Liquid Fuel Storage
Liquid Fuel Storage Failure & How to Prevent It:
Part 5 - Service Procedures
This article is fifth in a series on
proper tank selection, installation
and maintenance. It is based
on the National Oilheat Research
Alliance (NORA) Advanced Fuel
Storage Tanks Gold Certification
course and manual authored by
John Levey, NORA, Director of
Education and John Donohue,
Special Projects Coordinator, Fuel
Merchants Association of NJ and
J. Donohue Associates, LLC. The
course and manual are available,
at no charge, at Learning.
NORAweb.org
The article contains recommendations
and procedures for service
technicians to follow when servicing
a home liquid fuel storage tank.
Technicians should always protect the
customer’s property with newspaper
or builders paper. It takes just a few
minutes and can make the cleanup
much easier.
Anytime that a filter, pump or fuel
line fitting is disassembled, drip pans
or trays should be placed underneath to
prevent any leaked fuel from staining or
damaging the floor and leaving an odor.
Wipe down the heating equipment
with a clean rag or cloth.
Don’t use dirty rags for this
purpose as they can leave an odor
and possibly result in a callback.
Sludge Call
Examine the filter cartridge,
canister and the fuel assembly
components for evidence of water.
Whenever water is detected, it
should be removed from the tank,
to the extent practicable, and
properly disposed.
When possible: (note: if the filter is
located at the tank, start with #2)
1. Disconnect the fuel line from the
inlet of the filter. Connect a pushpull
pump to the line and draw fuel
through the line until clean fuel flows
freely.
2. Replace the filter element & gaskets.
(or spin-on filter)
3. Disconnect the fuel line from the
fuel unit. Connect a push-pull pump
to draw fuel through the line until
clean fuel flows freely between the
filter and the fuel unit.
4. Clean or replace the pump strainer.
Completely remove the existing fuel
unit cover gaset and install the correct
new gasket.
5. Reconnect the fuel line and bleed air
from the fuel unit.
6. Check the running vacuum. Compare
the reading to the expected
operating vacuum calculated using
the following formula:
• 1" for every foot of vertical lift
• 1" for every 10 feet of horizontal run
• 1" for the filter
• 2"- 4" for an OSV valve
If the reading exceeds calculated
vacuum, there may be a restriction in
the line. Inspect the exposed line to see
whether it has been damaged, kinked or
crushed. If a defect is found, replace the
line. Never attempt to repair a damaged
fuel line. If the line appears to be in good
condition, try using the push-pull pump
again and re-check running vacuum after
clearing the obstruction.
If the unit is part of a two-pipe system,
consider converting it to a one-pipe system.
Doing so will reduce the amount of
fuel being filtered by over 90%. This can
reduce the need for filter replacement.
When converting a fuel unit to one-pipe
operation, be sure to remove the bypass
plug if the pump has one and consider
installing a fuel de-aerator.
For a one pipe system—if the filter needs
replacement more than twice a year, a
more permanent remedy may warrant
consideration.
Filter clogging may be a symptom of
bacteria in the fuel which can cause microbiologically
induced corrosion. If the
sludge problem persists after the tank has
been cleaned the fuel should be tested
and treated as needed.
Out of Fuel
When an automatic delivery customer’s
tank is out of fuel, it is extremely important
to determine why before making a
delivery.
First, measure the tank to determine
that it actually is “dry.”
If it is established the tank is
empty, office personnel should
research when the tank was last
filled and determine if it was currently
due for delivery.
If the tank was due for delivery,
the technician can deliver enough
fuel to restore operation until a
delivery can be made.
If the tank is reported to have
been recently filled or wasn’t due
for a delivery, additional research
is required. Could a recent deliv-
Always protect the customer’s property ery have been made to a different
8 ICM/March/April 2021