The Lennox G71P is a (discontinued) variable speed gas furnace made for use in residential settings. It is also known as G71MMP. In 2008, the G71P won the Silver award from the Dealer Design Award Program. It is rated for 95% AFUE and is Energy Star qualified. This furnace may also qualify buyers to a federal tax credit, according to Lennox’s product brochure.
Its technology includes a patented steel primary heat exchanger and stainless steel secondary heat exchanger. It is equipped with a variable-capacity gas valve and Lennox’s Precise Comfort technology, which the company says controls temperature and airflow in small increments for more efficient use of fuel. The G71P can also be used with an electric heat pump. The Lennox company claims the G71P can save a household up to $1000 on utility costs per year.
Lennox and this furnace in entirely unreliable. Installed in 2008 and it has broken down every year including the very first year of install. Numerous blower motors and circuit board have been replaced. Do not buy Lennox.
"Okay until it failed."
This a Lennox g71mpp series, installed about 10 years ago. For the last 5 years the yearly maintenance tech has noticed rust on the primary heat exchanger but wasn’t sure why. This year another tech discovered the problem. The secondary heat exchanger was leaking condensate, dripping down on the primary. The part was covered under warranty but not labor. Replacing it was a 6 hour job and $1,200 labor cost. We bought it for it’s high efficiency which seemed a responsible thing to do but even setting aside that our gas bill savings will never equal $1,200, the energy required to build and ship a replacement heat exchanger makes for an big picture efficiency loss, not gain. Not at all happy with what seems shoddy design, materials choice or manufacturing process. Shouldn’t we expect it to last more than 10 years or is this the current state of us manufacturing?
I had the Lennox G-71 installed in 2008. This is the best furnace I have owned by far.
Kelowna, BC, Canada
"Lennox equipment poor quality"
We purchased the top of the line Lennox furnace / air handler and have 3 of them in my home. We had to replace one of the coils 2 years after install and just found out another unit has a leaky coil. Compared to all of the neighbors in our community who had Goodman low end units installed at the same time, no one has had this issue. I have subsequently found out Lennox had to settle a class action law suit as this issue is so prevalent. It is due to poor workmanship and low cost metals used in the coil. I would highly recommend not letting your contractor install a Lennox unit in your home.
I’ve had this furnace for 6 or 7 years and my house has never been more comfortable. It runs on low-fire most of the time, but it’s not over- sized. I need the full rate for recovery in the morning, but once the house warms up I never notice the furnace again. It is super quiet and because it runs at a low fan speed, I never feel or hear a whoosh of air coming through the heat registers. It just quietly keeps the temperature in the house right where it’s supposed to be with no overshoot.
Posters in online forums have generally positive things to say about this furnace, though some have experienced problems. In this forum thread, several posters say that problems with the G71MPP are often due to improper installation, rather than the furnace itself.
Lennox G71P Model Numbers
The G71P is available in different models which vary in efficiency and capacity.
BTUs per Hour
G71P furnaces carry a limited lifetime warranty on heat exchanger parts and a 10 year warranty on all other components.
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