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Guide to Heating Oil Burner Fire Safety Valves: fusible link oil piping shutoff valves InspectAPedia®  -     What is a fusible-link fire-safety valve, and how are they used on oil fired heating equipment: boilers, furnaces, and water heaters? Where should oil line fire safety valves and check valves be located? Where should the heating system electrical shutoff switches be located? Links to articles on other oil heat safety controls

This document describes defects in heating oil safety valves and electrical switches. All of these oil storage tank and piping installation defects can easily be found by visual inspection. 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. Our complete list of heating equipment controls can be found in the following articles: BOILER CONTROLS & SWITCHES and FURNACE CONTROLS & SWITCHES. Also see FIRE SAFETY CONTROLS and see DRAFT REGULATORS, DAMPERS, BOOSTERS.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

How & Where do We Install a Fusible-Link Firematic™ Oil Safety Valve?

The Firematic fusible-link automatic oil line shutoff valve (photo at left) should only be present on the oil supply line. This is a manual or automatic valve that will stop the flow of oil in the oil line.

This valve controls flow of fuel oil to the oil burner of heating boilers, furnaces, and water heaters.

Fusible link Oil Valve: Oil line safety valves have a lead or other soft metal core that melts and closes the valve so that the system won't keep feeding oil to the heating equipment if the area is on fire. See our photo at below left for an example of a Firematic™ safety valve right at the oil burner. Synonyms: Fire-o-Matic valve, Fusible link valve, oil line shutoff valve, oil safety valve, and Fireamatic valve.

The standard oil safety valve used at the oil burner and often found also at the oil tank is the Firematic™ fusible link safety valve. The Firematic™ oil line valve can be installed in ANY position - (vertical, horizontal, upside down) at least that's what we were taught and what we have seen - the valve is spring loaded. In a fire a lead core melts at 165 degF and a spring in the valve assembly snaps the valve shut to assure that the heating system does not feed oil to a building fire. It has to work in any orientation.

Watch out! A simple oil line shutoff valve may not be a fusible-link safety valve. The simple shutoff valve might be any plumbing valve that can manually stop oil flow in the line, but it is not a safety device.

Make sure you've installed a fusible-link safety valve at each location where it's most needed - at each oil burner. Even when one of these valves is installed at the oil tank the proper place for this protection is right at the burner as well. Why?

In the event of a fire, if the return oil line valve closes before the supply line oil valve your oil burner pump may burst the oil line or it may cause a fuel pump gasket or seal to fail, leading to uncontrolled oil flow and perhaps worse, spray heating oil everywhere, possibly feeding the building fire. Thanks to Dave Ferris for this fire safety tip and thanks to reader Rick Johnston for adding clarification.

Suntec points out in their installation literature for fuel units (oil pumps for oil burners) that pressures over 10 psi on an oil inlet line (normally running at a vacuum) may damage the shaft seal on the pump - i.e., leak heating oil.

SAFETY warning: If the oil line fire safety valves are missing or are not at the right location, we recommend immediate installation of a Fire-o-matic™ type oil line safety valve on the oil line at the burner.

• An oil line shutoff valve at the oil tank or at another remote location away from the oil burner is also a good idea, such as at the building wall where an outdoor oil tank line enters the building, or right at the oil tank (photo at above right - this oil tank valve is leaking).
  
  
• An automatic oil line shutoff valve right at each and every individual oil burner: (a type that will shut off oil supply to the heating equipment in the event of a fire, such as a Fire-o-Matic™ valve) for example if your heating system and also your hot water heater each has its own oil burner. (Photo above left). A common but poor practice is to install an oil valve just at the oil tank or perhaps at the oil burner for the heating boiler but not for the oil fired water heater in the same building.

Fire Safety for Two-Line Oil Piping Systems

If two oil lines are used to supply an oil burner, Do NOT install an automatic oil line shutoff on the return oil line between the oil burner and the oil tank. Use a check valve instead. The automatic oil line shutoff valve should only be present on the oil supply line. Further explanation is below.

SAFETY WARNING: If oil line valves are missing or are not at the right location there is risk of system malfunction, oil leaks, and fire damage. We recommend installation of a Firematic fusible link (Fire-o-matic)™ type oil line safety valve on the oil line at the burner. This valve controls flow of fuel oil to the burner, and has a lead core which melts and shuts the valve, stopping the flow of oil in event of a fire in the building.

Even when a fusible link oil line valve is installed at the oil tank, the proper place for this protection is right at the burner as well. A valve in that location also makes servicing the heating equipment easier, faster, and cleaner.

Where do we Put the Check Valve on a Heating Oil Line?

If two oil lines are used to supply an oil burner, install a fusible link oil line shutoff valve only on the oil supply line at the oil pump on the oil burner. Do NOT install an automatic oil line shutoff on the return oil line between the oil burner and the oil tank.

Use a check valve instead. Check valves like this one permit oil to flow just in one direction. They do not close down in event of a fire. Installed on the oil return line a check valve permits oil to flow from the oil pump back to the oil tank. This makes service easier since we won't spill oil backwards out of the return line when working on the oil burner. Check valves suitable for placement on the oil return line are available from various oil heat equipment producers including Webster.

The valve shown at left should not be used as a check valve in the application we just discussed. This is a Webster OSV & requires a vacuum to open. If installed in the return line the valve would be pressurized, not open, cause the shaft seal to rupture or blow out & result in a major oil leak. Thanks to reader Rick Johnston for adding clarification.

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

BOILER CONTROLS & SWITCHES
DRAFT REGULATORS, DAMPERS, BOOSTERS
FURNACE CONTROLS & SWITCHES
OIL TANK PIPING DEFECTS
  CAULK PIPE ENTRANCES
  FIRE SAFETY CONTROLS
  HEAT TAPE HAZARD ON OIL TANK
  OIL FILL & VENT
  OIL FILL PIPE EXPOSED
  OIL FILL / VENT PIPE CAP LOST
  OIL FILL & VENT PIPES UNDERSIZED
  OIL FILTER - NONE
  OIL LINE EXPOSED
  OIL LINE SINGLE, UP HIGH
  OIL LINE SINGLE ON BURIED TANK
  OIL LINE LEAKS
  OIL SAFETY VALVES
  OIL TANK FILL & VENT LINES APART
  OIL TANK VENT PIPE MISSING

Other Oil Heat Safety Controls & Devices

Other safety devices include flame sensors, temperature sensors, reset switches, limit controls, aquastats, and similar terms. See:

BOILER CONTROLS & SWITCHES
  Air Bleeder Valves
  Air Separator Purge Valves
  Aquastat Functions
  Cad Cell Relay Switch Flame Sensors
  Circulator Pumps & Relays
  Draft Regulators, Barometric Dampers
  Expansion Tanks
  Gauges on Heating Equipment
  Limit Switches, Boilers
  Low Water Cutoff Valves, Boilers
  Mixing Valves
  Pressure Gauges, Boilers
  Relief Valves - TP Valves
  Reset Switch - Primary Control
  Reset Switch - electric motors
  Spill Switches
  Stack Relay Switch
  Water Feeder Valves, Hydronic Boiler
  Zone Valves

• Thanks to Alan Carson and Bob Dunlop, Carson Dunlop, Associates, Toronto, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education, publications, report writing materials, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
• Dave Ferris - M&S Environmental Systems, Dutchess County, New York. Mr. Ferris was an HVAC expert. Personal communication to DJF 1987. Remove the firematic or fusible oil supply line valve on return oil-line side - in case of fire if this one closes first the pump continues to run, blows its seal, and sprays oil all over the fire. Proper installation is to have a fusible link valve only on the supply side, and to install a check valve on the return line to prevent back-siphonage from the tank.
• Thanks to Rick Johnston for pointing out that the more likely cause of a fire safety valve in the return oil line is a burst seal on the fuel unit 4/6/2009
• "The Oil Safety Valve (Service)", Charles Bursey, Sr., Fuel Oil News, February 2006 (Still trying to get the full article - October 2008 - DF) Charles W. Bursey Sr. can be reached at F.W. Webb Co. www.fwwebb.com/
• "Installation Information for Suntec A-2000, A-7000 Single Stage and B-8000 two stage fuel units"Suntec Industries, 60 Aberdeen Drive, Glasgow KY 42141, 270-651-7116 (1725 rpm black label, 3450 rpm white label)
• Tigerloop: oil line de-aerator devices, Westwood Products Inc., 330 William St., PO Box 610, South River, NJ 08882-0610 - (732) 651-7700 email@westwoodproducts.com

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• Oil Tanks - The Oil Storage Tank Information Website: Buried or Above Ground Oil Tank Inspection, Testing, Cleanup, Abandonment of Oil Tanks
• Abandon a Buried Oil Tank, How To - Abandoning Commercial Underground Tanks, Russ Brauksieck, ASHI Tech. Journal, Vol.3 No.1 Spring 1993, P. 40-41 [Reprint]
• Above Ground Oil Tanks: Visual Inspection of Oil Storage Tanks for evidence of leaks, damage, improper piping - photos and text
• Above Ground Oil Tanks Checklist, an Oil Company's advice
• Above Ground Tanks UL Standards, UL Tank Listing Standards, guidance for home owners, buyers, and inspectors
• Buried Oil Tanks - Finding How to Find Buried Oil Tanks and "Nearly Hidden" and Leaky Oil Tanks - photos and text.
• Buried Fuel tank - Advice - Buried FUEL Tank - GAS or OIL advice for home buyers, inspection report language
• Environmental Issues & Regulations for Oil Tanks, Registration, Abandonment, Leak Reporting
• Home Inspection Report Language Library: Buried Oil Tanks, Basic home buyer advice - home inspection report language suggestions
• Home Inspection Report Language Library: Visible Defects in Oil Tank Installations, Tanks, and Heating Oil Piping
• Home Inspection Report Language Library: Gas Fuel Piping or Tank Faults Basic advice - home inspection report language suggestions
• Home Inspection Report Language Library: Oil Tanks text file list © Oil and Other Storage Tank Leaks, Testing, Abandonment, Inspection - UST home inspection report language files - Reference List
• Indoor Environment Website Indoor Building Environmental Hazard Detection, Testing, Repair, & Prevention - Main Web Page
• Leaky Heating Oil Tanks - Advice for Home Owners or Buyers: caused of leaks in oil tanks, oil tank testing alternatives, what to do about leaky tanks: D.J. Friedman, ASHI Tech. Journal, Vol.2 No.1, Winter, 1992 p. 42-43 Illus
• Leak or Failure Rates for Home Heating Oil Tanks
• Legal Issues Regarding Buried Oil Storage Tanks K.S. Rea, Attorney, summary from ASHI Chapter Seminar.
• Primer on Petroleum Bulk Storage Tanks & Petroleum Contamination of Property Paul H. Ciminello, ASHI Tech. Journal, Vol.3 No.1 Spring 1993, p 35-39
• Petroleum Bulk Storage J. Sibblies, NY State DEC, Advice to Home Owners and Home Inspectors about Oil Storage Tanks - summary from ASHI Chapter Seminar.
• Septic Tank inspection, testing, diagnosis, repair
• OIL TANK FAILURE CAUSES - Oil Tank Failure Causes - oil tank leaks are caused by corrosion, damage, soil conditions, other factors
• TANK FAILURE RATES - Oil Tank Failure Rates - Oil Tank Leak Probability as a Function of Tank Age, Location, Condition, Soil Conditions and Other Factors
• OIL TANK TESTING - How Oil Tanks are Tested for Evidence Leaks, of Current or Previous Oil Spills
• ...

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