What are the Best High, Low, & DIFF Settings on a Heating Boiler Aquastat?

How to set the HI LO and DIFF on a heating boiler control on an Aquastat
- What Settings To Use on a Heating Boiler Aquastat Combination Control
- Guide to Setting the HI Limit on a Honeywell R8182D heating boiler aquastat & Similar Controls
- Guide to Setting the "LO" Limit on a Honeywell R8182D heating boiler aquastat & Similar Controls
- Guide to Setting the "DIFF" (differential) on a Honeywell R8182D heating boiler aquastat & Similar Controls
- How to save money by setting the Honeywell R8182D and similar controls optimally; How to set the aquastat if heating with a woodstove.
- Guide to the functions of a typical heating boiler combination control aquastat like the Honeywell R8182D, the Honeywell L8124A, and the Honeywell L8151A. Guide to the Honeywell 6006 Single Function Boiler Limit Control
Questions & Answers about the best settings for aquastat controls on heating boilers
References

Click to Show or Hide Related Topics

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Here we explain how to choose the best settings for a heating boiler aquastat - the combination control that sets boiler temperature and may also control hot water production via a tankless coil on the heating boiler. We also give advice on how to set the aquastat controls if heating with a woodstove.

What Settings To Use on a Heating Boiler Aquastat Combination Control

After explaining the Hi, Lo, and Diff controls we review the newer universal replacement aquastat from Honeywell, the L7224U Universal Aquastat, followed by a discussion of the simpler single-limit control switches.

At AQUASTAT CONTROL Functions we explain how aquastats work, defining the functions and dials of the aquastat HI LO and DIFF control along with the reset button often found on these heating boiler controls.

This website answers most questions about Heating System Boiler Controls on central heating systems to aid in troubleshooting, inspection, diagnosis, and repairs. The photo above shows a the "HIGH" or "HI" setting on a Honeywell R8124A combination heating control, also called an "aquastat". Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.

The internal view of the Honeywell R8182D (left) can be found along with additional details about this control in the Honeywell R8182D,H Combination Protectorelay™ Primary Control and Aquastat® Controller Installation Instructions (link to copy below at References).

Following wiring details in the instruction manual, the R8182D,H can replace other aquastat controls such as the Tradeline R8182B, R8182E, R8182F, R8182H, R8182J, or White Rogers 6C92. A newer combination control from Honeywell, the Honeywell L7224U Oil Electronic Aquastat Controller can replace more than 40 older hydronic controls.

Lots of people, even some service technicians are confused about the actual function of combination controls and aquastats like the Honeywell R8182D. Some don't know how to set the "HI", "LO" and "DIFF" dials on a combination control.

Rule of Thumb for Setting HI LO DIFF on an Aquastat

Or more commonly, we were taught to just use a "rule of thumb" which set the "HI" to 180 degF and the "LO" to 160 degF. The DIFF is often set to 10, or is just set randomly.

These were "Safe" settings for this control, and it's in with similar settings on millions of heating boilers. But with a little thought, we can adjust these HI LO DIFF settings and thus set the heating aquastat control so as to save a bit more on heating cost, and/or we can set the control to give us a bit more hot water where a tankless coil is installed.

Guide to Best Settings for the HI Limit on a Honeywell R8182D Heating Boiler Aquastat & Similar Controls:

The "HI" on a combination heating control like this aquastat is usually set by the heating service technician to a spot between 180 degF and 200 degF. Or the "rule of thumb" fellows just park it at about "180" degF as you can see in our photo.

Setting the HI: save money on heating costs by running the boiler at a higher temperature

Generally a heating boiler is more efficient if we operate it at a higher temperature.

The thermal conductivity of heating water inside of finned copper tubing baseboards or through radiator surfaces is exponentially greater at higher temperatures.

In other words, hotter water actually transfers heat into the occupied space more efficiently than cooler water.

Since this is not lab-grade equipment these settings are not precisely accurate. For this reason we like to set our HI limit at around 200 degF.

We let the boiler run through a few heating cycles, watching the temperature and pressure gauges on the boiler to see what temperature we're actually reaching. And we watch the boiler relief valve to be sure we're not causing leakage there.

Watch out: Setting the "HI" too high on the aquastat can result in over-temperature in the heating boiler and can result in dumping water and temperature and pressure at the relief valve. If your TP valve was not leaking before and it begins to drip when you set up the HI to 200 F, step the HI back to 195 and try that setting. If your TP valve is leaking at 195 or less it's likely that you need a heating service call - something's probably wrong with the relief valve, with system operating pressures, or with the controls.

Guide to Best Settings for the "LO" Limit on a Honeywell R8182D Heating Boiler Aquastat & Similar Controls:

In our photo at left you'll see where the heating service tech left this "LO" limit control after cleaning and tuning the heating boiler.

The "LO" is set at least 20 deg F. below the "HI" limit on a combination control. If we set the "LO" any closer top "HI" it is possible that the control, trying to give priority to making domestic hot water for someone in the shower, will simply lock out the circulator pump entirely - the heating circulator will never run. Your heat will work, but slowly, and more expensively, as we explain below at Circulator Lockout.

We like to keep our LO set at 20 F below the HI. That keeps the LO temperature operating range as high as possible in the boiler and that in turn gives us the most heat stored in the boiler for making hot water through the tankless coil.

Avoiding Circulator Lockout - Set LO 20 or more below HI

What happens if you "cross the controls" and set "LO" above "HI" or if you set "LO" too close to "HI"? The circulator will not run.

Watch out: don't set the LO above or higher than the HI temperature limit. If you make that mistake, you will lock out the circulator pump and your heating system will not work properly. We call this "lock out" - the circulator will be locked out of running on a call for heat. Others call this LO higher than HI "crossed controls".

We've inspected homes at which the owner, for decades, observed that the heat in the building was very slow to come up in response to the thermostat. The problem was that the LO was set close to or even above the HI - the circulator pump never ran and hot heating water circulated but only very slowly by convection.

We found a home where the owner had set the "HI" to 120 and the "LO" to 180. Luckily for them, because their flow-control valve was either absent or not working, their home would indeed receive heat - but very slowly: their circulator pump had never run. On seeing this setting we asked the owner about it. "Well you know", he said, "we have noticed that the house was always very slow to heat up in winter." Thanks to reader L. Clark for pointing out that we had inconsistent language in this explanation. It's been fixed, and fixed again thanks to reader Damian for suggesting further clarifications.

Guide to Setting the "DIFF" (differential) on a Honeywell R8182D heating boiler aquastat & Similar Controls:

Where a tankless coil is installed on a heating boiler to make domestic hot water (for washing and bathing) we prefer to set the differential (DIFF) to its highest number (usually 25 degrees).

Our photo (left) shows the DIFF adjustment on a Honeywell aquastat. This DIFF is set to its lowest value: 10 degF.

At the setting shown, if LO were set to 120, when the burner is re-heating the boiler water and water temperature rises to 130 F the burner will turn off and the heating circulator pumps will be allowed to turn on (and they will actually turn on if the room thermostat is calling for heat).

If you re-set the DIFF dial up to its maximum of 25 and LO remained at 120 F, then when the burner is re-heating the boiler water and water temperature rises to 145 F the burner will turn off and the heating circulator pumps will be allowed to turn on (and they will actually turn on if the room thermostat is calling for heat).

In short, DIFF = 25 should give you hotter boiler temperature and thus more domestic hot water than DIFF = 10.

Keep in mind that the LO and DIFF control settings only make sense if the heating boiler has a tankless coil installed to make domestic hot water (for washing and bathing). If your heating system does NOT include a tankless coil, the LO and DIFF are keeping heat in the boiler for a tankless coil that is not present and you could consider either disabling this circuit entirely or setting both LO and DIFF to their lowest settings. Details are at Disabling the LO and DIFF settings

Watch out: be sure that a mixing valve or anti-scalding valve is installed to avoid hot water burns as well as to make effective use of this higher boiler temperature.

For details about the HI, LO, and DIFF actually work, refer to our text and to the yellow-colored area in our colored version of the HI LO functions explained in detail at AQUASTAT CONTROL Functions in that article's section More about How the HI and LO Limit Controls Function on an Aquastat above. From that article, this quote helps explain what the DIFF control is doing on an aquastat:

When boiler temperature is rising: on an aquastat control, the "DIFF" or differential control dial specifies the amount above the LO or "Low Limit" to which boiler temperature must rise before the burner will turn off and the circulator will be allowed to run.

It's not hard to understand why heating service techs and homeowners are confused about LO and DIFF settings on a heating boiler, but Honeywell got it right: if we are making hot water with a tankless coil, by locking out the circulator at lower boiler temperatures, the LO and DIFF make sure that heating priority is given to the woman in the shower, not to the building radiators.

Guide to Disabling the LO and DIFF settings on a Boiler that Does Not Use a Tankless Coil for Domestic Hot Water

If a tankless coil is not installed on a boiler where this combination aquastat control is installed, this combination control may still be in use. And that's not always desirable. It depends.

In this case, the "LO" has almost no use whatsoever and, if you read the instructions provided by the control manufacturer you'll probably see that the manufacturer calls for the "LO" to be electrically disconnected entirely - it's simply a matter of removing a jumper wire (usually the blue wire pointed-to by our pen, next to the DIFF control. Next to each control wire push-in connector is a small rectangular slot.

WITH ELECTRICAL POWER OFF pressing a tiny screwdriver or even a small nail into the slot will release spring pressure so that the wire can be pulled out of its connector. As you can see (photo at left), we placed a small twist-on connector electrical cap ("wire nut") onto the un-used blue wire tip after the wire was disconnected.

Short heating boiler "on" cycles? If you do not disconnect the "LO" limit switch on a combination control on a heating boiler where no tankless coil is installed, during the summer you may wonder why once in a while you hear your heating boiler running.

Why is the heating boiler mysteriously turning itself on and off? Now you can solve this mystery.

Incidentally another cause of oil burner short-cycling on might be poor contact between the boiler temperature sensing bulb (part of this control) and the well into the boiler water into which the sensor is placed. Or a defective sensor bulb might also cause this problem, in which case the control along with its temperature sensor will need to be replaced.

Cast iron boiler leaks? In a few cases, certain cast iron boilers may cool off and begin to leak between their cast iron sections during the summer. This may be a reason to keep the "LO" wired and active on just these heating boilers.

Questions and Answers on Setting the Aquastat Control Temperatures and Differential

Question: What's the DIFF? Here is a DIFF twist question for setting the Differential on an Aquastat when Running a Woodstove

I've read all the informative articles about adjusting the aquastat control on a heating boiler, however I have a situation that was not addressed.

I've just installed a woodstove in my house. I am running it 24/7 because of the price of oil. I have been turning my boiler off for 23 hours each day and just turning it on to clean dinner dishes and take showers - for one hour. Is this okay? To shut the boiler down for 23 hours each day? The temp in the basement is about 46 degrees.

I have 4 zones on my hydronic system and a tankless coil inside the Utica Starfire II oil boiler. 82% efficiency. None of the 4 heating zones need to call for heat when the woodstove is operating.

Should I leave the boiler off as I have been the last few weeks? OR, should I turn the boiler on 24/7 and leave the LO set at 120 (lowest point) and set the high at 180-160-140 ? What should the DIFF be set at? We only need hot water about one hour each day - from about 9pm to 10pm. - Damian

Reply: Watch out for Freezing Pipes and Boiler Leaks

At similar woodstove-heated homes where a hydronic boiler heating system was installed, we found that the woodstove could keep the room containing the heating thermostat warm enough that the boiler would virtually never run. And everyone felt smug about saving on heating cost. But you're right that there are a few things to worry about besides having to keep the boiler hot for the tankless coil used to produce domestic hot water for washing and bathing.

Keeping the Tankless Coil Hot:

For readers not familiar with the HI LO and DIFF settings on aquastats, see AQUASTAT CONTROL Functions as well as this article.

Your note indicates that you are using a tankless coil for producing domestic hot water. You could leave the diff set quite low, say down to 120, but the problem is likely to be that you won't have much hot water when you do need it, unless your boiler were an older, physically larger or cast iron unit that had plenty of thermal mass. So one option would be to leave the Hi and Lo set at their normal positions, say HI at 180 or even 200, and the LO at least 20 degrees below the HI, at 160 or 180 respectively.

The HI will actually be irrelevant in your as you're never calling for heat - just leave it alone so that if you're away from home and the boiler needs to kick in to prevent pipe freezing, the settings will be at their normal position.

On modern heating boilers we like to keep the DIFF set to its lowest setting because that turns on the boiler soonest when you are running out of hot water and helps prevent having to get the soap out of your hair using cold water.

Our OPINION is that the standby losses for the boiler are not bad with this setup because your oil or gas burner is not having to heat up all of that water that's in the heating distribution piping (or baseboards or radiators), it's just keeping water right there in the boiler hot.

If your hot water usage volume is very small and/or if you don't have a mixing valve to avoid scalding, you can set the LO to a still lower number if you prefer.

Tradeoffs on Turning Off the Boiler to Save Money

Turning off the heating boiler in order to save money during most of the day when you are not using hot water, sounds appealing. A much debated question is just where is the break-even point between the standby losses from keeping the boiler warm, versus the extra fuel you have to burn to heat up an ice cold boiler when you need hot water from the tankless coil.

Our OPINION is that the cost to heat up a very cold boiler in a basement or crawl area just to make hot water is worse if it's a larger boiler or a cast iron unit that will have more (cold) thermal mass. If it's a modern, physically smaller steel boiler, your cost to heat it up from cold will be less - but then your tankless coil is going to suck that heat out quickly when you're running hot water through the tankless coil regardless.

An exactly correct answer to this question requires either some theoretical calculations for your particular boiler, burner, and the gph or BTUh rate of the burner along with the thermal mass of the boiler. Easier might be to keep an eye on the total boiler run time under the two circumstances: left on and an occasional intermittent burn cycle versus left off and a longer heat-up cycle. It's slightly more complex: heating up an ice cold boiler may force the burner to run at less than optimum efficiency for a longer part of its burn cycle than otherwise.

Warnings about Turning off the Boiler Completely

Leaky Cold Boiler: Some models of older cast iron boilers develop leaks between cast iron sections if the boiler is not kept hot. That problem can lead to costly boiler repairs or even damage leading to boiler replacement.
Leaky Valves: Sometimes we also find that a valve, perhaps the TP Valve, will start to drip on an ice cold boiler - just occasionally, and it should never happen, but we've seen it.
Frozen heating zone piping: especially in older homes that might have a drafty corner somewhere close to a heating water distribution pipe, we found that causing the hot water heat to run too infrequently or not at all during very cold weather led to a frozen, burst heating pipe.

Except in extreme cases you could leave the boiler off and leave the circulators running 24/7 to avoid this risk. That will distribute enough heat and keep water moving in the pipes enough to reduce the chances of a freeze-up of the heating piping. In Canada, unlike in the U.S., the customary hydronic heating system setup works this way: the circulators always run and the thermostat just turns the boiler on or off.
Frozen House: And of course leaving home unexpectedly can lead someone to forget to turn the heat back on, risking frozen pipes and very expensive damage that would have been avoided if the boiler had been left on. Our solution to this worry is to set the room thermostat to a low temperature, maybe 40 degF as insurance against a house freeze-up. See FREEZE-PROOF A BUILDING if this is a worry.

Bottom line on Woodstoves and Hydronic Heating

Do some experimenting with how long it takes to heat up your boiler if you leave it shut down entirely, and watch out for frozen pipes.
Find and insulate or seal any drafts you can find, especially drafts blowing icy wind on building heating or water piping.
Watch out for leaks.

Frequently Asked Questions (FAQs)

...

Ask a Question or Search InspectApedia

Questions & answers or comments about the best settings for aquastat controls on heating boilers

Ask a Question or Enter Search Terms in the InspectApedia search box just below.

Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. (416) 964-9415 1-800-268-7070 info@carsondunlop.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:
- Commercial Building Inspection Courses - protocol ASTM Standard E 2018-08 for Property Condition Assessments
- Home Inspection Education Courses including home study & live classes at eleven colleges & universities.
- 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.
Thanks to Bottini Fuel service manager Ron Thomas for discussing aquastat functions, low limit controls, oil burner short cycling causes, and boiler maintenance, reliability, and service contracts 4/13/2010. Bottini Fuel is a residential and commercial heating oil distributor and oil heat service company in Wappingers Falls, NY and with offices in other New York locations. Bottini Fuel, 2785 W Main St, Wappingers Falls NY, 12590-1576 (845) 297-5580 more contact information for Bottini Fuel
Thanks to reader L. Clark for pointing out that we had made an error in our HI and LO setting language - October 2010
Thanks to reader Damian for clarifying the LO and DIFF setting functions - March 2011
We provide links just below to several aquastat installation, setting, and adjustment documents in response to reader requests and comments that people sometimes have difficulty finding this information. But readers looking for specific aquastat control information should always first try the control manufacturer.
Armstrong 24-hour time and aquastat control accessory: provides on/off pump control according to preset operating times, designed only for use with specified Armstrong Astro series wet roto circulators installed in indoor hot water re circulation applications. Typical timer applications will cycle the pump at preset times, allowing the user to select operation of the circulating pump during high peak usage periods in order to decrease the delivery time to outlet fixtures and reduce wasted water, also available at www.honeywell.com
Honeywell Corporation, control installation guides for Honeywell aquastats and other heating and cooling controls: see http://customer.honeywell.com
Honeywell L4008E Aquastat high limit,manual reset, aquastat controller instructions
Honeywell L4041A,C Pool Heater Aquastat Controller Instructions, also available at www.honeywell.com
Honeywell L4006, Manual Reset Strap-On Aquastat (high limit control, 100 to 240 degF) [we consider strap on controls less accurate and reliable than immersion type sensor controls; these were commonly found on older heating boilers including the GE series downfired boilers]
Honeywell L4026B Aquastat control instructions (contact Honeywell Corporation) Here is some basic description of the Honeywell L4026B control, also available at www.honeywell.com
Honeywell L4029 Reset Limit Control, also available at www.honeywell.com
Honeywell L4103A,B,C Combination Aquastat and High Limit Controller Instructions, also available at www.honeywell.com
Honeywell L6006A Aquastat Controller installation instructions, also available at www.honeywell.com
Honeywell L6006 and L6007 Aquastat Controllers, installation instructions for the trained service technician, these controls combine low or high limit and circulator control, with or without an immersion well depending on the control model A,B, C etc., also available at www.honeywell.com
Honeywell L6191 Dual aquastat immersion thermostat, also available at www.honeywell.com
Honeywell L7224 Aquastat Controller, oil electronic controls allowing high limit, high limit differential, low limit, and separate low limit differential settings - set to the specifications of your oil heating equipment manufacturer - 69-1957-1 L7224 Series controls, also available at www.honeywell.com
Honeywell L7224U Oil Electronic Aquastat Controller - 69-1720-2 series instructions. These newer aquastat controllers are often used to replace the older Honeywell L8124A series that was and remains widely used, also available at www.honeywell.com.
Honeywell L8124A,B,C,E,G,LO,M Aquastat Relays immersion type controllers for forced hydronic heating systems that include domestic hot water service (such as a tankless coil), also available at www.honeywell.com
Honeywell R8182D,H Combination Protectorelay™ Primary Control and Aquastat® Controller Installation Instructions combination protectorelay Primary Control installation and operations manual, also available at www.honeywell.com

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.

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.

Building inspection education & report writing systems from Carson, Dunlop & Associates Ltd

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.
Domestic and Commercial Oil Burners, Charles H. Burkhardt, McGraw Hill Book Company, New York 3rd Ed 1969.
National Fuel Gas Code (Z223.1) $16.00 and National Fuel Gas Code Handbook (Z223.2) $47.00 American Gas Association (A.G.A.), 1515 Wilson Boulevard, Arlington, VA 22209 also available from National Fire Protection Association, Batterymarch Park, Quincy, MA 02269. Fundamentals of Gas Appliance Venting and Ventilation, 1985, American Gas Association Laboratories, Engineering Services Department. American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209. Catalog #XHO585. Reprinted 1989.
The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
"Residential Steam Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
"Residential Hydronic (circulating hot water) Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
"Warm Air Heating Systems". Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
Heating, Ventilating, and Air Conditioning Volume I, Heating Fundamentals,
Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
Installation Guide for Residential Hydronic Heating Systems
Installation Guide #200, The Hydronics Institute, 35 Russo Place, Berkeley Heights, NJ 07922
The ABC's of Retention Head Oil Burners, National Association of Oil Heat Service Managers, TM 115, National Old Timers' Association of the Energy Industry, PO Box 168, Mineola, NY 11501. (Excellent tips on spotting problems on oil-fired heating equipment. Booklet.)
...


	InspectAPedia^®	InspectAPedia
	Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair	Ask a Question or Search InspectAPedia

Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair

Ask a Question or Search InspectAPedia