Ceiling mounted heating radiator (C) Carson Dunlop

Guide to Diagnosing Uneven Heat in Rooms Served by Radiators, Baseboards & Convectors
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Why do different radiators or baseboards heat unevenly in a building?
How to identify, inspect, diagnose, and repair problems with hot water or steam radiators, baseboards, or heating convectors
How to inspect, diagnose, and repair problems with steam radiators
If your radiator or baseboard is cold and the heating system is "on" - here we diagnose the problem
Questions & answers about how to diagnose and fix uneven heat problems in buildings with hot water heat

This article describes the diagnosis & repair of cold heating baseboards, convectors, radiators, or steam radiators. We provide articles that help in diagnosing and repairing no-heat problems with each types of hot water or steam or fan convector heat delivery systems.

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© Copyright 2010 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.

Explanations for Uneven Heat - Mixed Systems of Radiators & Baseboard Heat

This website answers most questions about all types of heating systems and gives important inspection, safety, and repair advice. If you don't know what kind of heat your building uses, we explain how to figure out the answer at HEATING SYSTEM TYPES. If your heating system is not working properly, see NO HEAT - BOILER or NO HEAT - FURNACE.

Mixed radiator and baseboard heat systems (C) Carson Dunlop

As Carson Dunlop's sketch (left) shows, a mixed heating distribution system that combines cast iron radiators (or wall convector units) with heating baseboard in the same heat distribution piping loop can produce uneven performance.

The heating system's behavior will also be affected by the location of the thermostat. In our sketch, the heating control thermostat is located near the radiator.

Because cast iron radiators take longer to get hot in response to circulating hot water in the system than does finned-tubing baseboard, the room where the baseboard heat is installed will be very hot, maybe too hot, early in the heating cycle (while the radiator is heating up).

Then as the thermostat (located near the radiator) is satisfied and stops the boiler or circulator pump from sending hot water through the heat distribution piping, the hot, high-thermal mass cast iron radiator will continue to warm the room where it is located, while the room with the finned-tubing baseboard will cool off more rapidly.

The result may be that the room heated by the finned-tubing baseboard will be sometimes "too hot" and other times "too cold".

Advice for regulating steam heat to improve even heat delivery in a building is found at RADIATOR STEAM VENTS, AUTOMATIC

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Questions & answers about how to diagnose and fix uneven heat problems in buildings with hot water heat.

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Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. (416) 964-9415 1-800-268-7070 info@carsondunlop.com. Thanks to Alan Carson and Bob Dunlop, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education including the ASHI-adopted Home Inspection Training Program (home study course), publications such as the Home Reference Book, report writing materials including the Horizon report writer, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.

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.

RADIATORS
  BANGING HEATING PIPES RADIATORS
  BASEBOARD, CONVECTOR, RADIATOR TYPES
  COLD HOT WATER BASEBOARD / RADIATOR
  COLD STEAM HEAT RADIATORS
  LEAKS at BASEBOARD, CONVECTOR, RADIATOR
  RADIATOR or CONVECTOR COVERS
  RADIATOR or CONVECTOR INSULATION
  RADIATOR STEAM VENTS
  RADIATOR STEAM VENTS, AUTOMATIC
    Install Steam Vents to Control Heat
  RADIATOR VALVES & HEAT CONTROLS
    Radiator Control Valves & Vents
    Manual Radiator Valves
    Hot Water vs Steam Radiator Valves
    Adjust Level of Heat
    Automatic Radiator Valves
  STEAM TRAPS
  UNEVEN HEAT DIAGNOSIS

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

Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.

The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ^® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.

Carbon Monoxide Gas Toxicity, exposure limits, poisoning symptoms, and inspecting buildings for CO hazards
DUST CONTAMINATION FROM HVAC? An Investigation of Indoor Dust Debris Blamed on a Heating/Cooling System Reveals Carpet Dust
Fuel Oil & Oil Heating Magazine, 3621 Hill Rd., Parsippany, NJ 07054, 973-331-9545
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.)
Links to our list of additional information on heating system inspection, repair, maintenance
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Guide to Diagnosing Uneven Heat in Rooms Served by Radiators, Baseboards & ConvectorsInspectAPedia® -

Explanations for Uneven Heat - Mixed Systems of Radiators & Baseboard Heat

Questions & Answers regarding this article

Ask a Question or Search InspectAPedia

Technical Reviewers & References

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

Guide to Diagnosing Uneven Heat in Rooms Served by Radiators, Baseboards & Convectors
InspectAPedia^® -