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Why nobody talks about using a heat gun on stuck refrigerator condenser fans
I was troubleshooting a walk-in cooler at a restaurant in Austin last Tuesday where the condenser fan just would not budge. After fighting with penetrating oil and a wrench for 20 minutes, I grabbed my heat gun on a whim and hit the shaft for about 30 seconds. The fan spun free immediately, like it had never been stuck in the first place. The heat expands the metal just enough to break that corrosion bond without damaging the bearing. I have tried this on three more units since then, and it worked every single time. Anyone else ever use heat to free up seized fan motors, or am I late to the party on this one?
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the_leo1mo ago
Yeah man heat guns are a lifesaver on seized fan shafts. I've done it on maybe a half dozen walk in cooler condensers and even some reach in freezer evap fans. The trick is to hit it just long enough to feel the heat transfer through the metal but not so long you cook the bearing grease. I usually hit it for like 20-30 seconds, then give a gentle tap with a rubber mallet while it's still warm. Works way better than drowning it in PB Blaster for half an hour.
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sean_green441mo agoMost Upvoted
Caught me off guard once with a heat gun on a blower motor shaft (not a fan, but similar idea) and ended up melting the plastic housing a bit because I got too distracted. @the_leo your timing advice is spot on. I've found that if you wrap a wet rag around the bearing area before heating, it helps keep the grease from getting too hot while still letting the shaft expand. Did this on an old commercial ice machine fan where the shaft was basically welded in place from years of moisture. The rubber mallet trick works but I've also had luck with a small propane torch on the really stubborn ones, just gotta be extra careful not to overdo it. Last time I tried PB Blaster on a seized shaft I waited 45 minutes and still had to break out the heat anyway.
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smith.nancy1mo ago
Gotta disagree slightly @sean_green44 on the wet rag thing. In my experience, the sudden cold from the rag can cause the shaft to warp just enough to make things worse, especially on older motors where the metal is already fatigued. I'd rather take my time with the heat gun and keep the torch as a last resort since one slip and you're buying a whole new fan assembly.
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