Navien LCB700-21RS Installation & Operation Manual page 32

Single Pipe Suction Lift with De-Aerator System
When the storage tank is below the burner, an alternative to a two pipe system can be achieved using an oil de-aerator. This effectively
removes the air from the oil supply on a single pipe lift.
The maximum suction height 3.5 metres. The oil tank must be positioned below the oil pump. Create an inlet and return loop between
the de-aerator and oil pump.
A non-return valve must be incorporated within the de-aerator or fitted to the oil line between the oil storage tank and the de-aerator.
A top feed oil tank fitted with a de-aerator using an internal non-return valve should have any non-return valves fitted in the base of the
tank to the suction line removed to assist purging air from the oil line.
The de-aerator is connected close to the boiler as a two pipe system as shown in the following illustration. Refer to the manufacturer's
instructions supplied with the de-aerator.
The de-aerator must be mounted vertically, as shown in the following illustration.
Oil
Pump
Boiler
32 Connecting the Oil Supply
De-aerator
Min. 1 m
Oil
Storage Tank
Oil Strainer and
Water Separator
Oil
Filter