Sticking or Jammed Air Conditioner Thermostatic Expansion Valve
How to Fix an A/C or Heat Pump TEV that's not working, won't cool, warm air flow
TEV STICKING REPAIR - CONTENTS: repair of a jammed thermostatic expansion valve (TXV or TEV) at new air conditioner or heat pump installations. Data about & contact information for KeepRite air conditioners & Tempstar air conditioners & heat pumps
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
Sticking or jammed thermostatic expansion valves:
In addition to debris, dirt, or icing problems that occur in TEVs or thermostatic expansion valves, sometimes the thermostatic expansion valve on brand new air conditioners may need an extra jolt to get it working, as we explain here.
Sticking Air Conditioner or Heat Pump Thermostatic Expansion Valves at New Installation
At TEV INSTALL & REPAIR where we list various troubles with thermostatic expansion valves and suggest diagnostic and repair procedures we noted the following:
[Click to enlarge any image]
Sticking TEV valves:The TEV and also AEVs depend on a little oil or oil mist flowing along with refrigerant to lubricate the interior of the valve.
Occasionally debris in the refigerant system can cause the TEV to jam, chatter, or fail to perform properly.
But we suspect that a more common cause of TEV valve sticking is the freezing of a droplet of water at the needle valve, holding it stuck. The valve stops working properly.
But as we learned from Ontario reader E.T. and her HVACR installation and service company, TEVs may be "sticky" right out of the box from the manufacturer. At left: a KeepRite™ air conditioner compressor / condensing unit, newly installed.
The installer used a simple "overcharge" procedure to free the TEV as we describe in this reader report.
Reader Question: new KeepRite® air conditioner not working well: does not cool the house
I placed a comment on the InspectApedia website last night about my new air conditioner not working well. Here are the photos you asked for. Our house is 980 square feet with a finished basement. I have closed all the vents in the basement.
We live in Ontario and are having fluctuating temperatures. Today it is 72F outside with an expected high of 85. I turned the air conditioner on yesterday when the outside temp was 65F and the temp inside my house was 78 because it had been a hot day and the air conditioner was not able to bring the temperature down.
I set the thermostat for 72F. It took 5.5 hours to bring the temp down to 76F, which is when we went to bed. Thorough the night it managed to bring the temp down to 72. In the morning I turned the thermostat up to 73 and the air conditioner has not stopped running, even momentarily, since I got up this morning. The couple of times I woke through the night it was running as well (I have a young baby).
I was not given a manual, only an invoice for the unit and the work done. It was installed 4 weeks ago. We had the ducts cleaned 3 years ago and they do need cleaning again - I have an appointment booked for Friday. If you would like to see the emails that were exchanged with the installer I can forward them to you.
Thank you very much for getting back to me so quickly. I appreciate that I am able to ask questions this way. - E.T. 7/21/2014
Reply: why doesn't the installer fix their installation SNAFU?
I see in your photos a newly installed air conditioning system that by your description certainly is not cooling.
Your additional photo (left) shows that a refrigerant-drier was installed, though I can't tell from the image if it's in the right direction or not. The flow direction is marked plainly on the canister label.
Something as simple as failure to adequately clean (pull a vacuum) and filter the refrigerant system could cause the system not to cool even if the compressor and air handler themselves seem to be working.
It's usually easy to diagnose a new system by checking refrigerant charge, pressures, temperatures, and current draw. Why didn't the installing company return to fix it?
Enlarging your third photograph of the data tag on the KeepRite condenser / compressor unit (shown at below left) gives us more information about this unit.
The Product model number begins with N4A318K ... which is the same as found on Tempstar® R-410A refrigerant air conditioning compressor / condenser units in the N4A3 series. These units use a Copeland® compressor and are factory-charged with R-410A refrigerant.
It's possible that your KeepRite® air conditioner is using the same equipment components, re-branded with the KeepRite® name.
Decoding the Model Data on a KeepRite® Air Conditioning Compressor / Condenser Unit
Since you were given no information whatsoever about your equipment, not even an installation/operation manual we're providing some data here.
Decoding the KeepRite® product number, N4A318KC100, based on TempStar's data (cited below)
N = "Tempstar Entry" brand ( KeepRite®-branded equipment, according to the manufacturer cited below, uses a product nomenclature beginning with a K, such as KMHA050 H2- HT4A-A)
4 = Refrigerant is R-410A
A = Air Conditioner (H would indicate a heat pump)
3 = SEER = 13
18 = 18,000 BTUH or 1 1/2 tons of cooling capacity
K = Voltage code 208/230V - 1- 60 (single phase 60 cycle)
Reader Follow-up: sticking thermostatic expansion valve on new AC installations
I had the oven on for approximately 20 minutes at lunch time. The inside temp has risen and is staying at 76F although it is 72F outside and I have the thermostat set for 73. The air conditioner still has not stopped running. We have two dogs, our ducts do need cleaning as I mentioned before. But we did have it done 3 years ago.
Can this affect the air conditioner functioning to this extent? The unit is obviously working because it did finally bring the temp down through the night and maintained it this morning - but why it's struggling so hard is unclear to me.
The A/C installer did identify the problem and he came back to fix it.
I'm relaying the information that I recall from what he told us so it may not be perfectly clear, but he said the diaphragm on the TY [TEV or Thermostatic Expansion Valve- Editor] valve (??i think) was sticking on the new installs and causing it to not be seated properly.
When he contacted the manufacturer they advised to overcharge the system and force it open further, which would cause it to then close properly and seat the valve.
I hope I got the information right, as this seems to be an innate problem with these units and I would hope that this information could be useful to someone else down the road.
I also want to say that I found this website just through a Google search when we were having the issues with the A/C and I was feeling desperate that something had to be wrong and was being told that it probably wasn't. You provide an invaluable service allowing yourself to be contacted with questions and providing service to others the way you do. It's a very generous thing to do and do and I, for one, am grateful that you took the time to respond. Thank you very much!
I was very glad that our install person kept coming back and looking into the issue and finally got it fixed.
Reply: Expansion Valve SNAFUs
Indeed even a small amount of dirt or debris in a new refrigeration system can foul up the thermostatic expansion valve causing it to fail to operate properly. If the installer is making an error in cleanliness during initial installation, or if s/he forgets to install the proper refrigerant filter/dryer on the refrigerant lines, or if the refrigerant charge is incorrect the TEV may jam or fail to open and close properly. Of course it's true that the TEV itself could be defective.
The result is failure to release refrigerant at the proper rate into the cooling coil in the air handler. In turn that would allow the air handler to run without adequately cooling the building.
Reader Follow-up: using a refrigerant "overcharge" to clear a stuck TEV
Our air conditioner installer installed an identical unit to ours (a Keeprite) at another customer's house this week and was having the same issues as us. He contacted the manufacturer and was told that there is an issue in that model with a valve not closing properly on installation. The unit needs to be overcharged which forces the valve open so that it snaps shut. He came tonight to do just that and it seems to be cooling.
I will be able to send more information about the specific valve etc when my husband gets home as he understands it better than I do, but I wanted to send an update to let you know that the problem has been found and in a case anyone writes in with a similar issue.
Reply: watch out for refrigerant overcharging
Watch out: The overcharge needs to be removed lest the compressor motor be destroyed.
Watch out: warranty coverage: You should register your product to assure proper warranty protection, and you should obtain the owners or installation manual for your air conditioner from the installer or if that contractor cannot help you, use the contact information we provide above to contact the company. Our search of the KeepRite websites we found did not provide links to manuals or installation guides for equipment matching your product number.
You had told me that the overcharge needs to be removed, so I checked and he did remove it at the time.
Company Contact Information for KeepRit®e & TempStar® air conditioning & heat pump product types & series
KeepRite® Heating & Cooling Products, Website: http://www.keeprite.com/ (At this website the company does not provide an address, company information, nor contact information). The KeepRite website does cite HVAC contractors in West Chester OH, USA, and Toronto, Ontario, Canada. Other contact information for KeepRite® Refrigeration is at http://k-rp.com/node/149, Factory telephone: 1-800-463-9517 Email for Warranty claims: warranty@k-r0pcom Customer Support Email: email@example.com
The KeepRite® compressor/condenser unit features a two-stage scroll-type compressor motor and the company cites a 10-year warranty.
Continue reading at TEV INSTALL & REPAIR - the air conditioning system seems to be "running" but not enough cool air, or no cool air at all is being delivered to the occupied space. or select a topic from the More Reading links shown below.
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Ask a Question or Search InspectApedia
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Home Inspection Education Home Study Courses - ASHI@Home Training 10-course program. 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 Home Reference Book, a reference & inspection report product for building owners & inspectors. 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.
The Home Reference eBook, an electronic version for PCs, the iPad, iPhone, & Android smart phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter inspectaehrb in the order payment page "Promo/Redemption" space.
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.
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.
 "Air Conditioning & Refrigeration I & II", BOCES Education, Warren Hilliard (instructor), Poughkeepsie, New York, May - July 1982, [classroom notes from air conditioning and refrigeration maintenance and repair course attended by the website author]
 Thanks to Mark Cramer, Tampa Florida, for assistance in technical review of the "Critical Defects" section and for the photograph of the deteriorating gray Owens Corning flex duct in a hot attic. Mr. Cramer is a Florida home inspector and home inspection educator.
 Thanks to Jon Bolton, an ASHI, FABI, and otherwise certified Florida home inspector who provided photos of failing Goodman gray flex duct in a hot attic.
 Thanks to Scott at SJM Inspect for suggesting this EPA document and for technical editing remarks regarding our air conditioning website,
SJM Inspection Service LLC, serves the entire state of CT, sjminspect.com 203-543-0447 or 203-877-4774
 Thanks to Joe Panimondo for technical editing, April 2011
 This website discusses these air conditioning and heat pump terms and problems: Air Conditioners: Central Air Conditioning Troubleshooting & Repair Guide: How to Inspect, Diagnose, & Repair Central Air Conditioning: Defects in A/C compressors, air handlers, duct work, and controls. We explain how to inspect & repair central air conditioning systems and for homeowners we also answer basic HVAC questions such as what are the basic air conditioning components? We provide guidance in determining air conditioning cooling capacity & energy efficiency, Troubleshooting air conditioning compressor problems, Diagnosing air conditioning air handler problems, Air conditioning condensate problems, Duct system inspections, defects, repairs, Cleaning air conditioning equipment & A/C refrigerants.
 HVAC brands discussed include but are not limited to: Lennox, American Standard, Amana, Everrest, Goodman, Frigidaire, Coleman and Gibson. Brands of related air handling equipment
include Honeywell, Aprilaire, White-Rogers, Broan. Nutone, Fantech, Venmar, Arzel, Hi-Velocity, Vanguard, Wirsbo, Weil McLain, Unico, Heat Link, A.O. Smith, Water Furnace, ClimateMaster, Geo-Excel, Command Aire, Friedrich, LG, Mitsubishi, Sanyo, Hart &
Cooley, Munchkin, Superstor Ultra, Lochinvar and Knight HVAC equipment.
 HVAC Employment: U.S. Department of Labor website describes HVAC jobs and the employment outlook for HVAC technicians.
 HVAC Education, Training Accreditation agencies: Quoting the U.S. DOL HVAC website above:: After completing the programs below, new technicians generally need between 6 months to 2 years of field experience before they are considered proficient. Three accrediting agencies have set academic standards for HVACR programs:
 HVAC Excellence. 1701 Pennsylvania Ave NW,
Washington, DC 20006 Tel: (800) 394-5268. Quoting: HVAC Excellence is a not for profit organization that has been serving the HVACR industry since 1994. It is our goal to improve competency through validation of the technical education process. By setting standards and verifying that they have been met, we inspire the industry to excel. We know that all of the challenges that face our industry are achievable by continuous improvement in the way that we prepare technicians.
 National Center for Construction Education and Research, 3600 NW 43rd Street, Bldg. G, Gainesville, FL 32606, Tel: 888.622.3720, Quoting:
NCCER is a not-for-profit education foundation created to develop industry-driven standardized craft training programs with portable credentials and help address the critical workforce shortage facing the construction industry.
 The Partnership for Air-Conditioning, Heating, and Refrigeration Accreditation, (PAHRA)
2111 Wilson Blvd., Suite 500
Arlington, VA 22201-3001
(703) 524-8800, Quoting: The Partnership for Air-Conditioning, Heating, Refrigeration Accreditation (PAHRA) is an independent, third party organization that is a partnership between heating, ventilation, air-conditioning and refrigeration (HVACR) educators and the HVACR industry that will award accreditation to programs that have met and/or exceeded industry validated standards. This programmatic accreditation program is the only one that is supported by the major industry associations.
Licensure. Heating, air-conditioning, and refrigeration mechanics and installers are required to be licensed by some States and localities. Requirements for licensure vary greatly, but all States or localities that require a license have a test that must be passed. The contents of these tests vary by State or locality, with some requiring extensive knowledge of electrical codes and others focusing more on HVACR-specific knowledge. Completion of an apprenticeship program or 2 to 5 years of experience are also common requirements.
In addition, all technicians who purchase or work with refrigerants must be certified in their proper handling. To become certified to purchase and handle refrigerants, technicians must pass a written examination specific to the type of work in which they specialize. The three possible areas of certification are: Type I—servicing small appliances; Type II—high-pressure refrigerants; and Type III—low-pressure refrigerants. Exams are administered by organizations approved by the U.S. Environmental Protection Agency, such as trade schools, unions, contractor associations, or building groups.
HVAC Training Courses, Schools: HVAC Technician Training Schools [http://technicianschool.net/hvac-technician-training-schools/], lists the following schools offering technical courses may offer specific training programs for potential careers, including HVAC technicians. Among HVAC schools that website lists are
Everest Colleges [http://www.everest.edu],
Florida Career College
7891 Pines Blvd
Hollywood, FL 33024
2299 Vauxhall Road
Union, NJ 07083
NOTE: when considering an HVAC training course or school, check the HVAC education accrediting associations listed above.
 Ratib Bakera is member of Refrigeration Service Engineers Society (RSES), an International
training organization for the HVACR industry provides educational and certification programs to HVACR professionals of all experience levels. www.rses.org provides information on the organization and its training materials. Independent testing and certification of HVAC technicians is provided by North American Technician Excellence - NATE - see www.natex.org.
NATE is supported by ASHRAE, the US EPA, and a host of other trade and professional associations.
 Singer brand HVAC equipment brand history: Singer was bought by & became the climate control unit of Dallas-based Snyder General Corp. (founded by a former Singer HVAC manager) in 1982. The name Singer was dropped in 1984. In 1984 Snyder General operations included Arcoaire, Comfortmaker, and McQuay. In 1991 Snyder General sold Arcoaire & Comfortmaker to Inter-City Products. In 1994 Snyder General was acquired by Hong Leong Group Malaysia. Snyder General is at 2001 Ross Avenue Dallas, TX 75201.
 Lennox air conditioning and heat pump owners manuals for air conditioners, air handlers, furnaces, heat pumps, indoor air quality systems, packaged units, water heaters, zone controls and other controls such as thermostats, are provided by Lennox at http://www.lennox.com/support/manuals.asp
 Air Diffusion Council, 1901 N. Roselle Road, Suite 800, Schaumburg, Illinois 60195, Tel: (847) 706-6750, Fax: (847) 706-6751 - firstname.lastname@example.org - www.flexibleduct.org/ - "The ADC has produced the 4th Edition of the Flexible Duct Performance & Installation Standards (a 28-page manual) for use and reference by designers, architects, engineers, contractors, installers and users for evaluating, selecting, specifying and properly installing flexible duct in heating and air conditioning systems.
Features covered in depth include: descriptions of typical styles, characteristics and requirements, testing, listing, reporting, certifying, packaging and product marking.
Guidelines for proper installation are treated and illustrated in depth, featuring connections, splices and proper support methods for flexible duct. A single and uniform method of making end connections and splices is graphically presented for both non-metallic and metallic with plain ends."
The printed manual is available in English only. Downloadable PDF is available in English and Spanish.
 Engineering toolbox properties of water - http://www.engineeringtoolbox.com/water-thermal-properties-d_162.html and email: email@example.com web search 09/16/2010
 Owens Corning Duct Solutions - www.owenscorning.com/ductsolutions/ - provides current HVAC ductwork and duct insulating product descriptions and a dealer locator. Owens Corning Insulating Systems, LLC, One Owens Corning Parkway, Toledo, OH 43659 1-800-GET-PINK™
 "Flexible Duct Media Fiberglas™ Insulation, Product Data Sheet", Owens Corning - see owenscorning.com/quietzone/pdfs/QZFlexible_DataSheet.pdf "Owens Corning Flexible Duct Media Insulation is a lightweight, flexible, resilient thermal and acoustical insulation made of
inorganic glass fibers bonded with a thermosetting resin."
"Air Conditioning & Refrigeration I & II", BOCES Education, Warren Hilliard (instructor), Poughkeepsie, New York, May - July 1982, [classroom notes from air conditioning and refrigeration maintenance and repair course attended by the website author]
 FlowKinetics LLC, 528 Helena Street
Bryan, Texas 77801 USA, Tel: (979) 680-0659, Email: firstname.lastname@example.org, Website: www.flowkinetics.com, "FKS 1DP-PBM Multi-Function Meter
Pressure, Velocity & Flow
User’s Manual", web search 07/16/2012, original source: http://www.flowkinetics.com/FKS_1DP_PBM_Manual.pdf [copy on file] and "FKT Series Flow Measurement And
Pressure Acquisition System
User's Manual" http://www.flowkinetics.com/FKTSeriesManual.pdf [copy on file]
 Histoire de l'Académie royale des sciences avec les mémoires de mathématique et de physique tirés des registres de cette Académie: 363–376. Retrieved 2009-06-19.- Pitot Tubes, Henri Pitot (1732)
 Wikipedia provided background information about some topics discussed at this website provided this citation is also found in the same article along with a " retrieved on" date. NOTE: because Wikipedia entries are fluid and can be amended in real time, we cite the retrieval date of Wikipedia citations and we do not assert that the information found there is necessarily authoritative.
"Pressure sensor", retrieved 7/16/2012
 "GE Zoneline® Owners Manual and Installation Instructions, Heat/Cool Model 2900, Heat Pump Model 3900", General Electric Corporation, [copy on file].
 "GE Zoneline® Owners Manual and Installation Instructions, Heat Pump Model 5800", General Electric Corporation, [copy on file].
 N Lu, YL Xie, Z Huang, "Air Conditioner Compressor Performance Model", U.S. Department of Energy, August 2008, [copy on file as PNNL-17796.pdf] Available to the public from the National Technical Information Service,
U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161
ph: (800) 553-6847, fax: (703) 605-6900
online ordering: http://www.ntis.gov/ordering.htm
 Yinger R, R Bravo, and D Martinez. 2006 Air Conditioner Stalling Effects Study/Air Conditioner Testing
Procedures. Southern California Edison, Rosemead, California
 Bravo, R, R Yinger, and L Gaillac. 2006. Conditioner Stalling Unit Level Solutions Test Report. Southern
California Edison, Rosemead, California.
 Lu N, B Yang and Z Huang. 2008a. Evaluation of Southern California Edison Air-Conditioner Stalling
Solutions. PNNL-17686, Pacific Northwest National Laboratory, Richland, Washington.
 Danny S. Parker, John R. Sherwin, Bart Hibbs, "Development of High Efficiency Air Conditioner Condenser Fans", ASHRAE Transactions June 2005, [copy on file as FSEC-CR-1674-05.pdf]
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
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.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.
Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment
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.
"Air Conditioning & Refrigeration I & II", BOCES Education, Warren Hilliard (instructor), Poughkeepsie, New York, May - July 1982, [classroom notes from air conditioning and refrigeration maintenance and repair course attended by the website author]