Dust buildup on auxiliary heat coils

Discussion in 'Maintenance and Troubleshooting' started by geome, Dec 29, 2010.

  1. geome

    geome Member Forum Leader

    For systems that don't normally run auxiliary electric heat, should the heat coils be run periodically to make sure too much dust doesn't accumulate on the them? How many times per year would be prudent? Obviously, dust levels and blower run time will vary greatly from house to house. I assume buildup can occur whenever the blower runs (even in cooling mode.)

    A pre-heating season test is a good idea, but doing this might only amount to one run cycle per year for the heat coil for some systems. Other systems may not even have one run cycle for auxiliary heat due to mild winters, no pre-heating season test, slightly oversized system, warm climate, etc. Have any of you seen problems due to dust buildup on the heat coils, or is this a non issue (other than the smell of burning dust)?
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader


    Same as electric furnace maintenance I imagine. And knowing the manufacturers, I'll assume they recommend annual maintenance. That's my cheeky way of saying, sure go for an annual cleaning, pay someone toomuch to do it, or just let 'er run.
  3. geome

    geome Member Forum Leader

    Thanks Chris. The only annual maintenance (in the fall) our company has done on the heat strips is an amp check to make sure they are working.

    Unless others weigh in, maybe I'll just run the strips for 10 minutes 2 times per year when I can open the windows (preferably without letting very cold, hot, or humid air in.)
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    A bit of stink owing to dust burnoff is normal for any system.

    That said, if excessive dust is accumulating on aux strip elements, then it is also accumulating on refrigerant coil...poor air filtration is to blame. A dirty coil will be inefficient in both heating and cooling modes and ultimately ice up in summer.

    I've taken to gasketing air filters with strategically placed strips of 1/8" thick closed cell foam pipe insulation. That tightens the fit of the filter in its housing and stops air bypassing the filter, the source of dust on coils and strips.
  5. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I think

    ..this is a non-issue, so I agree with Urthbouy. I also would however heed Engineers words.
  6. geome

    geome Member Forum Leader

    Thanks for the good advise. I cleaned the refrigerant coils (2 units) in November. I do this every 6 months now since the 1st year of this included service elapsed. They were very clean, but decided to do it anyway to keep them that way. It has been 1 year since the aux coils were tested. Guess the smell came from the buildup of dust over that time period.
  7. moondawg

    moondawg Member

    I recommend removing them 2x a year and blowing them out with unicorn farts.

    Then set them at the end of a rainbow to dry.

  8. geome

    geome Member Forum Leader

    I take it that you are in the "non-issue" camp as well. LoL
    Last edited: Dec 30, 2010
  9. Feedback

    HVAC techs TEST backup heat strips by making the thermostat or control device "call"; They normally open up the heat section (where the heat strips are located) and put some sort of "amprobe" or current meter on each and every stage of auxiliary electric heat to check or measure current.

    THIS IS SUPPOSED TO BE A FALL CHECK UP BEFORE WINTER HITS. But of course everyone pays a service tech to do do this, right?

    We are doing two things, First we are burning the dust, nickel chromium "stink" off of them and second,we are measuring amperage draw which is the proof that the elements have not burned 'open' and work.

    If you have three stages of additional electric heat, we are verifying, if we are competent, that first stage one draws, say 6-8 amps 230 volts, that stage two then comes on, drawing 6-8 amps, and so on. That burns stink off, and proves that if the compressor locks out, that you have a valid heating back up. Stink is worse on systems where the electric heating wire hasn't (compare to your toaster) been used for a couple of years and is thoroughly coated with dirt and dust. It should not cause a fire, but it may stink initially until the dust is gone.
  10. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    This is still

    a non-issue and HVAC gets paid to do his tests.

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