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AGE of WATER HEATERS
ALTERNATIVE HOT WATER SOURCES
ANODES & DIP TUBES on WATER HEATERS
ANTI SCALD VALVES
APPLIANCE EFFICIENCY RATINGS
AQUASTAT CONTROL Functions
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER, HEATER WATER FEEDER
CARBON MONOXIDE - CO
CHECK VALVES, WATER SUPPLY
CLOGGED SUPPLY PIPING
CROSS CONNECTIONS, PLUMBING
DEBRIS in WATER SUPPLY, Water Heater
DRAIN a WATER HEATER TANK
ELECTRIC WATER HEATERS
FLOODED WATER HEATER REPAIR
FREEZE-PROOF A BUILDING
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
HEATING COST SAVINGS METHODS
HOT WATER SUPPLY
HOT WATER IMPROVEMENTS
HOT WATER DELIVERY SPEED UP
HOT WATER EFFICIENCY IMPROVEMENT
HOT WATER PRESSURE EXPANSION RATE
HOT WATER PRESSURE LOSS
HOT WATER PROBLEM DIAGNOSIS
HOT WATER QUANTITY IMPROVEMENT
HYDROGEN SULFIDE GAS
INDIRECT FIRED WATER HEATERS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
NO HEAT - NO HOT WATER: HEATER DIAGNOSIS
NOISE, WATER HEATER
ODORS IN WATER
PIPING IN buildings, Clogs Leaks Types
RELIEF VALVE LEAKS
RELIEF VALVES - Water Heaters
SCALE REMOVAL, WATER HEATERS
SEWER GAS ODORS
SOLAR HOT WATER HEATERS
TANKLESS WATER HEATERS
THERMAL EXPANSION of HOT WATER
THERMOSTATS, WATER HEATER
TIMERS for ELECTRIC WATER HEATERS
WATER HEATER ALTERNATIVES
WATER HEATER ANODES, DIP TUBES
WATER HEATER AIR INLET
WATER HEATER DEBRIS FLUSH
WATER HEATER DRAIN PROCEDURE
WATER HEATER EFFICIENCY
WATER HEATER FLUSH PROCEDURE
WATER HEATER NOISES
WATER HEATER PROBLEM DIAGNOSIS
WATER HEATER PROPERTIES
WATER HEATER SCALE
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER ODORS, CAUSE CURE
WATER PIPES, Clogs Leaks Types
WATER PRESSURE TOO HIGH: DANGERS
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER QUANTITY IMPROVEMENT
WATER SOFTENERS & CONDITIONERS
WINTERIZE A BUILDING
Range Boilers for making domestic hot water: in this article we define range boilers, and we explain the operation of range boilers used for making domestic hot water for washing and bathing. We provide photos and sketches as well as text to help identify the types of tanks found inside old buildings.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
A range boiler is an older type of domestic hot water heater which uses a separate hot water tank which is connected to a heating boiler as well as to domestic hot water piping in the home. Thanks to Carson Dunlop, a Toronto Home Inspection Firm and Home Inspection Educator, for permission to use sketches shown in this article. Below we describe some alternative ways to make hot water, either to replace or to supplement an existing hot water supply system. After knowing what the hot water problem really is, there are steps we can take to get more hot water or to increase hot water pressure.
Water circulates from inside the range boiler tank through a heat-exchanger coil that may be inside the heating boiler or it may be external, such as a Side Arm Coil. Heat inside of the physically separate heating boiler warms water that circulates, usually by gravity (or convection) between the range boiler and the heating boiler.
Modern indirect-fired water heaters use the same principle as the range boiler but add heat controls and a circulator pump, as we discuss in detail at Indirect-fired Water Heaters.
In our photo at page top you can see the old galvanized steel range boiler in the far corner of the basement. A newer (but still quite old) gas fired water heater has been installed in front of our old range boiler.
See WATER HEATERS for details about conventional direct-heated residential hot water systems.
You'll find at least four pipes connected to a range boiler tank, possibly five if the tank uses an overflow line in an attic instead of a pressure relief valve.
Don't do what we did early in our HVAC career: some of those many connections on the range boiler seemed to have no purpose so we eliminated and capped off a pipe that seemed unnecessary. It was a mistake. All four pipes which we describe here are needed:
Range boilers are vertical or horizontal hot water systems whose water is heated by circulating the water from within a water storage tank (the range boiler) through a heat exchanger which is inside or connected to the exterior of a heating boiler. The water in the hot water tank range boiler is heated by circulating its water through the heat exchanger which itself is heated by the water inside or from the heating boiler.
The sketch illustrates how a very early type of coal-fired water heater range boiler worked. As homeowners shifted fuels from coal to oil or gas and installed central heating boilers, often the range boiler water heater was adapted to work with these systems as well, as you can see in the photograph.
As with the indirect-fired boiler described next, range boiler water heating tanks are usually located close to the heating boiler and will have both cold and hot water lines leaving the tank to supply the building with domestic hot water and a loop of piping that runs between the bottom of the hot water tank and a nearby heating boiler. Follow the pipes to see which pipes are performing which function. Our photo shows a silver steel range boiler hiding back in the corner behind the newer (though pretty old) gas fired water heater. (Notice also the efflorescence on the masonry block foundation, where the downspout has been spilling by the house foundation?)
The difference between Range Boiler Water Heaters and Indirect-fired Water Heaters is in the details. The heat exchanger that heats water in the range boiler is in or at the heating boiler. The water in an indirect fired water heater such as the SuperStorTM unit is heated by a finned copper coil located inside the hot water tank. The internal coil is in turn heated by circulating water inside the coil to and from the heating boiler. The range boiler is an old concept in use for about 100 years. Indirect fired water heaters are a modern system and are in current sales and use.
Because you might also encounter other smaller steel tanks connected to hot water heating boilers and found in building basements or attics see EXPANSION TANKS for a guide to these tanks that absorb pressure increases on hot water heating systems.
CONTACT us with comments about this attic tank.
Unless the range boiler is vented to an overflow pipe like the attic tank in our discussion below, range boiler tank should be protected by a pressure/temperature relief valve just as any pressurized tank. If none is installed your range boiler does not meet modern safety standards - it is unsafe, and a relief valve should be installed promptly.
See RELIEF VALVES - Water Heaters for details.
Attic Range Boiler - Photos, Pipes, Insulation, & Measurements Help Identify a Large, Antique, Insulated Steel Tank Found in an Attic
A few weeks ago the grandchildren of the second owners (in the fifties) stopped by the house from out of town to look at their grandparent’s house, which they had many fond memories of, and we invited them in for a tour. They are going to contribute stories and old photos for my project.
Now that I’m starting this history project, I want to try and solve the big mystery of identifying “what the THING in my attic is. Over the years I’ve asked a number of people: plumbers, insulating contractors, etc., but no one knows what it is, or what it was for. It has baffled me for years.
Reply: Clues for Sorting Out Attic Tanks in Older Homes
Watch out: I'm worried that someone may have poured loose fill asbestos around that tank to serve as insulation. If the material is firm and foam-like and pale yellow, and collapses to powder on touch it may be UFFI and not so harmful. But if this is a white, loose, dry powder, watch out - seal it off with plastic until we know what you're dealing with.
Obtain advice from an expert, or in an emergency, clean up a tiny spill with a HEPA vacuum, and don't track this material through the house, or you may create a more costly cleanup job.
UFFI was blown in to building walls during the energy worries of the 1970's oil embargo. Your antique attic tank installation with the paper and pit-saw cut boards (FRAMING MATERIALS, Age, Types) looks much older, probably from the time of original construction of the home back in 1917.
How to Identify Heating Boiler Expansion Tanks in Attics
It looks from the partial exposure as if the tank is in a location where people used to put expansion tanks on hot water heating boilers - instead of a relief valve, if pressure in the system got too high, water would push into the tank and if the tank got too full, water would flow out of a drain into an outdoor location, sometimes even a roof gutter or downspout.
But this is probably something else. Usually an expansion tank has just one inlet pipe that feeds water from the hot water heating system, and for attic-located expansion tanks, an overflow drain line.
What Makes This Old Steel Tank in the Attic Not a Heating Boiler Expansion Tank?
But if your heat is or was steam heat, this isn't an expansion tank.
If the tank is a large one, it's probably not an expansion tank for that reason either.
Because the tank is insulated, it's not likely to be an expansion tank and probably not an attic cistern - people didn't bother to insulate those containers.
And most compelling, as your tank has so many pipes connected to it, we have talked ourselves out of the expansion tank theory entirely.
A hot water tank such as a range boiler would have water coming in from a boiler or supply, water going out to plumbing, possibly heating by gravity or convection. More pipes and connections, a least five for an attic tank:
Also see Plumbing Connections for a Range Boiler above.
Control valves may have provided for manual filling or draining of the tank. One might try arguing that the insulation was to avoid freezing, but that wouldn't explain why you saw no insulation on the pipes connected to the tank - or was it drained in winter and the system left dry? If the tank was intended to be drained at times, for service or freeze protection, that little hose and drain pan may have been there to permit leaving the drain line open and to catch the last few drips of water from inside the tank after it was drained through its drain line (over by the chimney perhaps).
Guessing at An Attic-Mounted Range Boiler Tank
A reasonable guess considering size, location, and insulation is that the tank was for storing hot water from a boiler for example, feeding hot water down into the house by gravity and perhaps heating the water in the tank by natural convection to and from a basement boiler or even a separate water heater that could even have been down in the basement. If you can give me tank dimensions (and don't have an asbestos problem) that'd be helpful.
We need to look more closely at where piping comes and goes.
Watch out: if the covering boards were removed (DONT MESS before we know the asbestos question) you'd find hat those four pipes are connected to different heights on the tank.
It's unusual in my experience to put a range boiler in an attic, so remote from the heating boiler, but someone may have done so thinking that they would get better hot water delivery pressure in the home.
And I'd like to know the full measurements of the tank or if you leave it boxed in pending the asbestos question, just the dimensions of the wooden framed box would help.
Keep me posted on the asbestos worry and about to where you can trace piping - that asbestos question is TOP Priority.
Frequently Asked Questions (FAQs)
Questions & answers or comments about installing, using, & repairing range boilers used for hot water supply in buildings.
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Technical Reviewers & References
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