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HVAC evaporator service problem?

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  • pitboss000
    Remove the triangular shaped side panels from the coil. While its a tight space, it will give you access to clean the underside.

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  • blue_can
    Yes some evaporator coils cannot be fully cleaned without removing them from the system. You can clean them from just one side. If the coil looks clean I doubt you will gain anything by cleaning. Unlike the condenser coils evaporator coils are self cleaning due to the condensate formed. There are some situations where they get dirty - animals in the house where the filter does not catch the pet hair, leaks in the return ducts etc. These will then stick to the wet evaporator coil.

    Foaming cleaners are not a good idea. The tend to etch the fins. You can get some good pro grade coil cleaner, mix with water and use a garden sprayer to spray the coils.

    Yes typically a trap should be installed along with a cleanout. It looks like in your system the condensate drain is at a positive pressure system. A trap is not as essential as one in which the drain is at a negative pressure. In these situations condensate can get sucked back up and mixed with the air and wet the ductwork and even have moisture forming on the registers.

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  • paulmars
    started a topic HVAC evaporator service problem?

    HVAC evaporator service problem?

    This HVAC central unit was installed in 1991. No maintenance service ppl have ever opened the evap door or foamed out the condenser.

    I just opened the evap door and I see that there is NO access to below the coils. Not even from the air handler/furnace. So, I cant even see them. Is it useful to still spray the top side of coils with the cleaning foam? I could only spray 2 of the three coils.

    Ive read yearly service should include:

    "The underside of the evaporator should be cleaned with a stiff brush. When the coils are free of dust and dirt, clean the tray below the evaporator". I cant do this at all.

    So, I dont know if there is a tray or how dirty it might be. Foaming the coils from the top might make the tray worse. Note that the drain works fine. I recently got the manufacturer's installation document online and it mentioned installing a trap. There is no trap in mine and yes I can see the entire line.

    So, should I spray them from the top?

    evap unit is CAC BDP Carrier model CK5(A,B,P)XW024017