Air Force Heating Blog

The Complete High-Efficiency Furnace Buying Guide

Many people assume that installing a new furnace is like purchasing a new fridge, stove or washer and dryer. But in reality, a new heater requires much more work, and you should be very picky about who you select to perform the task.

Purchasing a new furnace can be daunting and frustrating, but it doesn’t have to be! We’ve put together all the key elements to help you make an informed and educated choice.

7 Steps to installing a new high-efficiency furnace. What to avoid.

A quality installation averages six to eight hours with two technicians.

Step #1 Remove and dispose of the old furnace.

You want a reputable contractor with insurance and guarantees. Walls and floors are commonly damaged when dealing with mediocre installers. WCB is important too! Carrying heavy objects, walking on ice and snow, climbing onto roofs and handling sharp materials are all part of your installation.

Step #2 Core holes in the side of the home for the intake and exhaust.

Mediocre installers can make a mess of your home. Coring holes in the wrong location/position & damaging water and electrical lines happen in our trade more often than you want to know. Protect yourself and your home.

Step #3 Resize existing chimney to a smaller diameter for the hot water tank.

Some chimneys have offsets or were installed improperly from day 1. Be prepared for possible access holes to be cut in walls or ceilings if not caught during the initial consultation. Even worse, you could be forced to purchase more expensive equipment once the installation has begun.

Step #4 Placement of new furnace & base…

Also, install carbon monoxide detectors, basement return air, sheet metal adapter, filter rack, drain, horizontal PVC venting, and the hot water tank venting. Reconnect the gas line, electrical circuit and thermostat control.

No matter what equipment you buy, it’s performance and longevity are affected by the quality of the installation. Understand, the end of the assembly line is your mechanical room. We all hear the stories where people curse the day they installed a new high-efficiency furnace. Upon closer inspection, poor installation(s) and not the equipment itself is to blame.

Step #5 Commissioning the new unit. 

Test fire unit and calibrate the gas pressure and air flow. In most instances, check and adjust all the home supply vents too. 

Don’t be alarmed when the smoke detectors go off, and you smell the weird smell. The furnace is test fired and the oils and chemicals on the heat exchanger getting burned off.

Furnaces require tuning to match your home. Heaters have control boards with dip switches, and they are used to calibrate the unit to your home. If done improperly or left at default, you’re guaranteed a miserable experience. Sadly, this is the case with far too many installations.

Step #6 Complete checklists, client quality assurance walk-through and explain products.

A reputable contractor will perform a walkthrough with you, ensuring you’re satisfied with the installation and explain how your new equipment operates. If your sales rep or estimator doesn’t pay attention to detail or whips in and out of your home like a Tasmanian devil, you can bet it’s company culture and the same will be for the installers. Be aware!

Step #7 Collect payment or finalize financing.

Never pay in full upfront. Some companies will require 10%, 25% or even 50% down to secure the day and equipment. If that is the case, as the homeowner I would offer the same terms to the contractor. You should consider holding the equal amount back until seven days after the installation. To ensure your 100% SATISFIED with the quality and products performance.

“What’s good for the goose is good for the gander.”

Final comments.

Newly installed equipment may require tweaking, it’s not uncommon to need your contractor to return within a few days or weeks to adjust a few things (new equipment operates differently than old).

Usually minor issues like balancing airflow to specific rooms, addressing some noisy ductwork or answering a few questions you didn’t ask during the walkthrough.

And lastly, be careful of tailgate warranties! (warranties that only last as long as the tailgate of their truck is still in sight).

High-Efficiency Furnace Models Simplified.

Which one do I choose? Furnace Models.

We provide simple explanations of the “common high-efficiency furnace models” purchased in Calgary and area.

Furnaces have two sections. The upper cabinet houses the heat exchangers, drainage system, inducer motor and gas valve. The lower, the circuit board and blower motor.

When dealing with efficiencies and furnace models, the two key components are the gas value (gas consumption) and the blower motor (electricity).

Single Stage Furnace

These furnaces use 20-40% less gas annually. They are best suited for bungalows, open floor plans, and townhomes. They only have on or off functionality though.

Two Stage Furnace with ECM blower

Annually uses 30% less gas and 33% less electricity than a single stage high-efficiency furnace. Perfect for two-story homes and families that want more out of their heaters. They can heat multiple levels consistently and evenly. They have two stages of output intensity like settings on a hotel desk lamp.

Two Stage Furnace with Variable blower

These models use 30% less gas and 66% less electricity than the single stage furnace. It has an upgraded control board and an additional component added unto the ECM blower.

The unit can run continuously at very low speeds! Perfect for larger two-story homes with problematic hot or cold areas. Also, an excellent solution when air quality concerns need addressing or you are a light sleeper. Same as ECM option but cost even less to operate.

Modulating Furnace with Variable Blower

These units use 8-12% less gas than a two-stage furnace. Designed primarily for large custom homes with zoning. These models offer ultimate comfort in all styles of homes and floor plans. To get the maximum benefits from these furnaces though, they sometimes need to be paired with a costly “communicating” thermostat. They operate like a light dimmer switch. Various outputs of intensity with ease.

How Does A Two-Stage Furnace WORK?

Simply put, a two-stage furnace has three positions or settings for the gas valve, the valve regulates the amount of gas burned by the unit.

When off it’s “closed.”
When the thermostat turns on, the valve goes to “partially open.” (normally 60-65% compacity)
And if the home doesn’t reach your desired temperature in a specific time, the gas valve opens to “fully open” position and gives the max heating capacity.

Not to overcomplicate things but the first stage is called “low fire” & second stage “high fire.” Two-stage furnaces also can jump straight to high fire if you raise the thermostat 3 degrees or more (if your installer sets it up correctly).

When two-stage furnaces are sized, installed and commissioned correctly, they run less often but run longer. That is the #1 reason why they can heat larger bungalows and two-story homes more consistently and evenly.

2 Stage Is Best For Calgary

This model is great for our region. Furnaces are sized to handle the worst-case scenario or the coldest days of the year, these -30 to -40 degrees Celsius days only account for 10% of the yearly runtime. 90% of the annual runtime, your furnace will just be firing on “low fire,” saving on utilities and prolonging the life of your equipment (not working as hard).

Typically, a two-stage furnace is $1000 more than its single counterpart.  The higher cost takes 3-5 years to recoup in utility savings. (depends on the size of the unit and your desired temperature).

How to stop a furnace installation from turning into a 5-day EPISODE!

On numerous occasions, I’ve seen simple furnace installs turn into five-day episodes.

Day #1 Quotes

Most people get three quotes, as they should. On average this takes about 60 minutes per contractor, plus you’re own online research time and energy. Approx. A day.

Day #2 Installation

You select your contractor and commit to an installation date, that generally takes on average eight hours. (Hopefully, they show up or don’t reschedule the morning of, that would add even another day).

Day #3 Inspection

Now you need to book your city inspection, in Calgary and area that takes a day but you have up to 90 days to schedule. The city schedules an eight-hour window and the on the morning of you can inquire if you’re scheduled for a morning or afternoon inspection, narrowing it down to a four-hour window.

Hopefully, you hired a great contractor and the inspection passes with flying colors and high praise from the inspector. OR the City fails the inspection!

Possible Day #4 Failed Inspection

I wasn’t prepared for this. Furnace frustrations.

Now you have to negotiate with the contractor on a suitable time to address the deficiencies. Most instances the contractor will push for a time that best suits their schedule and not yours, either way, lost time and aggravation.

Possible Day #5 Re-inspection

The city needs to return and re-inspect the installation ensuring all deficiencies were corrected. Again is an eight-hour window and reduced to four-hour the morning of the scheduled date.

The Moral of the story.

A reputable contractor dramatically decreases your chance of a failed inspection and saves you from the aggravation of using up valuable holiday time or worst yet, LOSS OF INCOME.

If the city does fail your install (depending on the severity), you begin to question every element about the application and remorse can set in.

I’ve worked for both small and large furnace installation companies and everything in between. You would be surprised how high some company’s call-back or inspection fail rates are.

I’ve seen as high as 80%; this happens more often with larger companies who have to employ junior installers or sub-contractors to meet they’re in fluxed demand during peak seasons. But not limited to only them, some small fly by night contractors are as bad, if not worst.

Furnace Installation & Service Trends You Need To Know.

We’ve noticed a few new trend(s) in our city and it isn’t for the better.

Since the economic downturn, competition is getting fierce to earn your heating or air conditioning business. But what some contractors are doing to cut costs and stay competitive despite increased products cost, overhead or poor management is to get creative with labor costs. 

Here are four new cost-cutting systems employed by some contractors in our city that you may or may not want to endorse.

One-person crews

Running one-person crews is one way to cut down on labor cost. No matter how experienced or great an installer maybe or think they are, working alone drastically increases the risk of sub-par work or worst, personal injury due to fatigue or rushing to complete the project promptly.


More and more companies are opting to keep a skeleton crew for the typical day to day operations but during peak seasons employing subcontractors to handle the increased volume. Allowing for multiple savings, i.e., fewer company vehicles and tools, WCB, insurance premiums, overtime wages, etc.

Subcontractors aren’t necessarily evil, but we do notice a considerable drop in quality due to it. Also, future warranty issues have a big question mark.


Piecework structures are undercutting journeyman wages. Creating two noticeable outcomes; experienced technicians are leaving to work for companies that pay fair hourly compensation, and junior (apprentice) installers are installing on their own, which in turn is sacrificing quality.

The second, in most cases the projects are being rushed because the workers are paid a set amount regardless of the number of hours worked. Not all but most guys abuse this type of system without proper supervision.

Commission based service techs

Commissions instead of hourly wages are compensating service techs. Technicians being paid a percentage portion of the repair bill only! This structure is driving up repair costs; some techs are charging absurd prices or even worst, charging for parts that don’t need replacing.

How Much Does a High-Efficiency Furnace Cost?

The elephant in the room. Furnace Pricing.

The cost is always a key factor when purchasing anything. Here is the breakdown to help you understand the range of pricing on furnaces.

The short version; $3,200 to $6,500 for the equipment, materials, permits, and labor.

Why such a big range?

Furnace efficiency, warranties, brands, equipment add-ons, unit size and install application vary from home to home and then there is the contractor variable to consider.

But here is a ballpark calculator you can use to budget.

With multiple unit replacements, most contractors will give a discount.

Single-stage furnace pricing

1,000 sqft = $3,200 (30-60,000 BTU)

1,050 to 1,600 sqft = $3,800 (70-80,000 BTU)

1,650 to 2,100 sqft = $4,400 (90-100,000 BTU)

2,150 plus sqft = $5,000 (115-135,000 BTU)

Two-stage furnace pricing

1,000 sqft = $4,000 (40-60,000 BTU)

1,050 to 1,600 sqft = $4,500 (70-80,000 BTU)

1,650 to 2,100 sqft = $5,000 (90-100,000 BTU

2,150 plus sqft = $5,800 (115-135,000 BTU)

Modulating furnace pricing 

1,000 sqft = $4,500 (45-60,000 BTU)

1,050 to 1,600 sqft = $5,000 (70-80,000 BTU)

1,650 to 2,100 sqft = $5,600 (90-100,000 BTU)

2,150 plus sqft = $6,300 (115-135,000 BTU)

What is the Best brand?

Furnace brands explained.

The million dollar question. Simply put, installation is far more important than the badge on the front. Not what you’re looking for, I know. I’ve serviced and installed most brands and all created happy clients.

It pains me to say it but, the key isn’t so much the brand but the exact recipe that suits your needs, budget and the guy you like or trust.

Also, not all makes and models are available in every region, town or city. Each city has their unique distribution and support networks.

All furnace manufacturers have multiple equipment lines. Premium brands & Value Brands.

The premium brand is their flagship and customarily protected. It’s usually only offered to established contractors with a reasonable reputation and considerable volume numbers per year.

The value brands typically have lesser warranties, smaller contracting companies and a few cheaper components. Surprisingly though, some are exact copies of the premium line! Just a different badge.

Lennox has Armstrong Air and Air-Flo. Daikin has Amana and Goodman. Trane and American Standard have Ameristar. Etc.

The reality is that today’s globalization market, for the most part, all of the components are made by the same manufacturers and interchangeable with each other or universal replacements can be used.

High-Efficiency Furnace Warranties!

The naked truth about furnace warranties.

Furnace Heat Exchanger Warranties

All furnaces in Canada come with a manufacturers warranty. HEAT EXCHANGER warranty & PARTS warranty.

Heat exchanger warranties have become very important because in the past ten years “cracked heat exchanger(s)” is the #1 reason why most furnaces are failing.

New High-Efficiency furnace heat exchanger warranties are all considered LIFETIME and cover both primary and secondary.

LIFETIME could mean 20, 25 or 99 years depending on the brand. Some manufacturer warranties are attached to the equipment and some to the owner, you should get clarification from your contractor (written not verbal) OR ask for a copy before the installation date.

Heat exchanger warranties mean you will receive a new heat exchanger but still have to pay contractor labor. The average is $1500 to install a warrantied heat exchanger.

Some contractors will also charge you for the heat exchanger itself and reimburse once they get compensated from the manufacturer. May take up to six months.

Furnace Parts Warranties

Parts warranties are standard five years but once registered, most get bumped to 10 years. Any working part inside your furnace is replaceable for the next ten years.

Some manufacturers require annual maintenance/service for the warranty to stay valid but not all.

The Increased numbers of incorrectly sized or improperly commissioned high-efficiency furnaces are causing some manufacturers to “site visit” or require a “combustion analysis” before honoring warranties.

Parts warranties don’t cover neglect or maintenance related issues; I.E dirty flame sensor or plugged condensation drains.

Furnace Labor Warranties

Labor can be offered by the manufacturer or the installing contractor.

Most manufacturers offer three, five or ten-year extended labor warranties to pair with their parts warranty.

Most manufacturers only give 30 days to make this decision, but some allow up to five years after the installation date. 

Labor warranties cover the hourly rate to replace a warrantied part on your appliance. When labor warranties get purchased from the manufacturer, they also include the dispatch fee!

A new trend in Canada is for contractors to offer in-house labor warranties! They will provide anywhere from 1 to 12 years!

Some will mandate annual servicing and others will not. In both cases, contractors aren’t insurance brokers, and it’s not a valid warranty. If they go out of business, refuse to honor the terms or cannot accommodate you promptly, you’re on your own.

Almost all contractors will charge you for a dispatch fee, especially on a warranty call. These charges can become very high when outside of regular business hours and during peak seasons.

My Advice

If the warranty and peace of mind is a major deciding factor, you should purchase an extended labor warranty from the equipment manufacturer.

It protects you and your contractor; you get reliable, guaranteed service and they get compensated fairly (hourly rate to serve you and also for the travel time to your home).

A lot of contractors don’t like those terms because they can’t charge you at will and inflated prices.

If your installing contractor no longer answers your call or makes you wait too long, directly call the local wholesaler of the manufacturer and they will offer up other brand certified contractors that can handle your warranty.

All manufacturers will provide a warranty certificate to verify you indeed are covered. Also, you can check your warranty status online.

Manufacturers websites all have a warranty section. Just enter your model and serial number to see how much coverage you have.


One last point, some manufacturers allow transferability of warranties for free but the term length shortens, and some will charge a small fee.

What You Should Expect When Getting An Estimate.

Furnace Estimator Not a Salesman

You should shop like my wife, get three quotes.

Give the contractor your attention and time. They can only help you if they know your issues, goals, and budget. Expect about sixty minutes for the process.

Contractors offer different opinions, brands and ways of doing things. You will learn a little from each. I would avoid any company that can’t send out an experienced estimator, a salesman without any real industry experience just doesn’t cut it anymore.

Get A Price Guarantee

Experienced estimators who’ve installed before know what to look for and can offer you options that are accurate & correct. You should be able to get a pricing guarantee in writing that once the install starts, no extra charges can be applied.

Site Inspectiontion

A professional contractor will inspect the mechanical room set up, measure all the windows, exterior walls, and ceilings. Count all the vents, measure airflow, and thermal scan any trouble areas if you currently have hot or cold spots.

Based on the details collected, the contractor should provide you with a proper heat loss and gain calculation. It proves they care about the entire process, competency and guarantees accurate sizing.

Questions & Answers

An expert contractor can clearly explain the industry and clarify city codes, the different brands, models, your application details, warranties and address any other questions or concerns you may have.

Proposal Options

They should be able to build and leave you quotes and discuss your options based on all the info provided. 

A great contractor doesn’t have to resort to pressure tactics to earn your business but should be able to help you through the decision making process.

6 Common Industry Terms SIMPLIFIED…


Annual fuel utilization efficiency. The percentage a furnace can convert burned gas into real heat in your home. The higher the number, the better.


Electronic communitive motor. A type of DC power motor. Uses less energy to perform the same job. This motor lowers your electricity bill.


An enhanced version of the ECM. The most energy efficient motor available. The quiet and continuous operation help with better air distribution and enhanced air quality.


Simply a valve that can produce varying amounts of heat depending on the demand of the home. Most efficient gas operation on the market to date.

Heat Exchanger

 The metal component inside the furnace where heat gets transferred to your homes ducting system. There are two heat exchangers (primary and secondary) in new high-efficiency furnaces. The extra 12-15% efficiency on high-efficiency furnaces comes from the secondary heat exchanger.

Communicating Thermostat

A proprietary thermostat paired with the furnace that squeezes the maximum energy savings and performance out of the equipment and gives enhanced control over the machine. Usually, require four wires from the thermostat to the control board to operate.

Proudly Serving Calgarians since 2005!

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