InspectAPedia ^®

Heating Boiler Components Dictionary & Parts Guide
InspectAPedia^®  -    

• How to Identify the Components of Hot Water Heating Boilers - A Guide to Hydronic Heating System Parts
• What are the basic components of heating boilers and hot water heat?
• How to inspect & repair central hot water heating boilers - hydronic heating

Here we explain how to Identify the parts & components of Hot Water Heating Boilers and hot water heating systems including oil burners and their parts, boiler parts, hot water baseboard and its parts, hot water radiators, and hot water convector units and their parts and controls. Each simple definition includes links to detailed articles discussing how to identify, inspect, diagnose, and repair each component of the heating system.

This website answers most questions about central hot water heating system troubleshooting, inspection, diagnosis, and repairs. We describe how to inspect residential heating systems to inform home owners, buyers, and home inspectors of common heating system defects.

Below we describe the parts and controls on heating boilers. See BOILER CONTROLS & SWITCHEST for a description of the key heating boiler operating controls and switches. If your building uses steam heat see STEAM HEATING SYSTEMS. If your building uses warm air heat see FURNACE CONTROLS & SWITCHES.

The articles at this website describe the basic components of a home heating system, how to find the rated heating capacity of an heating system by examining various data tags and components, how to recognize common heating system operating or safety defects, and how to save money on home heating costs.

Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. © 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.

A List & Dictionary of Oil Fired Heating Boiler Parts & Components

• Heating Boiler - an enclosed steel or cast iron container that uses an energy source to heat water (or make steam) that is sent through heat radiating devices in the occupied space to heat a building. Hydronic heating boilers use hot water to distribute heat through piping and baseboards or radiators. Steam heating boilers produce steam to distribute heat through one pipe or two pipe steam heat systems and steam heat radiators. Some heating systems use a hydronic boiler to heat water that is circulated thorough a heating coil inserted in the plenum of a warm air furnace heating system, using a water-to-air heating method.
• Air bleeders and air purge devices
• Automatic water feeder to provide makeup water in the sytem; note that different water feeder valves are used on a hydronic heating boiler (hot water circulates) than on a steam boiler (steam circulates)
• Baseboards - electric or hot water heat radiating devices transmit heat from hot water or steam into the occupied space; Leak stains, repairs indicating history of freeze-ups?
• Boiler flue vent connector "stack pipe" or "flue" and barometric damper
• Chimney and chimney flue
• Circulator pumps which force hot water through heating baseboards, radiators, or convector units
• Combination control - combining High Limit and "Low Limit" (which may or may not be in use depending on presence of a tankless coil)
• Draft hoods assure proper exhaust gas venting on gas-fired heating boilers
• Electric switchturniing the heating system electrical power on and off
• Expansion Tank to absorb initial system pressure increase
• Flame sensing device: Cad Cellor Stack Relay(watch for sensitive relays and learn about the re-stepping lever)
• High Limit and Low Limit (if tankless coil) separate controls on older equipment
• Low water cutoff control, a safety device used on steam boilers and some hydronic heating systems to shut down the heating boiler if its water is lost.
• Mixing valve to temper outgoing domestic hot water from a tankless coil or to control radiant floor heat temperature
• Oil Burner & oil burner parts: oil pump (fuel unit), blower, nozzle, electrodes, transformer, electric motor, air shutter, oil delay valve
• Oil Burner reset switch & oil burner motor reset switch (these are two separate controls); a reset switch may be on the cad cell relayor on the stack relay of the oil burner as well as a reset switch on the oil burner electric motor
• Oil tank, oil piping, oil valves, oil gauges
• Oil Burner Controls, aquastat: high limit, low limit, circulator controls, cad cell relay, other flame sensors
• Piping: Hot water (or steam) distribution piping and on steam systems, condensate return piping
• Piping valves: Hot water distribution piping drain and balancing valves
• Pressure Relief Valve safety device prevents boiler explosions by releasing temperature and pressure if other safety controls fail
• Pressure and Temperature gauge--12 psi cold, less than 30 psi hot. Over 30 psi dumps relief valve.(Typical operating temperature settings LO-120-160 HI-180-200 degF. Typical operating temperature observed at the gauge will be below the high, and can be as low as nighttime room temperature in non-heating season if no tankless coil is in use. The temperature/pressure gauge may help in checking for normal conditions before and during boiler operation. However the gauge can be wrong!)
• Radiators - hot water or steam. Steam: observe steam valves on each radiator and identify one pipe vs two-pipe distribution system. radiating devices transmit heat from hot water or steam into the occupied space; Leak stains, repairs indicating history of freeze-ups? Hot water radiators and baseboards may have a manually-operated air bleeder valve. Each steam radiator has a steam vent to permit steam to rise into the radiator.
• Sight glass: a glass tube used on steam boilers to give a visible indication of the boiler's water level
• Spill switchesare used to sense flue gas spillage at gas-fired equipment at the combustion gas exhaust venting systems and will turn off the heating appliance if gas spillage is detected.
• Tankless coil or a side-arm coil or other alternative ways of making domestic hot water using the heating boiler; tips about leaks, missing mixing/tempering valve, relief valve (some jurisdictions). Risk of scalding water at the house sinks/tubs if there is no mixing valve.
• Zone Valves which control hot water circulation through multiple heating zones

Share this Article      

...

Technical Reviewers & References

Search InspectAPedia

• Daniel Friedman - principal author/editor of the InspectAPedia^® Website
• InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
• Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
• Additional technical contributors & reference sources for this article are listed below.

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.

More Information on Building Diagnostic Inspections and Repairs

• Carbon Dioxide Gas Toxicity
• Carbon Monoxide Gas Toxicity, exposure limits, poisoning symptoms, and inspecting buildings for CO hazards
• Dust from HVAC? An Investigation of Indoor Dust Debris Blamed on a Heating/Cooling System Reveals Carpet Dust
• Goodman Furnace High Temperature Plastic Vent HTPV safety recall US CPSC notice
• Home Heating System Should Be Checked [for proper venting and for CO Carbon Monoxide Hazards - DJF]
• Inspection Procedures for Oil-Fired Heating Systems Detailed step by step approaches for inspecting complex systems]
• Lennox Pulse Furnace Safety Inspection/Warranty Program: Carbon Monoxide Warning
• Oil Tanks - The Oil Storage Tank Information Website: Buried or Above Ground Oil Tank Inspection, Testing, Cleanup, Abandonment of Oil Tanks
• Oil Tanks Above Ground, UL Standards, guidance for home owners, buyers, and inspectors
• Plastic Heating Vent Pipe & Other Heating Safety Recall Notices
• Weil McLain Model GV Gas Boiler/gas valve CPSC recall/repair
• Domestic and Commercial Oil Burners, Charles H. Burkhardt, McGraw Hill Book Company, New York 3rd Ed 1969.
• National Fuel Gas Code (Z223.1) $16.00 and National Fuel Gas Code Handbook (Z223.2) $47.00 American Gas Association (A.G.A.), 1515 Wilson Boulevard, Arlington, VA 22209 also available from National Fire Protection Association, Batterymarch Park, Quincy, MA 02269. Fundamentals of Gas Appliance Venting and Ventilation, 1985, American Gas Association Laboratories, Engineering Services Department. American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209. Catalog #XHO585. Reprinted 1989.
• The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
• Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
• The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
• Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
• "Residential Steam Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
• "Residential Hydronic (circulating hot water) Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
• "Warm Air Heating Systems". Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
• Heating, Ventilating, and Air Conditioning Volume I, Heating Fundamentals,
• Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
• Installation Guide for Residential Hydronic Heating Systems
• Installation Guide #200, The Hydronics Institute, 35 Russo Place, Berkeley Heights, NJ 07922
• The ABC's of Retention Head Oil Burners, National Association of Oil Heat Service Managers, TM 115, National Old Timers' Association of the Energy Industry, PO Box 168, Mineola, NY 11501. (Excellent tips on spotting problems on oil-fired heating equipment. Booklet.)

InspectAPedia® Home & Site Map - Building & Environmental Inspection, Testing, Diagnosis, Repair, & Problem Prevention Advice: In-depth research & advice on diagnosing, testing, correcting, & preventing building defects & indoor environmental hazards. Unbiased information, no conflicts of interest.

The Mold Information Center: What to Do About Mold in Buildings, When and How to Inspect for Mold, Clean Up Mold, or Avoid Mold Problems

Use this simple, economical mold test kit by following our instructions on how to collect and mail mold samples to our lab

Environmental Inspection, Testing, & Diagnosis On-Site IAQ, Gas, Air Testing, Mold Investigation, Sick Building Diagnosis, Lab Services, & Remediation Plan Preparation - indoor air quality testing, problem source determination, supporting lab work, written remediation plan addressing removal of environmental and other hazards and prevention of their recurrence.

Building Inspection, Problem Diagnosis, Forensic Investigation & Testing, Repair Consulting

Contact Daniel Friedman for website content suggestions or for fee-paid consulting