Lennox Conservator Boilers | FurnaceCompare®

Lennox Conservator Boiler Overview

The Lennox Conservator boiler is a gas-fired induced draft water boiler. Six sizes, all with product numbers beginning with GWB8, are available in a range of efficiency ratings from 82.0 to 84.4 percent AFUE. This boiler is designed with flexibility in mind, as it can be configured to accommodate several installation needs, including side wall venting. It also can function with either natural or LP gas.

The Conservator has an electronic ignition to minimize gas consumption. The induced draft combustion allows for efficient heat transfer as the inducer fan optimizes the flue gas rate of travel through the boiler. The unit’s efficiency is further aided by the thick fiberglass insulation within its jacket; this insulation is designed to reduce fuel consumption and minimize heat loss during the off-cycle.

This line of Lennox boilers is manufactured with a baked-on enamel finish, cast-iron heat exchangers and corrosion-resistant titanium burners. Additionally, it comes with safety features such as a pressure switch that ensures clear flue for venting. Factory testing is performed for each unit for quality assurance for consumers.

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Consumer Reviews of Lennox Conservator


  • Very Satisfied
  • Somewhat Satisfied
  • Neutral
  • Somewhat Unsatisfied
  • Very Unsatisfied
  • #5 of 6 Lennox Boiler
  • 25% of customers recommended

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Lennox Conservator Boiler Reviews

"Emit potentially deadly levels of CO when HX fails"

1.0 rating
Very Unsatisfied

The heat exchanger, blower motor, control board, and other major parts have all failed at least once on my unit. When the heat exchanger fails it emits potentially deadly levels of co. Gas Company shut off my system the first time due to levels above 10,000 ppm. The second time the technician's meter spiked out at 1,200 ppm and the level was still climbing. Don't be fooled by the warranty. It only covers the replacement parts, where labor is the big expense. Replacing poor quality parts with other poor quality parts just means you get to pay for the same failure multiple times. Customer support is of no help.



"Lennox #2 Oil Home Furnace"

3.0 rating

If you have #2 home heating oil, this oil burner does the job. We have forced hot water and the house heats up fast. Always plenty of hot water for showers, dishes, etc. Runs pretty clean, we've had it for 11 years and no problems to report with it. We recently had our chimney swept and the sweeper was surprised that it hadn't been longer, the chimney was really clean.

P Morin

Manchester, NH

"Excellent Choice"

5.0 rating
Very Satisfied

I purchased a Lennox cowb2 boiler unit about three or four years ago. It is a very good boiler unit. I am completely satisfied with my purchase. I have not seen as much of a reduction in my utility bill as I would have liked to, but I did see a reduction. The Lennox cowb2 boiler unit is very quiet when running, that is a very nice positive attribute. I think with a few upgrades to my house my energy bill will be right down there where I expected it to be. I have qualified technician come out once a year to check out the system and make sure nothing is wrong or going bad with the system. They have never found a problem. Overall my Lennox cowb2 boiler unit is a great system that I would recommend to anyone that is looking to replace their old worn out system.

Panama City Beach, FL

"Stay away from Lennox"

1.0 rating
Very Unsatisfied

Started with Lennox Complete Heat in 1996. Two years later totally replaced with new Complete Heat because of so many problems with first unit. Four years later another completely new unit after prior unit failed. This unit then failed in 2004 and we "upgraded" to a GWB9 which lasted less than 5 years before the heat exchanger developed a leak. This heat exchanger lasted less than 2 years before it also developed a leak. Just paid over $2,000 for replacement of the heat exchanger and many parts. Now unit is backfiring (scary) and short cycling. Local company rep ignores my emails and calls asking which service company can actually fix his product. Cannot reach humans at company Customer Relations number. Terrible products from terrible company.

A. Morin

Northborough, MA

Other Conservator Reviews

Other online discussion boards include multiple instances in which this unit’s electronic igniters fail to light. In most instances, these Conservator boilers are about 10-years old. In the instance of one homeowner on handymanwire.com, the igniters were replaced but the problem continues. After this additional failure, a contractor on this forum recommends that the sensors be replaced; according to this expert, they can �become fouled� in only a few months time. Other online threads describe problems with the fan/limit control sticking, which can result in the blower running for too long. This issue can reportedly be fixed by adjusting the unit’s calibration.

Lennox Conservator Model Numbers

The Conservator is available in different models which vary in efficiency and capacity.

Model Number AFUE BTUs per Hour
GWB9075IH 90 75000
GWB9100IH 90 100000

Conservator Warranty

The Lennox Conservator comes with a 20-year limited warranty on the heat exchanger with non-prorated coverage. Other parts are covered by a 1-year limited warranty.

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