What’s the Required Service Area for HVAC Installations?


Installing Equipment Safely and to Code for our Sacramento Customers

When we install HVAC equipment in people’s homes, there is a code that covers how much service area there needs to be in front of the equipment.  That’s what we are talking about today on Code Corner.  Let’s take a look at what the codes say and adhering to to the code when doing an HVAC change-out.


I’m not here to pretend I know or could even interpret all the codes correctly.  I’m simply trying to open a conversation about codes we cite on the job every day out there without even knowing it.

But where is that code in the book?  That’s what this project is all about.  Ultimately, this project is good information for technicians but if they help you, then that’s great!  And good for you for even caring about the building codes enough to read this blog post.  It means you care about your work too!

Let’s take a look at what the codes say about Required Service Area in front of the HVAC equipment and adherence to the code when doing an HVAC change-out.

Making Space

Have you ever been in front of a furnace in the attic, and noticed you don’t have enough space to work?  Imagine you need to pull the heat exchanger from the furnace and change it with a new one.  If there’s not enough room in front of that furnace, the technician won’t be able to remove and replace parts as needed.   And trust me, this accessibility issue is a major problem because if we can’t get that blower motor out, a more invasive procedure needs to be carried out to extract the part which will cost the homeowner more money at that time in the future.

This has already happened to people a long, long time ago, and they learned from it; And they wrote it in a book so that future techs won’t make the same mistakes they did.

Now, imagine you’re trying to perform a regular maintenance, but can’t get the access panel off the AC because a giant lattice structure has been solidly built around it.  The homeowner doesn’t want to LOOK at this horrid AC in the back yard, so they cover it up.

Well, the builder of the lattice structure at the AC, and the installer of the platform or non-existent platform at the air handler in the attic didn’t install this system properly.

CMC 304.4.3 says a level working platform not less than 30 inches by 30 inches has to be provided in front of the service side of the appliance.

IMC 306.1 says the same thing

The exception to this rule is that a working platform doesn’t need to be provided when the furnace is capable of being serviced from the required access opening. In this case, that furnace can’t be over 12” from the attic access either because some techs might not be able to reach components inside the furnace casing.

Now, you know I like to encourage you to read the installation manual while you’re installing the equipment, right?  I personally like to look through it the night before my next install.  That way I know what I’m saying if something comes up during the install with my co-workers.  Usually, the manual has more restrictive guidelines when installing HVAC equipment.  The city and county code inspectors everywhere defer to the installation manual so many times because the manufacturer has stricter requirements for the installation.

Referring to the Mechanical Code

In the IMC, in 102.1 Conflicts in Code, it says if the codebook and the installation manual conflict with each other, to follow the more stringent requirement.

The installation manual for our equipment in the attic says the clearance in front of the furnace and coil in the attic is required to be at least 24 inches.  If the county inspector adheres to the IMC or CMC, and it says 30 inches in front of the appliance, but the installation manual says we can go 24 inches in front of the unit.  Which is the correct answer?

In this instance, the mechanical code is still more stringent on its requirements, so when I hear people say we only need 24” in front of the furnace, I know it will probably fly, but the inspector could call us on it and ask for a 30” service area in front of the unit.  And you need to know that.

The service platform is supposed to be constructed from “solid flooring.”  Many techs around here use 5/8” plywood. I wouldn’t use 3/8” or 1/2” plywood, because it’s pretty flimsy for bigger guys, and over time can splinter and break.  Nobody likes to sit on a flimsy service platform that was supposed to be built “solidly.”  Instead, get the 5/8” thick plywood.  Its only a few more dollars and will be secure for any technician who has to crawl across it.

Avoiding Obstructions and Providing Space

Is it okay if the service platform is uneven?  Like a step up or down?  I don’t think anybody will give you a hard time if the decking for the service area is 4 inches higher at one point than the other.  The point is to be able to pull parts from the unit without any obstructions, like a wall or truss, and have a spot to put your tools and anything else you might need for the job.  So if that step is going to interfere with the changing of any part of that system, it’s not built to code.

Outside at the AC, just make sure you have a 30 x 30-inch area in front of your access panel.  This ensures future techs can get in there and make the necessary repairs to get the customer up and going again.

Consider the Next Installer

If your homeowner is going to build that lattice structure around the AC, ask them to build it so it can be slid out and then back when the AC tech moves on.  Don’t let them pour concrete piles so it’s secure but never going to move again.  That inhibits technicians from doing their job safely.  There’s nothing more frustrating than having to take down the lattice panels around an AC one screw at a time, just so you can get in there and clean the AC so it will work properly again.

As installers, I believe we have a responsibility a to consider the next tech who comes to service this equipment.  He or she might not be 5 foot 8, and 165 lbs.  There are short techs and tall techs, narrow techs and wide techs.

Correct Equipment Installation

That’s what this series is about.  It’s not to say that I know all the codes, and can interpret them perfectly.  Code Corner is about Fox Family Heating and Air wanting to install equipment correctly, so we can pass the inspection that comes with pulling a permit for the job.  Read more about HVAC installations here.

Remember, any time we alter the electrical, mechanical, plumbing and gas lines, we need to pull a permit and follow the codes and the installation manual.  And then we need to have a third party, unattached inspector come by, and just make sure we installed it correctly.  It’s not a bad thing!  We just look at it as an extra set of eyes on our work to make sure the family who resides in that house, and uses that system we installed, is safe forevermore!

Looking Ahead

I have several other topics I want to open a conversation about when it comes to HVAC and the building codes.  I really hope nobody is taking offense on these topics.  My goal is to elevate the HVAC world and make us all better technicians so we can go out and take care of our customers safely.

Comment below if you’ve have had any weird platforms or service areas so tight you couldn’t service the AC!  I’m sure you all have some great stories.

Thanks so much for watching and we’ll see you at the next blog.

Don’t Stop…Believing (in your HVAC system)

HVAC repair Citrus Heights

On Sunday, we got a call from one of our customers last year who asked a different company to come out and service their AC system since it wasn’t working. So, the company comes out and tells them they have a clog in the coil and the refrigerant is low. There is nothing they can do about it. They have to get a new system. Here’s the weird thing about it: It’s a 9-year-old air conditioner.

When she called us, I answered the phone and was delighted to hear she was going to give us a chance to come out and diagnose what the issue was. It sounded like she wanted a second opinion. When we got out there, we discovered her system was running, and it was even cooling fairly well at the moment. But, to her, that was not new information. That is what the system would do. If it had been turned off for a little while, it would run fine. The longer she ran it, like on these 100-degree Sacramento Valley days, the less it cooled.

Our technician Keith went out to the house in the Citrus Heights/Orangevale area. When he put his gauges on the system, he noticed a fairly low pressure on the suction side of the system and a pretty high pressure on the high side. This was strange because the house was warm. There should have been higher suction line pressures than what was showing. Keith let it run for about thirty minutes before confirming something was indeed wrong with the pressures in the system.

A measurement in the field we take often is called superheat and subcool. It’s a measurement of how much liquid refrigerant is in the copper lineset that runs between the indoor system and the outdoor system. Ideally, you’d like to see a balanced measurement of subcooling and superheat in the system. Too high or too low and it’s a sign that something is up with the system.

In this case, the subcooling was around 30 degrees. The superheat was around 35 degrees. Both were too high for this particular day because of the temperatures outside. Keith called me to confirm his suspicions. He had checked the airflow through the system. The return duct wasn’t crushed. The evaporator coil was clean. The filter was clean. All the registers in the house were open. But still, the pressure did not indicate a healthy system.

There is a device in some systems called a thermal expansion valve. It meters the flow of refrigerant into the evaporator coil. The evaporator coil is the “cold coil” that the air blows past to give you the cold air that runs through the ducts and into your rooms.

In this case, the expansion valve is not metering correctly and does not meet factory specs anymore. Simply changing this part out with another factory provided expansion valve will get this system up and running again. The owner of this house was super happy that we can fix her 9-year-old system for a fraction of the cost of a new HVAC system.

If you ever run into a situation where you are not feeling very sure about a company’s decision to spend your money, call for a second opinion. We saved this lady thousands of dollars by carefully pouring over this system. Looking inside the copper tubing and diagnosing how the system is running is a more professional and ethical way of treating our customers.

So, don’t stop believing in your HVAC system just because some company tells you to buy a new system. Almost everything on the system can be repaired if that is what YOU want to do. Make the technician repair if that is indeed what you want to be done.

For a free second opinion, simply show us the invoice from the other company you paid a service fee to and we’ll come out and happily make a thorough investigation on your system to give you the right answers. Call us at 916-877-1577 anytime!

Sacramento HVAC Company Reviews

HVAC company reviews Sacramento

Fox Family Heating, Air and Conditioning | Sacramento HVAC Company Reviews

Learn what our clients say about working with us. Owners, Greg and Melissa are focused on customer experience over sales every single time. We believe that repeat and loyal customers are the backbone of any company’s longevity. In the competitive HVAC market of Sacramento, our goal is to deliver honest, fast, and friendly five-star service every single time we are invited into a customer’s home.  Here’s one customer’s story.