Giammalvo Files
Mark Giammalvo

Mark Giammalvo specializes in driveability diagnostics at his family business, Sam Giammalvo's Auto Sales & Service, Inc. in New Bedford, MA.   

Mark, who has been with the business for over 20 years, is an ASE  Master Technician and Parts Specialist. He also holds the ASE L1 certification, and has an associates degree in business management.
Mark is also a writer for Motor Age Magazine and is the past secretary of the Alliance of Automotive Service Professionals, (AASP).

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What! Information Lockout Again?
But it's Just a Dehumidifier!

(Printed in the Journal of The Alliance of Automotive Service Providers, AASP) 

Ok, your thinking, here he goes again complaining about the lack of automotive repair information. Well, repair information yes, but not automotive information this time. Still stumped? Read on:

Two years ago I decided that I was tired of the sticky cellar syndrome. Tired of the squish squash sound that my shoes made when I walked around in my cellar at home in the summer months as the latex floor paint started to bubble up in the humid weather. At that time I went to Home Depot and purchased their best model (Maytag 65 pint) dehumidifier.

Although it added to my electric bill more than expected, it sure worked great the first year. I had the unit set to automatically drain via a hose into my sump pit. That saved me from having to dump out the water bucket twice a day. I just turned it on and let it run.

I noticed in the users manual that my model had an electronic defrost feature. Although the explanation of this defrost mode was only two sentences long, it appeared that my model had the ability to sense ice on the evaporator and thus go into a defrost mode to melt the ice. On one cool spring day back in 2005, I remember hearing the dehumidifier's fan suddenly on high speed. When I inspected the unit closer, I noticed that the dehumidifier had shut off the compressor and defaulted to high speed blower. I then looked inside and observed ice melting off the evaporator. In a sense, I had stumbled on part of the strategy of this units computerized defrost cycle.

All was well until spring of 2006. In late April last year I noticed the cellar getting musty and decided to get the unit ready for the season. I cleaned the air filter, plugged it in, turned it on and let it go. One day later, I noticed that the unit was now very loud and vibrating. I looked behind the air filter and noticed that the evaporator was now encased in a huge block of ice. Strangely enough, the compressor was still running and the fan was on low speed. It appeared that the defrost mode was no longer working.

Later that week I contacted Maytag and was advised that my unit had a 5-year warranty. The Maytag repair center put me in contact with a local appliance repair shop in the area. At this point, arrangements were made for me to drop off the unit and I did so. Several days later, I received a call from the technician at the repair shop stating that my dehumidifier was functioning normally and that they were not observing any icing on the evaporator.

Although I was not to happy with this response, I had no choice but to pick up the unit and try it again in my home. Not even a full day had passed when I could hear the odd vibrating sound coming from the cellar. After inspecting the unit again I observed heavy icing on the evaporator. I continued to let the unit run and decided to bring it back to the repair shop again the next day, this time, fully iced over. Let me tell you, this thing was heavy before but it weighed a ton now. It was sort of like transporting a mini-iceberg.
Now I showed the service technician how the evaporator was barely visible, now encased in a block of ice. Needless to say, after a week of running at their shop, they called to tell me that the ice had melted and the unit never iced-up again for them. In polite terms they told me to pick up the unit and not bring it back.

At this point, I wanted to send this thing through their display window but I know that's not the civil thing to do, and besides, I didn't buy it from them anyway. Sort of a: "Don't shoot the messenger" issue you might say.

Now fuming back home, I called Maytag Corporate again and explained my dilemma. The Maytag representative then suggested an alternate warranty service provider, about 50 minutes away from me. Armed with the phone number I called this service shop and was told to drop the unit off in their unlocked dumpster at such and such a location. What? That's nice, I'm going to drop off a 200-dollar dehumidifier in a dumpster on the outskirts of Boston. Right!

To cut this story short, I wound up living with the problem. The icing only occurred early in the season and once June hit, the unit worked fine all summer.

This year I tried running the unit again, this time in early May. Sure enough, the ice came again out of nowhere, like a spring snow storm. At this point, I recalled that I had purchased the factory service manual several years ago for my Maytag electric wall oven. The service manual was helpful and even showed how to extract fault codes and their meaning. (Yes home ovens now have fault codes. It's gotten that crazy). I called Maytag and asked to purchase a service manual for my dehumidifier. Things now got interesting. The Maytag representative stated that my Maytag dehumidifier is actually made for them by the Fedders Corporation and that, although they do not have a repair manual for this model, Fedders may offer one. Now I called Fedders and questioned them. Astonishingly, they admitted that there is no factory repair manual for Fedders or Maytag dehumidifiers. The only published items are the owners manual and a copy of the wiring diagram which is already on the inside front cover of each dehumidifier. How the heck do you diagnose and repair this thing? Strangely enough, I guess they use the "Buy it and try it" parts replacement methodology.

Now, as frustrated as ever, I decided to open the unit and take a peek. What the heck, if I break something I'll just throw the whole thing out at this point. Besides, what value does the 5-year warranty have anyway? With the case split open, I noticed a sensor clipped to the side of the evaporator. Presuming they mounted this sensor here to sense evaporator temperature, I removed it from its bracket for a closer inspection. The sensor was a 2-wire type with about 2 feet of low voltage wire that plugged into the electronic control panel.

Browsing Google with my model number proved interesting. This sensor is sold with the actual control panel. All and all its about a 40-dollar part and seemed easy to change. Had I brought home a volt/ohm meter I would have checked to see of it was stuck open or closed. Then again, with no test information available, anything would be a guess at this point. I decided to move the sensor from the side of the evaporator and place it right in direct contact with the face of the evaporator. I reassembled the unit and gave it a run. After 1.5 hours I watched as the evaporator started to ice over. Suddenly, the compressor shut down and the fan went to high blower. Alas, the defrost cycle was working again. Had I repaired it with the alternate placement of the evaporator sensor or was this just a coincidence?  All I know is that it seems fixed for now.

To think I thought that information lockout just affected the automotive industry. All I can say is, good luck to you if you're a home appliance repair technician. Better keep a lot of spare parts on hand and be ready to re-engineer things as needed.


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