Pull The Top

The photo above is from a video one of my techs took of proper condenser cleaning. I must say, he did a GREAT job of cleaning the coil, and he was very careful with the top. However, I STILL would have liked to see the top get completely removed during a full maintenance procedure. Pulling the top usually just requires disconnecting the fan wires, cutting a few wire ties, taking out some screws, and then removing the fan grille or the entire top and laying it top-down in the grass.

That is ACTUALLY how I performed maintenance, even before I started my own business.

Here is why:

• If you wash from the outside in, you are not doing the best possible cleaning. Everyone knows that washing from the inside out is a superior method of cleaning.

• If you lay the fan on top of the unit (as shown above), you risk twisting/damaging the wires, scratching the paint, and bending the fan blade.

• When you pull the top entirely, you can more easily clean the dirt and leaves from the inside of the condenser; this should also be part of a proper maintenance procedure because that dirt can reduce coil capacity and hold moisture against the base, compressor, and accumulator. That moisture results in corrosion.

• With the top off, you can get a better view of any wire rubouts or potential wire rubouts and address them before they cause a problem.

• You can also visually inspect the compressor terminals for signs of heat and corrosion, potentially preventing a major issue such as a terminal failure or “blowing a terminal.”

Obviously, it will take about 5 minutes longer, and you will need to rewire it properly with the terminals snugly installed.

So, what do you think?


P.S. – Here is the video in case you want to see what I mean, and yes… he knows that cleaner isn't always required when washing a coil, but he used it for demonstration purposes.

Related Tech Tips

Tunnel Vision and How to Avoid It
How many times has the following situation happened to you? You're on your way to that final service call. While you're listening to the customer explain their complaints over the phone, there's this precise moment where you've thought: “I know what it is already. This will be a quick one.” Sometimes, intuition proves to be […]
Read more
Fire Damper Tips
Tech Brandon Livingston posted about fire dampers and took some photos shown here. He gave me permission to share this here, and his original post inspired this tip. Thanks, Brandon. The picture on the left shows the situation before the damper was opened. The right image show what happened after it was opened and a […]
Read more
Think Before You Drill
Over the last 30 years, there has been a big move away from conventionally framed roof structures towards engineered structures— specifically engineered trusses and load-bearing engineered beams like micro laminated and even steel. I have been in so many attics where the engineered roofing or other load-bearing structures have been cut to accommodate equipment, wires, […]
Read more

5 responses to “Pull The Top”

  1. Completely agree with your procedure. Without top removed very unlikely a complete vacuum of bottom of outdoor unit occurred, thorough vacuum/clearing all drain holes, and thoroughly inspecting the compressor and, if ASHP, the RV for wiring/pipe issues and the accumulator (typically). Please keep preaching/teaching the proper sometimes more tedious procedures. Thanks.

  2. can you do a video on how to clean a double coil on a roof top unit. I am a one man show and want to see if you have any tips I could use. thanks !!

  3. I agree with this. Some commercial units, the tops can be removed or access panels removed to clean coils better. I never thought to use a vacuum on the bottom basin. This is a good tip. I would like to see tips on indoor coil cleaning/inspection and so forth.

  4. A wise man once told me, since the fan is pulling air/debris from the outside in, always clean with water from the inside out. This is most effective in removing dirt and debris from the fin area. It always makes me nervous to see people when they try to clean with a fan motor and blade balanced so precariously on top. Although I must admit I have come across several units that there is so little slack in the wiring the top could barely be removed without first disconnecting the wiring.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.


To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from