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OIL STORAGE TANKS
ABANDONING OIL TANKS
AGE of OIL TANK
ANODES & DIP TUBES on WATER HEATERS
BURIED OIL TANK ADVICE
BURIED OIL TANKS, FINDING
COMBUSTION PRODUCTS & IAQ
DEFINITION of Heating & Cooling Terms
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECTORY of OIL TANK EXPERTS
FILTERS, OIL on HEATING EQUIPMENT
FIRE SAFETY CONTROLS
FLOATING UP OIL STORAGE or SEPTIC TANKS
FLOODED HEATING EQUIPMENT REPAIR
FLOODED WATER HEATER REPAIR
FUEL OIL TYPES & CHARACTERISTICS
FUEL UNIT, HEATING OIL PUMPS
GALVANIC SCALE & METAL CORROSION
GAUGES ON HEATING EQUIPMENT
HEAT TAPES, Heat, Insulation prevent Freeze-Up
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HEATING OIL CLOUD WAX GEL POINT
HEATING OIL EXPOSURE HAZARDS, LIMITS
HEATING OIL - OLD, USEABLE?
HEATING OIL PIPING TROUBLES
HEATING OIL SHELF LIFE
HEATING OIL SLUDGE
HEATING OIL TANKS
HEATING OIL TYPES & PROPERTIES
HEATING OIL USAGE RATE
HEATING SYSTEM NOISES
HOME BUYERS GUIDE TO OIL TANKS
NOISE CONTROL for HEATING SYSTEMS
NOISES COMING FROM WATER HEATER
ODORS & SMELLS DIAGNOSIS & CURE
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FUEL TYPES & CHARACTERISTICS
OIL ODORS, LEAKY OIL TANK PIPING
OIL SPILL CLEANUP / PREVENTION
SOOT on OIL FIRED HEATING EQUIPMENT
STAIN DIAGNOSIS on BUILDING INTERIORS
THERMAL TRACKING & HEAT LOSS
VIDEO GUIDES: Heating System Videos
VIDEO GUIDES - InspectAPedia.com
WINTERIZE A BUILDING
Oil burner filters: here we explain the installation, use, maintenance, and repair of oil filters used on oil-fired boilers, furnaces, and water heaters. We discuss tracking down air and oil leaks at or near the oil filter canister and we describe proper oil filter location and problems to check for during oil filter cartridge changes.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Why do we need an Oil Filter at Oil Burner?
This oil burner fuel piping article series describes defects in heating oil piping, filters, safety valves, and oil tank fill and vent piping. All of these oil storage tank and piping installation defects can easily be found by visual inspection. We include considerations of oil pipe leaks out (fuel oil leaks), oil piping leaks in (air in the system), clogged, damaged, noisy, or mis-routed fuel oil piping, and oil fill and vent piping size and location requirements. We also discuss the need for and location for heating oil or fuel oil filters and safety valves.
Beyond the costly problem of leaky oil piping, this document lists other important safety or oil-fired equipment operational defects in home and light commercial heating oil storage and piping systems. If your heating appliance fuel is LP gas or natural gas, see GAS PIPING, VALVES, CONTROLS.
Modern heating oil quality varies depending on the oil fields from which the crude oil was refined. In much of North America a significant portion of heating oil comes from Venezuelan crude which produces a more tarry product than product from the Arabian oil fields.
A shift to alternative oil sources began in the 1970's oil crisis. A result is that oil fired heating equipment that had worked fine for decades with no oil filter installed began failing due to oil fuel unit (oil pump) strainer clogging and oil burner nozzle clogging.
As a result, today all oil-fired heating equipment such as home heating boilers, furnaces and water heaters should have an oil filter installed.
Best Oil Filter Location
Sometimes the oil filter is installed at the oil storage tank outlet but the most common and recommended installation location is shown in our photographs at page top and above: the oil filter is installed close to the oil burner where it is easily accessible for service and where it filters oil immediately before the heating oil enters the oil burner assembly.
Location of Fire Safety Controls at the Oil Filter
The best place for the fusible link oil valve (Fire-o-Matic Safety Valve™ for example) is on the oil supply line just before the inlet to the oil filter canister (red arrow, below left), not between the canister and the oil burner as shown at below right (orange arrow). This allows the service tech to shut off oil just before the filter canister in order to open the canister and change the oil filter cartridge.
With the shutoff valve between the filter canister and the oil burner (above right), changing the oil filter in the canister will require the service tech to go to the more distant oil tank to find and close a valve in that location (if one is even present).
Bad, Dangerous, or Stupid Locations for Heating Oil Filters
Servicing the Oil Filter: Step by Step Procedure for Changing the Heating Appliance Oil Filter Cartridge
The oil filter cartridge should be changed during oil heating equipment annual cleaning, service, and tune-up. You should not have to change oil filter cartridges more often. If the cartridge clogs and leads to service calls or heat loss between annual service calls then we suspect the oil tank is contaminated with water or sludge - problems that need to be corrected at the oil tank.
The procedure for changing the oil filter cartridge is simple, but if it's performed improperly you could be left with no heat.
Once you have installed the new oil filter cartridge inside the canister you will need to bleed air out of the canister and filter before restoring the system to service. If your heating oil tank is at a level higher than that of the filter itself this is an easy task.
With your catch-basin below the oil filter canister, simply loosen or remove the air bleeder screw located on the canister top just before the canister outlet fitting (red arrow in our photo at left, courtesy of reader E.S.).
Then open the oil supply valve to permit oil to flow from the oil tank into the canister. You may hear or feel air escaping at the air bleeder opening.
Once you see a clear flow of heating oil at the bleeder opening you can replace the screw that closes that port.
Watch out: don't forget to include the fiber washer that seals the screw to the canister head or you may have oil or air leaks at the canister.
At OIL FILTERS on HEATING EQUIPMENT we described changing the oil filter as part of oil burner maintenance. And there we warned about leaks in piping fittings at the burner and at the oil filter canister assembly. Here are the details.
Oil piping leak at the copper piping flare to iron piping connection.
Where Do We Usually Find Leaks at the Heating Oil Filter Canister Assembly?
Here are more illustrations of places where we often find leaks at heating oil filters: at the canister air bleed screw (not tightened, stripped threads, or failure to install a fresh gasket), at the canister top center bolt (same), and at the joint between the oil filter canister lid and base.
The oil filter assembly shown in the photos below was in deed leaking. But it took a bit of work to find out exactly where the problem was. Because oil flows from a leak anywhere on the canister top down the canister sides, you can be fooled about exactly where the heating oil leak is occurring. That's why an expert cleans and dries all of the surfaces meticulously. That makes watching for leaks easy.
We examined the connections at the inlet side of the oil canister, the flare itself and the IPT threaded fitting entering the canister lid (above left). We examined the filter mounting bolt at the center of the canister lid (above right).
Other tricks for finding an oil leak include using tracer powders on the cleaned surface, pressure tests, and even a paper towel on the floor below suspected drip points.
Next we examined the air bleed screw (below left) - ultimately we found both the center top bolt loose and the air bleed screw loose - the heating service tech had just forgotten to check & tighten them.
At above right we indicate where you will often find wet heating oil - in the gap between the canister lid and canister base. But this is a confusing "wet oil" location. It could be wet in this spot for the following reasons:
Below at Frequently-Asked Questions (FAQs) about Heating Oil Filters on Boilers, Furnaces, Water Heaters we describe these oil filter leak points and how they occur in still more detail.
Installing Duplexed Parallel Oil Filter Canisters - A Pair of Oil Filters Handles Oil Tank Sludge
A solution that was far less costly than changing out the sound but sludgy indoor oil storage tank was the installation of duplexed oil filter canister cartridges.
As shown in our photo at left, we installed the filter canisters side by side and routed piping so that they operated in parallel, not in series. (In series the first filter clogs and shuts down the system and the second filter is not helping.)
The copper oil line feeds a fusible-link oil valve shown at the left side of our photo. The oil piping then feeds a tee that in turn connects to two high-capacity oil filter canisters (center of the photo). The outlets of each oil filter canister feed back into a common line that exits through a second tee, passes by an oil pressure (vacuum) gauge, and then connects by a flexible line to the oil burner inlet port.
Once installing this system we had no more heat outages due to oil filter clogging between annual service calls.
Watch out: generally it's preferable to remove sludge from an oil tank rather than add oil filters. In this case we had our oil company service technician check the indoor oil storage tank soundness (see OIL TANK TESTING) before we elected to install the duplex oil filter system shown here. Had the tank not been sound it would have had to be replaced.
See OIL TANK SLUDGE for details about methods for correcting this problem.
Frequently Asked Questions (FAQs) about Heating Oil Filters on Boilers, Furnaces, Water Heaters
Watch out: leaks in heating oil appliance piping or filters can be much more serious than just a drip spot on the floor. The same leak that allows oil to drip out of the oil filter or piping connections allows air to be drawn into the system when the oil fuel unit (oil pump for the water heater, oil fired boile or furnace) is running. That air leak into the system results in improper oil burner operation, soot clogging, and even a loud bang at oil burner start-up or worse, a dangerous puffback. Detailed explanation of why an oil line leak causes a bang or puffback at the oil burner, and loss of heat is at OIL LINE LEAKS - Oil Line leaks found
Question: Why is my oil filter canister leaking oil - apparently from the bottom of the unit?
I recently replaced my oil filter (I actually replaced the entire oil canister with a new oil canister that included the filter already inside of it). The burner is working properly, the flame is on,and I'm getting hot water.
The problem is that I seem to have a small/minor leak from the oil canister itself. Oil is dripping from the canister (I think it's leaking from the bottom of the canister). I've checked all the fittings to make sure they're not loose. They're all tight, as are all the connections in and out of the oil canister.
Do you know why the oil canister could be leaking? Was I supposed to tighten the bolt/screw that's on the bottom of the canister (underneath the filter) as well? I assumed the oil canister came ready to install and that I wouldn't have to adjust the top or bottom bolts on the canister.
Any idea why the oil canister is leaking oil (from the bottom)? - Thanks, Ed Salva
Thanks to Mr. Salva for the Mitco oil filter canister photo (above left). Mr. Salva's photo illustrates an important detail: place a suitable container below the oil filter canister to catch any spills before you attempt to service the unit.
Reply: Check for missing or damaged fiber washers and o-ring as well as leaky flare fittings
Where to leaks occur at heating oil filter canister assemblies?
If you never have opened the oil filter canister, I'd shut off oil at the fire-o-matic valve between canister and oil tank, turn off the oil burner of course, and open the canister - to be sure it contains a filter and to be sure that all of the gaskets and o-rings are in place and un-damaged.
At OIL TANK PIPING & PIPING DEFECTS you'll find more about oil piping and filter leaks, photos, and suggestions.
In the article above (at OIL FILTERS on HEATING EQUIPMENT) you will see photos of the filter canister type I'm discussing.
Send me a photo of your filter/canister as it may be a different brand or model than what I describe above.
Continued from Ed:
Thanks for the quick response. I have to say that this website has a TON of valuable information!
I'm at work now but when I get home I'll try to attach a picture of the oil filter. It actually looks very similar to the one in the picture on this website (the picture under "HEATING OIL FILTER - NONE - No Oil Filter Installed on Oil Fired Equipment"). The silver one.
I replace the filter yearly on my burner. This year, I decided to change the whole canister as I felt it needed to be changed (it's the original canister that was installed 8 years ago). Then I ran into the problem of oil leaking from the oil canister.
When I first replaced the oil canister a couple of days ago, that's when I noticed the oil leak. I thought immediately that I had bought a defective oil canister. So I decided to take it apart. Surprisingly, everything in the canister was intact (filter, o-ring, etc). Then I went back to the hardware store and purchased ANOTHER oil canister and installed this new one. Same problem, oil leak from bottom of oil canister.
That's when I started researching and came across this site and posted my question.
Can the nozzle have anything to do with this leak? It's not a major leak, just a few ounces per day. Nonetheless, any oil leak is not good and I want to stop the leakage if I can on my own.
When I got home last night, I took some pictures of the oil canister.
Continued from DF:
Ed mail photos using the CONTACT link found at top, left, or bottom of our web article pages.
I agree with taking care not to strip threads. Using a sealant can help avoid trying to fix a leak just by tightening. Also FYI iron pipe threaded fittings are tapered so that the fitting gets tighter as it is turned inwards.
But that means that every time you disassemble and re-use a fitting it has to be turned in further than before to get tight. In turn that means on some devices a fitting can bottom out or reach end of threads without being satisfactorily tight. That's why plumbers often will not re-use brass-to-steel fittings such as the adapter on your filter canister inlet and outlet sides. If you disassemble and reassemble, it's cheap to use a new fitting plus leak-lok.
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