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AIR CONDITIONING & HEAT PUMP SYSTEMS
BACKDRAFTING HEATING EQUIPMENT
BACKUP HEAT for HEAT PUMPS
BANGING HEATING PIPES RADIATORS
BLOWER FAN OPERATION & TESTING
BOOKSTORE - InspectAPedia
BTU USAGE MONITORS
CARBON MONOXIDE - CO
CIRCULATOR PUMPS & RELAYS
DIAGNOSTIC GUIDES A/C / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DRAFT REGULATORS, DAMPERS, BOOSTERS
DUCT SYSTEM & DUCT DEFECTS
ELECTRIC MOTOR DIAGNOSTIC GUIDE
FAN, AIR HANDLER BLOWER UNIT
FLOODED HEATING EQUIPMENT REPAIR
FLUE SIZE SPECIFICATIONS
GAS BURNER Flame & Noise Defects
GAS PIPING, VALVES, CONTROLS
GEOTHERMAL HEATING SYSTEMS
HEAT PUMPS, DIAGNOSIS, REPAIR
HEATING COST SAVINGS METHODS
HEATING OIL PIPING TROUBLES
HEATING OIL TANKS
HEATING SYSTEM NOISES
HEATING SYSTEM TYPES
GAS LP & NATURAL GAS SAFETY HAZARDS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
MOTOR OVERLOAD RESET SWITCH
NOISE, HEATING SYSTEMS
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FILL PIPE LEAKS
OIL SPILL CLEANUP / PREVENTION
PLASTIC Plexvent / Ultravent RECALL
PUFFBACKS, OIL BURNER
RELIEF VALVE LEAKS
Reset Switch - Heater Primary Control
RESET SWITCH - ELECTRIC MOTOR
Reset Switch - Stack Relays
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOOT on OIL FIRED HEATING EQUIPMENT
STEAM HEATING SYSTEMS
THERMOSTATS, HEATING / COOLING
VIDEO GUIDES: Heating System Videos
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
ZONE VALVES, HEATING
Residential heating boiler inspection, installation, diagnosis, &repairs: we describe how to inspect & troubleshoot all types of residential heating systems and we describe just about every common heating system defect or operating problem.
The articles listed on the left side of this heating boiler home page describe the components of a home heating system, how to find the rated heating capacity of an heating system by examining various data tags and components, how to recognize common heating system operating or safety defects, and how to save money on home heating costs. We include product safety recall and other heating system hazards. The limitations of visual inspection of heating systems are described.
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Warm Air Heating Systems - Furnaces: If the heat in your building is provided by warm air that flows out of ceiling, wall, or floor air supply registers into the occupied space, or if your heating system uses a water-to-air heating system then the air which warms the living space is probably being delivered through large or small diameter ducts, registers, air filters, and a furnace blower, and the air is being heated by a gas, oil, or electric furnace, or perhaps by a heat pump or a geothermal system.
Hot Water or Steam Heating Systems - Boilers: If the heat in your building is provided by warm or hot metal radiators, heating baseboards containing finned copper tubing, or wall convectors that look like a radiator but contain finned copper tubing, or if heat is provided by flexible rubber, plastic, or metal tubing run in building floors or ceilings, then the warm or hot water circulating in those devices is probably being delivered by piping circulating water heated by a heating boiler, or possibly by a steam boiler or a heat pump or geothermal system.
See BOILERS, HEATING
What's the difference between a heating boiler and a furnace?
In general, a "heating boiler" heats the building using hot water. A "furnace" heats a building using hot air or "warm air". Don't confuse the two since
their means of making and distributing heat, their controls, and their equipment are mostly different. For a detailed guide to inspecting and maintaining warm air heating systems or furnaces,
What's the difference between a hydronic (hot water) boiler and a steam boiler?
A "steam boiler" delivers heat to the occupied space in the form of steam: the boiler literally "boils" water and sends steam rising up through steam riser pipes and through steam radiators in the occupied space.
If your heating radiators have valves which hiss and let air escape as heat is coming on your heat is probably being delivered in pipes which circulate steam from the steam boiler up through radiators in the occupied space.
For a detailed guide to inspecting and maintaining steam heat systems
How is heating boiler efficiency or economy measured? What does boiler AFUE mean?
Each model of heating boiler is assigned an AFUE number. AFUE is an abbreviation for Annual Fuel Utilization Efficiency. In short, the AFUE tells you, for each dollar you spend on energy for heating by gas, oil, or another fuel, just how much of your dollar shows up inside the occupied space of your building as heat.
Details are at AFUE DEFINITION, RATINGS
What are we looking at when we're talking about oil-fired hot water heat? It's helpful to form a simple working definition that helps understand the system. An oil-fired forced hot water or "hydronic" heating system is a collection of components which heats a building by heating and then circulating hot water through heat-radiating devices located in the occupied space.
A "heating boiler" is a steel, copper, or cast iron "box" of hot water, connected to a loop of pipe (and radiators or baseboards) which runs around through the living area. The same physical water stays in the boiler and is circulated by a pump so that heat is delivered to the living area.
Burning oil makes hot gases which are used to heat the water before being exhausted outside. Pumps move fluids through the system. Safety controls of various types are installed at various points protect against a number of potential hazards.
How does a Heating Boiler Work?
We discuss how heating boilers work in step-by-step detail
This approach broadens the scope of the heating system inspection and it may aid in heating system defect recognition or problem diagnosis, for example by observing that a heating boiler is located in a small, air-tight room (possible combustion air problems), or that the furnace is quite close to the oil storage tank.
Below we give the basics of heating system inspection using the physical location "map" of components to assure completeness. See full details of heating system inspection procedures provided
Is Heating by Hot Water Boiler a Good Approach?
The choice of heating system type involves choices of heat distribution (such as by hot water or steam (boilers), or by air (furnaces), or by using electric heat), or by more hybrid methods such as hot water or electric radiant heat in floors or ceilings, or other approaches. There is no single "right answer" or "best" approach since we need to match the type of heat distribution, heat production, heat fuel to climate, construction, site conditions, fuel availability and other factors.
Reader question: 4/16/14 Diane Logsdon (no email) - are we crazy to consider buying a house that uses hot water boiler heat?
COMMENT: I just looked at a home to buy that has hot water boiler heat. Don't know age but owners say they have always had it maintained since he is a plumber. Are we crazy to consider a house with this type of heating system. How energy efficient are they?
Diane I must be totally confused. Why would using a hot water heating system be less efficient than forced warm air? The heat loss rate of the house in which you are interested is the first determinant of heating cost. Look at the home's insulation, age, quality of construction, and for signs of air leakage such as thermal tracking.
Perhaps you meant to ask something else and I just don't get it.
Efficiency of Different Heating Methods
The efficiency of hot water heating systems (boilers, or hydronic heat) varies depending on the age and type of equipment, the fuel source (oil or gas for example), and very importantly, the state of tune of the system. An old clunky slow-speed oil fired hot water boiler that has not been cleaned or tuned-up might chug along reliably at 65 % efficiency.
I could clean and tune the system and get it up to perhaps 75% efficiency - meaning that if we ignore the very important heating efficiency factors of house insulation, heat loss, drafts, how heat is distributed, and if we just look at the boiler itself, 25 cents on the dollar is going up the chimney.
A new high-efficiency oil fired heater might run at the high 80's of efficiency or close to 90%, sending ten cents up the chimney for every dollar spent on fuel.
Those exact same efficiency ranges can be found in forced warm air heating systems (furnaces) and depending on how heat is made, on radiant heat systems.
Electricity is one of the most efficient heat producers once it's at the home, but once we factor in differences in fuel costs, in many areas of the world electricity is one of the more expensive ways to heat a home.
Efficiency and costs of different heating fuel sources are compared
Reader follow-up: people around here say "stay away from a house with a heating boiler"
It is just the idea that it is a boiler. When I tell people this they say stay away from it! I don't think there are many left in our Bloomington-Normal area. I have a friend who had one at her house and she said it was wonderful even heat but everyone who came to the house said that would have to be replaced right away.
She finally sold her house but it was tough. I'm thinking that if we wanted to resale the house later on it could be a problem. It is the age of the house which has been very well maintained over 60 years by one couple and he was a plumber. Thanks for your answer and I think the house is well insulated and of quality construction. I am not sure what air leakage such as thermal tracking means. Diane
Reply: millions of homes heated by hot water (hydronic) heating systems
Gee Diane, there are literally millions of homes heated by hot water. Sometimes when a type of heating system falls into disuse in an area it is because the contractors who knew how to install and service it have retired or died. Indeed for a given community or area of use it can make sense to prefer buying a product (house or car) that many people in that area know how to fix
. In the U.S. in the 1970's it was very easy to find someone who knew how to fix a VW Beetle and very tough to find a mechanic who knew how to repair the triple-throat-Solex carburetors on a Porsche. But for the area you are discussing, I fear you may be hearing from people with strong opinions that, at least in your comments, they have not backed up with information.
Thermal tracking means stains that can tell us something about building heat loss. You can help me out in managing InspectAPedia by telling me why you didn't try our page top or page bottom search function to search for that term to read about it.
Take a look
Should I buy this house?
Finally, having inspected thousands of homes, I've found very few that were in such bad shape that one would think buying the home is a mistake. Once you choose a house because you like the neighborhood and like the house and the price seems reasonable, most repairs, even a new heating system, make up a rather small percentage of the value of the property so in my OPINION are not reasons to refuse to go ahead with the purchase.
The purpose of a home inspection is not to kill the deal nor to tell you to buy or not buy the house, but rather to tell you what to expect to need to repair and in what priority order - to protect against expensive surprises or dangerous conditions.
Continue reading at BOILER CONTROLS & SWITCHES or select a topic from the More Reading links shown below.
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Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: does my Burnham residential boiler require annual service?
Does my Burnham residential boiler need annual service. It worked fine last season. - Dick 9/19/11
Yes, Dick, there is no Santa Claus; your heating boiler needs annual service not only to assure safe, reliable operation, but because without an annual cleaning, particularly for oil fired heating boilers, my experience is that the cost of operating the equipment will be significantly greater - the improvement in operating efficiency of an oil fired heating boiler following annual cleaning and adjustment can be significant - I've seen a 33% reduction in operating cost following cleaning and adjusting a dirty oil fired boiler or furnace.
Question: Boiler trips circuit breaker - intermittent failure of boiler to turn on
I have a 3 year old Peerless WV-DV boiler, 1 zone (thermostat), 2 circulator pumps, no valves, serviced annually. This year when turning thermostat up the boiler refused to come on. The 20 amp circuit breaker had tripped. It wouldn't reset, kept tripping immediately. I turned the power switch off at the boiler, reset the breaker, turned the power back on at boiler, turned thermostat up and boiler came on normally.
I then, over the course of an hour, turned thermostat up and down, each time boiler shut off and came back on normally. Then is got warm here for a few days, didn't use. When it got cold again, same problem, I had to turn off power at boiler, reset breaker, turn power back on at boiler, then boiler works. I also replaced the breaker in case that was a problem. So what is the issue here? Any help would be appreciated. - Scott Moberg 10/14/11
Question: hot water re circulating loop is not maintaining temperature
having a problem with a hot water recirculating loop from boiler to storage tank with tempering valve to building. not able to maintain proper temp. any ideas? - Vivek 10.26/11
Question: how do I figure out the age of my heating boiler or furnace?
Would like to know the age of a National U.S. Radiator boiler, Boiler # 109-5. It is a five section boiler, with Crane forged into the sections. Only can see the two end section numbers, F10900201 and F10900301. Just curious, thanks for any help. - Gary Forbes 11/5/11
Gary, see AGE of HEATERS, BOILERS, FURNACES (article links listed at the "More Reading" links at the bottom of this article ) for tables, charts, and links to books that give means to decode the age of heating and cooling equipment using the model and serial number.
Question: no heat on upper floor, no air bleeder valves
its just the upper floor and i don't have bleeder valves at the base board the expansion tank at the boiler is hard to tell how full it is - Luke 11/10/11
Luke, at AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE we describe a variety of ways to get air out of an air-bound hot water heating system.
Question: books on troubleshooting residential heating boilers
are there any books on troubleshooting residential boilers & how to wire them - Kevin 1/12/12
Kevin, at References, related articles we list a variety of books on heating system installation & troubleshooting; when I was servicing heating systems, in addition to attending trade school for absolutely-required practical knowledge and theory, I found too that quite a few manufacturers gave away free booklets and pamphlets with excellent detail about their equipment. And don't forget to check the installation and service manual for the specific equipment you are examining.
Question: How do you add antifreeze to a boiler? What kind of antifreeze do we use in a boiler? How much do you add?
Don, some help on winterizing a boiler as well as a whole building is at Winterize- Heat Off Procedure.
The basic procedure is to use a pony pump (a transfer pump - see PUMPS, PONY PUMPS) to add antifreeze (buy at your local heating supplier) to the water mix in the boiler until our test gauge shows that we've got enough antifreeze in the system to protect down to at least a bit below the lowest expected temperature.
The service tech uses a pony pump connected to a boiler drain or zone drain valve, typically using a pair of washing machine hoses to form a loop between a boiler drain, a bucked of antifreeze & water mix, and a zone drain.
The pump pushes antifreeze into the system from the bucket; keeping the drain end of the second hose below the level of antifreeze in the bucket avoids introducing air into the system and thus avoids having to bleed that air out.
Complete details about how to add anti-freeze to a hot water heating boiler and system are found
Question: How to diagnose gurgling sound coming from boiler and radiant heat tubing
I have radiated heat at night tub gurgles and boiler makes noise - Jeff 10/8/12
Jeff, gurgling in hot water heating lines is often due to air in the piping. Check for a leak and for an air purging device that is not working.
(Oct 5, 2014) Elizabeth said:
Smoke stains are being left on the bottom of the unit where yu open to light the pilot - I assume that means it needs cleaning inside. Is this something a homeowner can do themselves?
WATCH OUT: if your boiler is gas fired you are describing an unsafe condition that could produce fatal carbon monoxide gas. If that's the fuel you're using I'd shut off the system and ask for inspection and repair by a licensed plumbing and heating contrator.
This is not a homeowner repair job.
(Oct 11, 2014) Regine said:
Moved in a renovated/insulated/new thermal windows home in April Southern Maine. Home has boiler with tankless water heating system+cast iron radiators. Boiler runs well, no problem. Upon maintenance "tankless coil plate was found to be in poor shape, but does not leak" and we noted having use "lots of oil" during summer.
Want to wait until next March to change the boiler. In the meantime we would like to install a separate electric water system and remove the water heating function off the boiler by sealing/welding permanently the tankless coil: is this feasible? would any heating system contractors do this? We have read that it is possible to weld a coil patch plate over rust to save a good boiler, then switch to either indirect tank or standalone unit.
30 Oct 2014 Kory said:
I have Allied Boiler Super Hot SG180, just a month old. Strangely enough it suddenly stopped working, giving Error Code 59; AC voltage out of specification high or low. Boiler gets call for heat, ignites pilot, ignites main burner and then turns off, and proceeds to repeat sequence. How do I solve this mystery?
I have Allied Boiler Super Hot SG180, just a month old. Strangely enough it suddenly stopped working, giving Error Code 59; AC voltage out of specification high or low. Boiler gets call for heat, ignites pilot, ignites main burner and then turns off, and proceeds to repeat sequence. Checking main wiring going into boiler. It reads 80v AC when connected to boiler, yet when disconnected it reads 120v AC. Not sure why power would drop like that? It is 100yr old house renovated in the 1970's but I am unaware of aluminium wiring (as far as I can see anyway). The ground appears to be ok. How do I solve this mystery?
Kory, that sounds like either a true voltage problem - check the actual voltage level and see if you can find out if there are significant voltage variations in your area - OR a control board problem. As the system is brand new I'd expect it to be under warranty and that a service call would be appropriate.
On voltage variations, that's not a feature of old houses but might be a feature of the house wiring, electrical service incoming voltage, or problems in wiring or in an overloaded circuit supplying the boiler.
Do let me know what you find - what you learn will assist others.
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