When I started in the trade in 1999 there were still a lot of oilable blower motors in service. As part of the maintenance, we would remove the housing, oil the motor plus vacuum / wipe it down.

As oilable motors have become extinct I see fewer and fewer techs pulling the blower housing. Here are some reasons you may want to consider doing it more often.

  • Cleaning the motor itself can help it run cooler and last longer. A hot motor not only is more susceptible to winding breakdown but also to bearing/lubricant failure. Grab a vacuum, soft bristle brush, and a rag and get the dust buildup off the motor. If you have any dust that gets stuck inside, use some low-pressure nitrogen or compressed air to get it clean.
  • Get in there and look carefully at the wheel. A wheel that is even slightly dirty can have a significant effect on air output. If it’s dirty,  recommend cleaning.
  • Check the blower bearings, it’s easier to do when it’s out
  • On high-efficiency furnaces pulling the blower is a good way to check the secondary heat exchanger. On 80% furnaces, you can check parts of the primary exchanger and even the evaporator coil with a mirror or inspection scope.
  • Pulling the blower gives you the ability to wipe down the inside of the furnace or Fan coil.
  • You can check blower mounting bolts and set screws as well as blower alignment and balance more easily.

Obviously, when and why you pull the housing will vary from contractor to contractor but I advocate it being done more often than it is now.

What say you?

— Bryan

I need to warn you…

This is the actual process we use at the company I own for our typical “standard” residential maintenance. I’m sure you will find some things you do differently. Take it for what it is and I’m happy to get any feedback you may have.

  • Read the call notes, property notes and customer notes. Check the last service call and last notes and readings so you are aware of the service history.
  • Check the filter size and ensure you have the PROPER filter if possible
  • Wear shoe covers in the home, ask the customer if they have noticed anything unusual with the system.
  • Inspect and set the set the thermostat to run, shine a light in the return to check for filters, blockages, debris or damage.
  • Visually inspect the system operation to make sure all of the components appear operational before beginning the maintenance. Note anything out of ordinary you observe to the owner and address / diagnose before proceeding.
  • Remove disconnects / shut off breakers. Check for proper breaker sizes and inspect disconnect wires, lugs and pulls.  
  • Remove the condenser top and panels and place them carefully in the grass away from damage.
  • Remove any debris from the bottom of the unit. Inspect wires and compressor terminals while doing this. Use a vacuum to remove dirt and leaves as required. If grading is poor, use a shovel to scrape dirt/leaves away from the base of the unit.
  • Wash the coil well, starting from inside out and from top to bottom. Only use coil cleaner according to the labeled dilution and only use it when the coil requires it.
  • Check the inside of the condenser one final time for any potential wiring or copper rubouts and repair / isolate as required. Note any rust on the compressor, roto locks or accumulator.
  • Inspect the crankcase heater if the system has one. Confirm operation by amperage or ohming out.
  • Look for any signs of refrigerant oil (potential leak points)  
  • Replace the top carefully, ensuring that you don’t pinch any wires. Rewire the fan.
  • Inspect all wiring connection in the condenser control box for tightness and damage. Check contactor points and note condition.
  • Move inside, if the air handler has a finished floor around it, lay down a drop cloth. Always keep the work area inside clean during and after work.
  • Check the evaporator coil condition and cleanliness top and bottom. If the coil is a slant coil orientation and has any dirt on it clean the surface with evaporator coil cleaner, pump sprayer, rag and a soft brush.  If the coil is dirty and an A or another coil type that cannot be easily cleaned in place you may quote a removal and clean if the coil has no known leaks and is less than 7 years old.
  • Connect a wet vac to the drain outside
  • Remove the panels from the air handler and begin pouring water into the drain pan all the while helping any sludge in the pan get removed by moving it toward the pan outlet. Use duct tension straps or zip tie ends / small bottle brushes to help pull sludge out from the sides of the pan under the coil and clean all channels.
  • Run a minimum of 2 gallons of water through the pan and then empty the vacuum. Run another gallon through and repeat the process until the pan is visibly clean and the water in the vacuum is clean.
  • Run 1 more gallon through the drain one done and ensure it runs out.
  • Spray and wipe down the inside and outside of the air handler, including wires with a safe anti-microbial solution.
  • Remove any dust from the blower motor body and end bell with a vacuum, rag or soft brush, being careful not to force dust further into the motor. When the dust buildup is severe, use compressed air or nitrogen and a vacuum to remove it.  
  • Test the blower capacitor by removing the leads, testing with a capacitor tester and reconnecting the leads.
  • Inspect the blower wheel for cleanliness. If it is dirty check the particular maintenance type to see if removing and cleaning the blower is extra or included.
  • Check the blower motor bearings for play.
  • Inspect all wires for rub out inside and outside the air handler. Inspect and disconnects and check any lugs for tightness.
  • Check low voltage wiring and dip switch/pin settings. If the system has an advanced interface you will need to check for proper settings at the controller.
  • Check coil feeder tube location and condition. If tubes begin to rub out, isolate them and strap them together using foam tape and zip ties.
  • Inspect the float switch for proper installation and wiring. Test the float switch to ensure it breaks the circuit when the float rises. If there is no float switch, quote to install one at the end of service. 
  • Check air handler panel insulation, glue or retape as required.
  • Spray down the coil surface lightly with antimicrobial and add 3 pan tabs to the front of the drain pan away from the outlet.
  • Install a new air filter with date and your name.
  • Replace the bottom air handler panels and turn the air handler breaker on.
  • Run the heat and test the heat strips on and off using an amp meter. Note heater and blower amps.
  • Shut off the air handler, replace all panels and double check the drain cleanout cap is in place and the float switch is in the correct position.    
  • Put the system into cool mode and turn the air handler back on (condenser disconnect still off / out)
  • If the system has been checked during previous calls and has no history of leaks then use the historic data to perform a Non-invasive refrigerant test. If this is the first maintenance or if the system has a history of issues then connect gauges.
  • Connect an amp clamp to compressor common and observe as you turn on the condenser breaker/disconnect.
  • Test the L1 & L2 voltage and ensure it is in the acceptable range
  • Allow the system to run for at least 10 minutes. During this time you can Begin Cleaning up
    1. Start filling out the service call/collecting model and serial numbers if required
    1. Inspect suction insulation and thermostat wire outside for damage or poor splices
    1. Perform the “under load” capacitor test
    1. Read across the contactor points to see if there is any voltage drop in the contact points
  • Once the system has run for 10 – 15 minutes perform either the non-invasive test protocol or check and note suction, head, superheat, subcool and delta T according to the “5 pillars” tests and any manufacturer guidelines.
  • If the system is a heat pump, test the opposite mode (usually heat) to ensure the reversing valve shifts properly and the system runs.
  • Note and suggested repairs or improvements to the customer and get their response.
  • Clean up fully and double check drains refrigerant caps and disconnects. Call in standby.
  • Wrap up paperwork with the customer.
  • Ask the customer if there is anything else you can do to make their experience better and if they can think of any way you or the company could improve.
  • Complete all call notes, finish timesheet entry, neaten van in preparation for the next call.

   — Bryan

P.S. -Since publishing this article the first time I’m always asked how long we “give” to do it. With a maintenance this complete the time it takes will vary a lot and can be done in 45 mins on a new clean unit all the way up to 2 hrs.


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. 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.

This is ACTUALLY how I performed a 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 (like shown above) you risk twisting / damaging the wires, scratching the paint and bending the fan bade.
  • 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 because that dirt can reduce coil capacity as well as hold moisture against the base, compressor and accumulator resulting in corrosion.
  • With the top off you can get a better view of any wire rubouts or potential wire rub outs 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 a terminal failure / “blowing a terminal”.

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

So what do you think?

— Bryan

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

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