Oil Furnace - 2-Pipe Install

Oil Furnace

Re: 2-Pipe Installation

An oil furnace can be installed with either a single oil line or with two oil lines connected to the fuel-oil pump.

► On an installation where the oil can flow from the tank to the pump by gravity (the tank must be located higher than the pump), a one-pipe system can be used, i.e. a suction line and no return line.

► On an installation where the tank is below the level of the pump the oil must be lifted. Most commonly used for this application is the two-pipe system, i.e. both a suction and a return line.

Fuel oil pumps will typically have multiple inlet ports and one or more return/bypass ports.

IMPORTANT! When converting to a 2-pipe installation, it is necessary to install a bypass "allen" screw inside the pump, under the return/bypass plug.

• The bypass screw missing will prevent the pump from pumping.
• If converting back from a 2-pipe to a single-pipe system, the "allen" screw must be removed.