will have all the information to hand to understand if there are any planning requirements etc.

The stop cock can always be found under the kitchen sink.

The walls of your new home have been painted a light coat of emulsion to allow the drying out process to complete properly.
This can take between 6 to 18 months. Once the effects of drying out have ceased, the walls may be painted or papered as desired.