Checklist of Critical Defects in Air Conditioning or Heat Pump Systems
A/C - HEAT PUMP CRITICAL DEFECTS
- CONTENTS: Air Conditioning (or Heat Pump) Critical Defects are listed here. List of A/C problems that can be observed by visual inspection. Examples of A/C or heat pump problem reporting language for inspection reports
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Air conditioner defect checklist:
Here we list the types of critical problems that may occur in air conditioning or heat pump systems, a first step in understanding how an air conditioning service technician will diagnose
certain common air conditioning system failures or defects.
This air conditioning/heat pump inspection guide lists critical air conditioning system defects which a building inspector or owner should not miss. We include photographs to assist readers in
recognizing cooling system defects. This HVAC article series describes the inspection, diagnosis & repair of residential air conditioning systems (A/C systems) & heat pump systems to diagnose problems as well as to inform home buyers, owners, and
home inspectors of common cooling system defects.
Critical Defects in Air Conditioning Equipment Inspections
Beginning at AIR CONDITIONING & HEAT PUMP SYSTEMS the major components of an air conditioning system are
described, sketches and photographs are provided, and common defects for each cooling system component are listed along with visual or other clues that may
suggest a problem or probable failure of A/C components.
Example home inspection report language used to report air conditioning system defects and
cooling system repairs needed is provided to describe
common air conditioning system defects. We continue to add to and update this text as new details are provided.
Critical defects which an inspector should not fail to detect when examining any building component or system
are defects which form an immediate, significant safety hazard or defects which are quite likely to involve
significant repair or replacement cost, and which involve components or systems which are necessary to occupy
and use the building. Methods for detection and diagnosis of these defects are discussed in this document
and in its references. Suggestions for inclusion or exclusion of items in this list are invited - see the
link "Contact Us".
Function: Cooling is delivered to only part of the building, e.g. only to one floor.
See DUCT SYSTEM DEFECTS
Air Duct System Safety: Unsafe return air intake which may draw in carbon monoxide at heating equipment.
See DUCT SYSTEM DEFECTS. Note that more indirect building defects and hazards, such as a toxic airborne mold reservoir or toxic gases or chemicals (such as sewer gas) may be picked up and distributed through a building from one area to another by duct system defects.
Uneven air supply resulting in uneven temperatures especially on the first floor of a two story house with ductwork between the first and second floor.
See DUCT SYSTEM DEFECTS
Air Conditioning System Safety: Unsafe electrical wiring: aluminum branch circuits and FPE Stab-Lok or Zinsco circuit breakers may have been used to power the compressor. Look for evidence of overheating or over fusing
at the service cutoff and in the electrical panel and at the service cutoff by the compressor/condenser [This item is not agreed-on as a critical defect by all reviewers] For details see:
ALUMINUM WIRING HAZARDS - aluminum electrical wiring often burns-up at high-amperage electrical connections such as air conditioner wiring.
Federal Pacific Electric (FPE) FPE Stab-Lok Circuit Breakers can increase the risk of a fire if these breakers are used on air conditioning or heat pump equipment
Zinsco Electrical Circuit Breakerss: overheating, failure to trip, burn-ups involving Zinsco and certain Sylvania electrical panel components. These components can also increase the risk of a fire if these breakers are used on air conditioning or heat pump equipment
Air Conditioning System Operation Report Language
Observation of the condition of an air conditioning or heat pump system, typical inspection report language includes these succinct descriptions
... The cooling system operated normally at the time of our inspection.
... Caution: The equipment was not run and therefore not tested
... outside temperature was estimated to be at or below 50 degF.
... the system has been "shut down" for some time.
... In cold weather operation could damage the compressor, particularly if it has been left "shut down".
... Individual components were not operated - see note below.
... Any deficiencies noted were based only on visual inspection. We did no
... electrical, gauge or pressure tests on this equipment.
Operating Note: Many such air conditioning systems must be left with power turned on (we found switches in the "off" position) for 24 hours prior to running the equipment. This permits heaters at the compressors to assure good oil flow in those components. To operate
the equipment without this step risks very costly damage to the compressor.
When a system is not operated we can make no representation that it functions correctly and adequately.
... We recommend that you ask the owner about the condition of this equipment.
... If weather permits, it should be checked by an HVAC service person and returned to operating status prior closing sale
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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.
"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]
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. 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