Tankless coils are indirect water heaters that take their heat from the steam or hot water boiler that is used to heat the house. A cold-water supply pipe extends into the hottest part of the boiler water. The water in the copper tube is kept hot by the boiler water. When there is demand for hot water, water flows through the tube through the hot boiler water, and water is delivered to the fixture.

This is often seen by the home inspector as the supply conduit to outside installations, such as air-conditioning compressors.

Knob-and-Tube

Knob-and-tube wiring is so named because of the porcelain fittings used to support and insulate the conductors from the timber components in the home. The knob holds the wire away from rafters and joists, while the tubes are inserted into holes bored though joists and studs to protect the conductor and its rubber insulation.

Valleys are weak spots in roofing systems. They have a lesser slope than the adjacent roof planes. They erode faster because water is directed into them. Inspectors must look not only at visible flashing, but also at the adjacent roof covering, at least a couple of feet on either side.

Chimney Flues

While the inspection of chimney flues is a highly specialized procedure, any obvious deficiencies in the flue should be noted. In particular, pay attention to flues that are damaged, collapsed, or show signs of previous chimney fires. Extra care must be taken when inspecting chimney systems that are being used to vent fossil-fuel appliances, such as boilers, furnaces, water heaters and manufactured fireplaces, as any deficiency in either the liner or the chimney structure could be a potential fire starter, or could allow carbon monoxide into the habitable space within the home. It is now required that any traditional flues being used as vents for these appliances be fitted with continuous metal flue liners to ensure that no noxious gases can find their way into the home. Compliments of InterNachi