4installation & operation manual | dlv heating system
2.1 OIL PLUMBING INSTALLATION
2.1.1 OIL SUPPLY
Installing a short, straight oil supply line with a minimum of ow restriction is the most important step
toward ensuring heating system longevity. When installing the DLV oil supply line, refer to the following
HOTSTART guidelines:
• Due to the increased viscosity of lubrication oil, the oil supply line must be as short and as
straight as possible. Any 90° elbows will reduce the maximum recommended oil supply length.
See Table 1 for HOTSTART DLV oil supply recommendations:
NOTE: Each additional pair of 90° elbows will reduce the maximum recommended line length by ve feet (1.5 meters). To
minimize ow restriction, HOTSTART recommends using sweeping bends or 45° ttings.
• At a minimum, size the oil supply line per the pump inlet. NOTICE! Do not reduce the supply
line inner diameter; pump seal damage will occur.
NOTE: To maximize ow and allow the longest possible supply line, install the largest practical inner diameter hose; for most
installations, HOTSTART recommends using a hose with a size larger inner diameter than the pump inlet.
• Install the oil suction port as low as possible in the oil sump, typically near or on the third
inspection cover. NOTICE! Avoid installing the oil suction port in a location that may allow
debris or sediment to enter the heating system.
• HOTSTART recommends installing a customer-supplied, swing-type or full-ow check valve to
prevent oil owing into the sump. Install the check valve as close to the oil supply port
as possible.
2.1.2 OIL RETURN
When installing the DLV oil return line, refer to the following HOTSTART guidelines:
• At a minimum, size the oil return line per the pump outlet. NOTICE! Do not reduce the return
line inner diameter.
• Install the oil discharge port near the engine oil pump (typically at the P-pipe before it enters the
main engine block) or to the opposite end of the oil sump.
Table 1. HOTSTART recommended hose inner diameters, line lengths and elbow counts for
DLV oil supply lines.
PUMP
INLET
HOSE INNER
DIAMETER MAX. LINE LENGTH MAX. ELBOW
COUNT
1 inch NPT 1-1/2 inch 20 feet (6 meters) 4
1-1/2 inch NPT 2 inch 20 feet (6 meter) 4
