Your ducted heating vents may look like well-sealed units but lift a lid and you may be surprised to to find that not all is as it appears.
When you turn your heater on, warm air rushes through the ducts into your house but also draws freezing cold air in from the underfloor space though the gaps around the duct. (quack quack). This doesn’t make for really energy efficient heating.
Grab the caulking gun and seal the gap so you can heat your house without cooling it at the same time.
Trickiness Rating: EASY.