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Here we explain simple procedures for determining whether the circulator pump is working on a heating system. This article series discusses Circulator Pumps: how to find, inspect, diagnose, and repair problems with Hot Water Heating System Circulator Pumps
or circulator pump relay switches and controls.
This article series answers most questions about Heating System Boiler Controls on central heating systems to aid in troubleshooting, inspection, diagnosis, and repairs.
How to tell if the circulator pump is working - some circulators are quiet - which pipes to feel
Hot Water Heating System Circulator Troubleshooting & Repair Guide: we discuss circulator pumps, circulator pump relay switches & controls on heating systems to describe how to tell if a heating circulator pump is working. Some examples of questions and problems that show up first as a symptom:
Why do some heating zones work and others not?
Why does heat come out of zones where thermostats are not calling for heat?
How to fix an air-bound heating system and blocked circulator pump.
Is the circulator pump running? If the motor runs that doesn't mean that the pump is actually moving hot water through the system.
First Things to Check in Diagnosing a Bad Circulator Pump
First, before checking the circulator pump for proper operation, we need to be sure that the heating system controls are calling for heat:
1. The heating boiler must be turned on and able to run
2. The thermostat must be set up to call for heat
3. In response to the thermostat you should hear the heating boiler turn on and run;
4. You can then examine the heating system distribution piping leaving and returning to the heating boiler, identify the circulator pump (or pumps if there is more than one), and feel the heating water piping at the pump(s).
5. Identify the circulator for the heat zone where you have turned up the thermostat:
Check the Operation of a Single Hot Water Heat Circulator Pump - a Single Heating Zone
If there is only one thermostat, one heating zone, and one circulator pump it's simple, there is nothing to sort out, continue with INDIVIDUAL HEAT ZONE CHECK. There will be no zone valves, just a single pump and its controls to turn the circulator pump on and off.
The heating distribution piping in a one-zone building may still be divided into multiple "branches" or sub-loops. If that is the case, you might be able to convert this system to individual zone controls by adding zone valves at the individual heating water piping loops - provided that the loops are arranged in parallel, not in series.
Check the Operation of a Multi-zone Heating System Using a Single Circulator Pump
Multiple thermostats, multiple heating zones, one circulator, multiple Zone Valves:
[Click to enlarge any image]
If there are multiple thermostats there may still be only one circulator (if zone valves are installed) and individual heat zones are controlled by motorized zone valves that open or close to let heating water flow through that heating pipe loop.
In that case the same procedure as below for "feeling the circulator piping" is used but you feel the piping at the zone valve as well - since if a zone valve is not opening no hot water will flow.
Our photo (left) shows a 6-zone hot water heating system using six individual zone control valves and a single circulator pump.
See ZONE VALVES, HEATING for details about how these devices work and how they are inspected and repaired.
Check the Operation of a Multi-zone Heating System Using Multiple CIrculator Pumps
Some buildings use one circulator pump (and controlling circulator relay switch) to control each individual heating zone (instead of "zone valves" as above).
In this case if you don't know which circulator pump and pipe loop supplies the zone for which you turned up the thermostat, just go to INDIVIDUAL HEAT ZONE CHECK just below, but feel the piping at each circulator pump.
Our photo (left) shows an 8-zone hot water heating system using eight individual Bell & Gossett™ circulator pumps. Notice those rust marks at the bottom pump flange at some of these units?
All eight pumps had been installed in the previous two years - at a previous inspection we found the predecessor pumps leaking so badly that the floor of the boiler room was puddled with heating water. The installer needs to inspect, clean, and re-make the leaky connections on these new circulator pumps to avoid a repetition of the same problem.
Individual Heating Zone Operation Checks
How to know if a particular hot water heating zone is working or calling for heat:
Listen to the circulator pump: is it running? Bell & Gossett circulators are generally audible, making some electrical motor noise. Grundfoss circulator pumps are quieter but should be audible. Taco circulator pumps are often so quiet that you cannot rely on sound (or I can't), but it's easy to go on to the next step: feeling piping temperatures.
Incidentally if a heating zone circulator pump is very noisy or has become more noisy than when it was installed, there may be a problem with a failing motor bearing, pump assembly bearing, or pump impeller.
Feel the Hot Water Heat Piping at the Circulator Pump: You can feel the pipe at the circulator pump - doesn't matter which side - in or out flow - since if the pump is running the pipe will get warm, then hot.
If the circulator is on the pipes that are LEAVING the boiler and sending heat into the building (not the best location) it's better to feel the pipe on the outlet side of the circulator since the pipe at the inlet side might be hot just by convection heat rising from the boiler.
If the circulator pump is on the RETURN side of the heating piping loop (the usual and better location) then you can feel the pipe at the circulator pump - doesn't matter which side - in or out flow - since if the pump is running the pipe will get warm, then hot if it is successfully moving hot water out of the boiler and through the heating pipes.
Why Might Multiple Heating Zones All Run at Once When Only One Thermostat is Calling for Heat?
If all of the heating system's valves stopped working some time ago, someone may have latched them in the "open" position - so if any of the thermostats called for heat, every heating zone would receive heat even though only one thermostat is calling for heat.
See ZONE VALVES, HEATING for details about zone valve operation, inspection, diagnosis, repair. There we include photos including a zone valve control lever on the side of a Honeywell valve - in the auto position.
If you see that the manual zone valve control lever is "latched" into the "on" position, try un-latching it and then watch to see if the valve operates (and the lever moves) in response to a call for heat at that zone.
Watch out: hot water may be circulating in a hydronic heating system even if no thermostat is calling for heat, for example if a Flow-Control check valve has stuck in the open position or has been left manually open. See CIRCULATOR PUMP WON'T STOP RUNNING for details.
Continue reading at CIRCULATOR PUMP LEAKS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
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circulator pump not heating first floor but higher floors get heat
(Feb 16, 2015) Mirso Dragovic said:
I have a 2-1/2 story building with 1 hot water baseboard system feeding both the first floor and second floor apartments. 1 circulator pump with no zoning valves. The problem I'm having is the first floor is about 10 to 15 degrees warmer than the second floor. I have the high limit temp set to 200 degrees and the water pressure set to 25lbs. I'm wondering if the circulator pump is working correctly, or should I be looking at something different. I have bled the radiators on the second floor and are getting hot.
Thank You in advance
Not sure if I should have left my email: email@example.com
Since in a 2 story 1 zone home warm air wants to rise upstairs by convection usually we have the opposite trouble, too Mapuche heat upstairs.
Often the plumbers install manually adjustable flow balancing valves on each heating piping loop to permit adjusting the flow rate of hot heating water to these different areas. Ask your heating service tech to find and adjust these to get more heat where you want it, or to install them if needed.
Also take a look at the thermostat location, as that could be part of the problem.
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"Installation and Operation Instructions, Raytherm Residential Boilers," courtesy of Raypak®, and technical advisor Wayne Hoffman, personal communication 5/11/2009. Mr. Hoffman is a technical advisor with more than 30 years experience in the heating field. Raypak is a Rheem company that provides hydronic heating boilers for residential, pool, and commercial use. Raypak can be contacted at 866-583-0664 for technical support or for assistance in selecting the proper heating equipment for a specific application.
Rheem Corporation is a manufacturer of water heaters and heating equipment including Ruud heating and cooling products.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & 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 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.)
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: firstname.lastname@example.org. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, 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. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones