Bad Furnace Installation - What To Watch Out For

Bad Furnace Installation - What To Watch Out For
Arne Jacobsen
Residential Sales Professional

I have been in heating and air conditioning trade for 44 years. In that time, I have installed, serviced, designed ductwork, sold, and sized thousands of residential heating and cooling systems.

About This Article

What are the signs of a bad furnace installation? We run through what to look for and how to avoid it.

If you get a new furnace, it’s making a decision that’s going to last you 15-20 years, or more.

Or, at least, it should be that long.

The fear is that you make the wrong decision with your choice of HVAC installer, and the result is a system that gives you more problems than it’s worth.

Is this rare? Sure. But you know what else is rare? An installation that does everything right the first time. Most HVAC contractors can get your unit up and running, but unfortunately, this isn’t enough for it to be a “good” installation.

This is why contractors sometimes get a bad name. It’s also how they cost you money without you knowing about it. HVAC is a complicated industry, and it’s not your responsibility to know all the in’s and out’s of the installation process. But that’s also why an unscrupulous company can take advantage of you by cutting corners.

Don’t believe that it’s too complicated to understand? Check out the links below briefly. They’re nearly 10,000 combined words from our installation manager on the proper processes for air conditioning and furnace installation. And in my 40+ years in this industry, I can say with confidence that well under half the companies in any area will do everything on those lists.

ALSO READ: Air Conditioning System Installation Process From Start to Finish

ALSO READ: Furnace Installation Process From Start to Finish

We’re here to help. The processes above are ones we go through on each installation. Even if you aren’t in our service area, you deserve quality installation the first time a furnace is installed. How should you ensure that? Well, that’s what this article is about.

Consequences of a Bad Furnace Installation

I’m not going to sugar-coat this or beat around the bush. Here are the consequences:

  1. Shortened lifespan for your furnace
  2. Lower efficiency, even if it’s a high-efficiency furnace
  3. That last one means higher utility bills
  4. All of this means less comfort for you, and more headaches as you deal with a sub-par system

We’re going to break each of those down below; what they mean, why they happen, and how they can be avoided. But the bottom line is that you’re putting several years’ worth of comfortable operation at risk if you receive a mediocre installation.

There are two primary reasons we see that lead to these issues:

  1. Lack of installer knowledge
  2. Deliberate cutting of corners to save costs

Here’s the biggest reason why these things are so diabolical: most sub-par installations won’t cause major issues for 8-10 years, which is why it’s tough to catch. A contractor can just shrug at that point and say “these things happen.” But for you, it could mean having to buy a new system 10 years later instead of 20.

Random problems do occur in HVAC systems, but they happen a lot more predictably when certain steps aren’t taken.

Furnace Tune-up

Cutting Corners in Furnace Installs

Believe it or not, the biggest thing I usually see wrong with furnace installation isn’t with the furnace itself. It’s with the ductwork.

HVAC systems are just that: systems. A furnace doesn’t operate alone, but needs proper ventilation, ductwork and infrastructure in order to do its job correctly. As we’ll talk about shortly, there are a few things with the furnace itself to watch for, but it’s generally everything else that gets ignored.

A return air drop is a portion of ductwork that allows air to travel back from your home down to the furnace. This allows for correct airflow. The danger is that the return air drop isn’t large enough to support your furnace. If this happens, your furnace will be starved for air since it won’t be receiving enough air to do its job in supplying new, warmer air to the house.

This is a minor charge to fix during installation, but is a major difference in the performance of your furnace unit.

Another area that is often neglected is ventilation. If you have a “standard” 80% efficiency furnace, it will generally vent out of a masonry or metal chimney flue. If it’s a 905 or higher “high-efficiency” furnace, it will require a plastic PVC drain line to vent properly.

These are installed by anyone who puts in a furnace. But they’re not always installed well.

The PVC pipe can only be so long before it’s no longer within manufacturer specifications and you start to run into problems. If the piping has to go through numerous turns before it reaches outside, this adds to the length. Too many turns can result in your furnace breaking down due to vented air backing up into your system.

Similarly, the PVC pipe needs to be shifted to a certain angle. I’ve seen many that are level instead of angled. This means your unit won’t vent and drain correctly, which can cause long-term problems.

Are there other potential cut corners in installation? Yes, absolutely. But to list them all would end up being a bit too exhaustive. We’re going to cover some other areas below, but these are the most frequent that I’ve seen as I inspect houses and talk to homeowners about their heating needs.

Calibrating, Commissioning and Matching

Ok, so your new furnace is installed, and it’s turned on and is producing heat. You’re done...

...right?? Well, not quite.

Imagine you’re cooking Thanksgiving dinner and you’re not sure if the turkey is done. You open the oven, eyeball it, and say “yeah, that looks good enough.” Is this enough to ensure the bird is cooked?

“Is it producing heat” is kind of like looking at a turkey to determine if it’s done cooking. With the turkey, you’re measuring the internal temperature to make sure the insides are thoroughly cooked. In HVAC it’s kind of similar, but it’s a LOT more than one measurement being taken.

Take the blower motor, for instance. It runs the fan that moves air throughout your entire home. ANY fan will move air through your home, but the calibrations on the fan should be tuned to your specific system.

Each fan comes with factory settings. Sometimes those settings are adequate. Often, it requires additional wiring and calibrating to make sure it can perform all of the airflow duties that your furnace should be capable of.

What happens if you don’t do this? You’re only getting a fraction of your furnace’s functionality and efficiency. You might have paid $5,000 for your furnace, but you’re only getting $3,500 worth in terms of flexibility in airflow to meet your home’s comfort needs. It’s no cheaper to have it set up this way, and it’s no more work for you. It’s just worse.

Commissioning is the process that, among other things, checks pressure levels in the furnace to make sure it’s operating within manufacturer specifications. Our commissioning reports can have over 40 different data points on them, and each one is important. The blower fan example above is just one example. Your entire system needs to be fine-tuned, not just installed, for it to run well.

RELATED: The Importance of Commissioning in HVAC

So if you want an undercooked turkey...er, I mean a sloppy, incomplete furnace installation, the installer can leave immediately after they confirm it’s producing heat. But if you want it done right, you need more.

Inspecting a furnace

Under Pressure: The Missing Metrics of Furnace Testing

I don’t think I can stress enough how often pressure testing is skipped, and how much it can mean for the life of your furnace.

Take gas pressure, for example. Many furnaces here in Columbus, OH use some form of gas as a fuel. If a gas valve has a traditional valve that requires a wrench to close, we’ll remove it and install one that a homeowner can operate by hand. This is good for emergencies and is a necessary safety precaution.

But when a furnace changes, the necessary gas pressure to fuel it might change. If an installer isn’t testing this (and many don’t), they’re leaving it to chance.

Static pressure is another big culprit. Static pressure deals with the pressures of the air on your system at nearly every stage of the heating and cooling process. Static pressure kills systems years before they should be in need of replacement. It involves the ductwork size and shape, the blower motor, the filter, and the furnace itself. As such, it requires a lot of testing to make sure everything is operating smoothly.

Even something as simple as moving a furnace from an open area to a smaller room or basement closet can affect airflow. If you want to get the most out of your furnace, this needs to be accounted for.

Do you want to know how many companies check static pressure after an installation? I don’t have an exact percentage, but it’s not very high.

Dangers of a Bad HVAC Installation

The true dangers aren’t the things we talked about earlier like cost and shortened lifespan. Those things are bad too, but it’s not the reason this continues to happen.

The danger is that homeowners don’t know these things, so a company that skips some or all of them is not being held accountable.

This is why a big part of what I do is educational. When I come into a home, my job isn’t just to sell you something. It’s to help you understand the considerations that go into a good HVAC decision.

Being Proactive: Do Your Homework, Make the Right Contractor Decision

Fire & Ice is in business because we cross all of our T’s and dot all of our I’s in the installation process. It’s what lets me sit down at the dinner table with a potential customer and talk about all the different things we do that our competitors won’t.

RELATED: The Fire & Ice Difference

But when we struggle, it’s because those who are cutting corners aren’t educating homeowners, and as a result, a mediocre installation for less money seems like a better deal than a great one for a bit more.

We’re not always going to be the right choice for customers, and there are other companies doing good work, both here in the Columbus area and nationally.

But we wouldn’t be writing this article if it weren’t a problem. It’s a big one, and it’s why HVAC as a whole sometimes (justifiably) has a bad name.

Don’t let yourself be taken advantage of. Educate yourself and be prepared.

One, check out our Learning Center for more. There are a few links above and I’ve included more below. Even if you don’t go with Fire & Ice, you’ll be well-prepared to ask the right questions of the company you choose.

RESOURCE: How to Know Your Heating & Cooling Company Cares

RESOURCE: Cost of a New Furnace

RESOURCE: The Complete Guide to Home Furnaces

Speaking of questions, below is a form you can download that will provide you with 10 questions you should be asking at every estimate.

HVAC Contractor Checklist
 









Put an armor of information around yourself and you’ll be prepared to make the right call when it comes time for your next furnace investment!

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Explore our learning center. It's a comprehensive section focused on answering your questions, providing detailed information, and tips that will improve buyer education when it comes to your home's HVAC system.

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