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AFUE DEFINITION, RATINGS
AGE of CHIMNEYS & FIREPLACES
AGE of AIR CONDITIONERS & HEAT PUMPS
AGE of HEATERS, BOILERS, FURNACES
AIR CONDITIONING & HEAT PUMP SYSTEMS
AIR FILTERS for HVAC SYSTEMS
AIR HANDLER / BLOWER UNITS
AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE
ANODES & DIP TUBES on WATER HEATERS
ANTIFREEZE for BOILERS
ANTI SCALD VALVES
APPLIANCE DIAGNOSIS & REPAIR
APPLIANCE EFFICIENCY RATINGS
ASBESTOS IDENTIFICATION IN buildings
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER VALVE, HEATING SYS
BACKFLOW PREVENTER, HEATER WATER FEEDER
BACKUP HEAT for HEAT PUMPS
BANGING HEATING PIPES RADIATORS
BIOGAS PRODUCTION & USE
BLOWER DOORS & AIR INFILTRATION
BLOWER FAN CONTINUOUS OPERATION
BLOWER FAN OPERATION & TESTING
BLUE vs YELLOW COMBUSTION FLAMES
BOILER CHEMICAL TREATMENTS
BOILER COMPONENTS & PARTS
BOILER CONTROLS & SWITCHES
BOILER LEAKS CORROSION STAINS
BOILER LEAKS, HOW TO LOCATE
BOILER NOISE SMOKE ODORS
BOILER OPERATING PROBLEMS
BOILER OPERATING STEPS
BOILER PRESSURE & TEMPERATURE SETTINGS
BOOKSTORE - InspectAPedia
BTU USAGE MONITORS
BUILDING SAFETY HAZARDS GUIDE
CAPACITORS for HARD STARTING MOTORS
CARBON DIOXIDE - CO2
CARBON MONOXIDE - CO
CHEMICAL TREATMENTS for BOILERS
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CHIMNEYS & Flues - Asbestos Transite Pipe
CHINESE DRYWALL HAZARDS
CIRCULATOR PUMPS & RELAYS
COOL OFF HEAT, Thermostat Switch
COMBUSTION AIR for TIGHT buildings
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ
COMPLETE COMBUSTION, Stoichiometric
CREOSOTE FIRE HAZARDS
Curved Brick Chimneys - Sulphation
CONDENSING BOILERS/FURNACES DAMAGE
CONVECTOR HEATERS - HYDRONIC COILS
DEFINITION of HEATING & COOLING TERMS
DEFINITIONS of ELECTRICAL TERMS
OIL LINE CONTROLS & VALVES
DEW POINT CALCULATION for WALLS
DEW POINT TABLE - CONDENSATION POINT GUIDE
DIAGNOSTIC GUIDES A/C / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DIRECTORY of OIL TANK EXPERTS
DRAFT HOODS - gas fired
DRAFT MEASUREMENT, CHIMNEYS & FLUES
DRAFT REGULATORS, DAMPERS, BOOSTERS
DUCT SYSTEM & DUCT DEFECTS
DUST, HVAC CONTAMINATION STUDY
DUST SAMPLING PROCEDURE
ELECTRIC MOTOR DIAGNOSTIC GUIDE
ELECTRIC MOTOR OVERLOAD RESET SWITCH
ELECTRICAL POWER SWITCH FOR HEAT
EVAPORATIVE COOLING SYSTEMS
FAN, AIR HANDLER BLOWER UNIT
FAN AUTO ON Thermostat Switch
FAN, COMPRESSOR/CONDENSER UNIT
FAN CONVECTOR HEATERS - HYDRONIC COILS
FAN LIMIT SWITCH
FAN NOISES, HVAC
FILTERS, AIR for HVAC SYSTEMS
FILTERS, OIL on HEATING EQUIPMENT
FIRE SAFETY CONTROLS
FIREPLACES & HEARTHS
FLAME COLOR, BLUE vs YELLOW COMBUSTION
FLOODED HEATING EQUIPMENT REPAIR
FLUE SIZE SPECIFICATIONS
FLUE VENT CONNECTORS
FREEZE-PROOF A BUILDING
FUEL OIL TYPES & CHARACTERISTICS
FUEL UNIT, HEATING OIL PUMPS
FURNACE CONTROLS & SWITCHES
FURNACE HEAT EXCHANGER LEAKS
FURNACE OPERATION DETAILS
FURNACE OPERATING TEMPERATURES
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
GAUGES ON HEATING EQUIPMENT
GEOTHERMAL HEATING SYSTEMS
HEAT EXCHANGER LEAK TEST
HEAT LOSS in BUILDINGS
HEAT LOSS DETECTION TOOLS
HEAT LOSS INDICATORS
HEAT LOSS PREVENTION PRIORITIES
HEAT LOSS R U & K VALUE CALCULATION
HEAT PUMPS, DIAGNOSIS, REPAIR
HEAT TAPES & CABLES on Roofs for Ice Dams
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HEATING LOSS DIAGNOSIS-BOILERS
HEATING LOSS DIAGNOSIS-FURNACES
HEATING OIL CLOUD WAX GEL POINT
HEATING OIL EXPOSURE HAZARDS, LIMITS
HEATING OIL - OLD, USEABLE?
HEATING OIL PIPING TROUBLES
HEATING OIL SHELF LIFE
HEATING OIL SLUDGE
HEATING OIL TANKS
HEATING OIL TYPES & PROPERTIES
HEATING OIL USAGE RATE
HEATING SMALL LOADS
HEATING SYSTEM INSPECT DIAGNOSE REPAIR
HEATING SYSTEM NOISES
HEATING SYSTEM SERVICE FAQs
HEATING SYSTEM TYPES
HIGH EFFICIENCY BOILERS/FURNACES
HOT WATER HEATERS
HOT WATER IMPROVEMENT
HUMIDITY LEVEL TARGET
HVAC SYSTEM TYPES
ROOF ICE DAM LEAKS
INSULATION INSPECTION & IMPROVEMENT
LOW VOLTAGE BUILDING WIRING
LOW VOLTAGE TRANSFORMER TEST
GAS LP & NATURAL GAS SAFETY HAZARDS
MAINTENANCE SCHEDULE & PRIORITIES
MANUALS & PARTS GUIDES - HVAC
METHANE GAS SOURCES
MIXING / ANTI-SCALD VALVES
MIX VALVE SCALD PROTECTION, Best Practices
MOTOR OVERLOAD RESET SWITCH
Natural Gas Combustion
NO HEAT - BOILER
NO HEAT - FURNACE
NOISE / SOUND DIAGNOSIS & CURE
NOISE AIR CONDITIONER / HEAT PUMP
NOISE, DUCT VIBRATION DAMPENERS
NOISE, HEATING SYSTEMS
NOISE, WATER HEATER
ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS FROM HEATING SYSTEMS
OIL BURNER FUEL UNIT
OIL BURNER INSPECTION & REPAIR
OIL BURNER NOISE SMOKE ODORS
OIL BURNER NOZZLE & ELECTRODES
OIL BURNERS, RETENTION HEAD
OIL BURNER SOOT & PUFFBACKS
OIL FILTERS on HEATING EQUIPMENT
OIL FILTER MISSING
OIL FUEL TYPES & CHARACTERISTICS
OIL HEAT FIRE SAFETY CONTROLS
OIL LINE CLOGGING FIX
OIL LINE QUICK STOP VALVES
OIL LINE SAFETY VALVES, OSVs
OIL FILL PIPE LEAKS
OIL PUMP FUEL UNIT
OIL SPILL CLEANUP / PREVENTION
OIL TANK ABANDONING PROCEDURE
OIL TANKS, BURIED
OIL TANK GAUGES
OIL TANK INSPECTION & TROUBLESHOOTING
OIL TANK LEAKS & SMELLS
OIL TANK PIPING & PIPING DEFECTS
OIL TANK PRESSURE
OIL TANK REGULATIONS
OIL TANK REMOVAL COs
OIL TANK REMOVAL FINANCIAL AID
OIL TANK SAFETY
OIL TANK SLUDGE
OIL TANK STANDARDS - UL
OIL TANK LEAK TEST METHODS
OIL TANK TESTING & REMOVAL COs
OIL TANK WATER REMOVAL
PLASTIC Plexvent / Ultravent RECALL
PULSE COMBUSTION HEATERS
PRESSURE REDUCING VALVES
PRESSURE REGULATOR, WATER
PUFFBACKS, OIL BURNER
PUMPS, PONY PUMPS
RADIANT HEAT Floor Mistakes to Avoid
RADIANT HEAT TEMPERATURES
RADIANT SLAB FLOORING CHOICES
RADIANT SLAB TUBING & FLUID CHOICES
RELIEF VALVE LEAKS
RELIEF VALVES - TP Valves on Boilers
RELIEF VALVES - STEAM TP VALVES
RELIEF VALVES - Water Heaters
RELIEF VALVES - Water Tanks
Reset Switch - Heater Primary Control
Reset Switch Broken - Quick RepaiR
RESET SWITCH - ELECTRIC MOTOR
Reset Switch - Stack Relays
SAFETY HAZARDS & INSPECTIONS
SAFETY HAZARDS GUIDE
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
SPLIT SYSTEM AIR CONDITIONERS & HEAT PUMPS
STACK RELAY SWITCHES
STAIN DIAGNOSIS on BUILDING INTERIORS
STEAM HEATING SYSTEMS
Thermal Expansion Cracking of Brick
THERMAL EXPANSION of HOT WATER
THERMAL EXPANSION of MATERIALS
THERMAL IMAGING, THERMOGRAPHY
THERMAL MASS in BUILDINGS
THERMAL TRACKING & HEAT LOSS
THERMOSTATS, HEATING / COOLING
THERMOSTATS, WATER HEATER
THERMOSTATIC EXPANSION VALVES
TRANSITE PIPE CHIMNEYS & FLUES
VIDEO GUIDES: Heating System Videos
VIDEO GUIDES - InspectAPedia.com
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER HEATER NOISES
WATER HEATER SCALE - De-Liming Procedure
WATER HEATER SCALE PREVENTION
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
ZONE VALVES, HEATING
How to inspect, diagnose & repair residential heating systems: these heating system articles answer questions about all types of building heating systems and describe how to inspect, diagnose, and repair heating system problems, how to cut heating bills, and heating system safety, heating system efficiency and heating trouble-shooting advice.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
In these heating system articles we explain how to inspect and detect all defects and hazards on heating systems, boilers, furnaces, and other equipment. Methods for saving on heating cost and on improving heating safety are included. Heating safety hazards such as carbon monoxide gas leaks, unsafe furnaces, furnace and boiler recalls are addressed.
[Click to enlarge any image]
Our page top photo illustrates an oil fired hot water heating boiler. The sketch at above left illustrates basic parts of a conventional gas fired warm air heating furnace; image courtesy of Carson Dunlop Associates.
The heating system inspection, diagnosis and repair articles listed at page top or at Related Topics and described below give the components of a heating system, describe how to find the rated heating capacity of an heating system by examining various data tags and components, explain how to recognize common heating system operating or safety defects, and illustrate how to save money on home heating costs. We include product safety recall and other heating system hazards.
Potentially very costly environmental hazards such as leaky oil tanks are explained in depth. Other environmental and indoor air quality topics affected by residential and light commercial heating systems are explored.
How to Inspect Heating Systems
Building HVAC (Heating, Ventilating, and Air Conditioning) have three tasks: control indoor temperature and humidity at comfortable levels, provide adequate fresh air from outdoors, and the removal of indoor air odors and pollutants by a combination of air pressure control, filtration, and exhaust ventilation systems.
But not all HVAC systems are designed to perform all three of these jobs, and in typical residential buildings separate, and un-coordinated systems may be installed to heat, ventilate, and perhaps cool the building interior.
Start a heating system inspection with basic "distant" visual observations
A proper heating system inspection begins outside with taking notice of the chimneys, flues, and vents, and for the type and location of heating equipment fuel that is used: oil tanks, LP gas, piped in natural gas, solar, etc.
Similarly, inside, before attempting a close inspection of the heating equipment itself, take not of and record defects in the heating distribution system (is there even heat present in every room?), and in the location of the heating equipment: is the boiler in a closet where it lacks combustion air, fire clearances etc. What about the oil burner shown at left - observed during a mobile home inspection (MOBILE HOME HEATING)? From just opening the bathroom sink vanity we see that an oil burner has been shoe-horned into a space where it does not belong, is unsafe, and is extremely difficult to access and service properly.
Watch out: From the moment of observing work such as the system shown in our photo, the inspector, owner, or heating service technician needs to be on red alert for amateur, unsafe workmanship.
Below and at the links listed at Related Topics we provide articles on just about any question you might have about installing, inspecting, troubleshooting, & repairing residential heating systems. Use the Website Search box at page top or the Comments Box at the end of each InspectApedia article to contact us if you cannot find information you need.
For a step by step procedure that can be used to inspect the condition of a heating system see: Heating System Inspection & Repair Procedures for Oil-Fired Heating Boilers and Furnaces where we suggest detailed step by step approaches for inspecting complex systems - a free, online, detailed heating system inspection course
Heating System Inspection & Diagnosis Detailed Articles & Education Curriculum Suggestions
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".
Because the heating system inspection and related topics discussed here cover a rather broad range, I have not attempted (yet) to list specific critical defects on this summary page. However any inspection of the condition of heating equipment in buildings must include careful attention to:
Continue reading at BOILER CONTROLS & SWITCHES or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: I'm trying to find how to determine the age of my Lennox gas furnace
I am trying to find the age of my Lennox gas, gravity fed air, furnace model GN1-105C which the only thing I've had to do to it besides cleaning is change the thermo-couple in the last 40 years
Jack, please see our article "How to Determine the Age & Life Expectancy of Heating Boilers & Furnaces" at AGE of HEATERS, BOILERS, FURNACES where we explain the decoding heating and cooling equipment data tags to learn the date of manufacture of the device. That article also refers you to some texts, including one free and visible here at InspectAPedia that offer more model/serial number decoding to see the equipment age.
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
InspectApedia has no financial connection with the sale of this book.
hi,like to know what is normal pressure range of two gauges pressure reading in heatpump running in heat mode?and is that right,when heatpump run in heat mode,the compound gauge turn in to high head pressure gauge?thanks - Jason 9/30/11
Jason, if you click on the AIR CONDITIONING link at page top you'll then find at Related Topics articles on refrigerant pressures that will answer your question.
Question: how do I identify the wall heater in my apartment?
I was wondering if I could find out what type of wall heater is in my apartment I only have the Cat no FC257, Watts 2509/1875, Volts 240. I can't make out anything else and the landlord had someone glue knobs on the heaters so I can not take the covers off I need to know if they have ever been recalled.- Kim Amundsen 11/5/11
Kim: If you like, send us some sharp photos of the heater and its data tags and I may be able to advise. Use the CONTACT link for direct email.
Question: Books & resources for heating boiler troubleshooting
Is there a book on troubleshooting residential heating boilers? Kevin 1/5/2012
Sure Kevin. In addition to the free "Diagnose ..." boiler troubleshooting & repair articles we provide (see links at page top & page left) see books listed below at the end of this article. Also we welcome specific questions and are glad to research if needed.
Question: My heating unit is running on emergency heat for the whole winter - my electric bill is too big
my problem is my heating unit have been running on emergency heat for the hole winter period and my light bill is outregious. I've had repair man come to my house and they tell me that my unit has to be run on that emergency heat because i live in a town house. What should i do im going to go broke just because my light bill is like $300 dollars. HELP!!! - Hector Toledo 2/24/2012
Hector the statement that you need to run your heater on "emergency heat" because you live in a townhouse makes no sense to me at all.
Perhaps the heating service tech just didn't give a clear explanation of what's wrong. I infer from your question that your heat is supposed to be provided by a heat pump that also provides air conditioning in hot weather.
Emergency "backup" heat in such systems is there to handle cases of unusually cold outdoor temperatures - below a certain temperature the heat pump may be unable to provide enough heat for the building and the backup heat kicks in. But in all other conditions you should not be running on "emergency" or "backup" heat.
The location, type and condition of pressure/temperature relief valve - see
The normal operating pressure and temperature of the boiler - see
If on your own, before the heating company shows up, if you see high pressure readings on the boiler gauge (30 psi or above) or if you see water spilling out of a relief valve I would SHUT OFF THE SYSTEM immediately and would get the heck out of there.
(Dec 13, 2012) qhia said:
in my reading energy saving device using capacitor bank does not function efficiently for high wattage equipment(heating)..i need to know why so confuse
These articles may help you identify and diagnose the trouble:
Question: Mobile home furnace not working
(Dec 14, 2012) Sean Newcomer said:
I have a brand new thermo pride furnace for my moble home it ran fine for two months the furnace started cylcling, it would burn then the fan would come on after a couple minutes the call to burn would shut off, then the fan would shut off a few mins later, upon fan going off the burner would cycle for heat again and the fan would come on heat would stop and so on.
But the heat keeps climbing it doesn't stop so i got ahold of the installer he told me it was the thermostat, i replaced it and still does the same its under warranty but i can't afford to pay a serve man 200.00 to come to tell me the problem. is it the burner control or is it the computer board can it be reset and how
IF the warm air output from a supply register is blowing right onto the room wall thermostat, then "the thermostat is the problem" could be a correct statement.
Otherwise I suspect a bad fan limit switch or improper installation of that control. For example, if the limit switch is mis-adjusted or if its sensor spring is binding, the system won't work properly.
Watch out: a fan limit switch that is bent, damaged, mis-handled, even mis-adjusted, can be dangerous, risking damage to the heating equipment or even a fire.
Question: fire hazard from damaged fire bricks in Arco Boiler
(Dec 15, 2012) Isaac said:
Need help with my Arco - ideal water boiler
Watch out: Turn off, and Do not run the boiler. a Heatinbg boiler with a collapsed combustion chamber is unsafe.
Call your heating service company. They can replace, rebuild, or reline the fire box.
Question: short cycling heating system diagnosis
5/15/2014 Susan said:
Furnace -Carrier Weathermaker 8000 all works fine.Tech came out for a checkup. I declined the AIC special and pressure switch (both bad he stated) bc all furnace works fine. All still works just fine, but every 5-7 minutes now, 24 hrs. a day, an intermittent. mechanical sound for about 5 seconds clicks on 2-3x in that period and then stops.
What is that sound? Is it happening bc I did not get the AIC and pressure switch? Hope to find out exactly what is the sound? Sorry for the limited info. just want to find out and stop it. Trying to get the company to come back out and put in to parts and hopefully, identify the sound and correct it. Any thoughts? Thanks.
With no data about your system other than your message I can't diagnose the issue accurately, but there seems to be a contradiction between saying the system works fine but it is not working normally and is cycling every 5-7 minutes.
Anderson Instrument Corporation (AIC) produces a line of HVACR pressure control switches and gauges. If the pressure switch on your system is faulty that *could* explain the symptom you describe. Below I give contact information for AIC who produces the control that you ask about.
Other reports of the Carrier Weathermaker 8000 units (you don't give your model but this note is for the Carrier Weathermaker 8000 Model 58WAV090-LC) that are short cycling may display an error code No. 34 or No. 14 or both, indicating a problem with the furnace's ignition system. The system may eventually shut down on safety with Code #34.
Ignition problems are often traced to a mis-located flame sensor, a failed thermocouple, or even dirt (or in a few cases I've seen spider nests) on the sensor assembly.
Watch out: if you see sooting conditions on gas fired equipment the unit is unsafe and should be shut down while you wait for professional service. Sooting gas fired appliances may be producing dangerous, even fatal levels of carbon monoxide.
Other problems can cause a furnace to shut down under control of its temperature limit switch, such as a dirty air filter or dirt-blocked cooling coil in a combination heating/cooling unit. Obstruction of air flow through the heating plenum or het exchanger can cause the system to heat up and shut down before the thermostat is satisfied.
You can detect this condition on furnaces or on systems that provide both heating and cooling and that short cycle in heating mode on units that use a fan limit switch by noting that the switch indicator dial is rotating to the HI LIMIT temperature shutoff during system operation. See FAN LIMIT SWITCH & FAN LIMIT SWITCH TROUBLESHOOTING.
If you do not have the installation and operation manual for your furnace, you can also look for error code signals and their decoding information on data tags right on your Weathermaker 8000 unit.
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.
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