Repairing My Electric Dryer and a Little Math

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I came home the other night and my wife reported that our clothes dryer was not generating any heat for drying clothes. I had heard a few people having the same issue of the dryer not heating so I did some research for myself. She called a repairman and he could not repair our dryer for a long time and was going to charge a lot of money (e.g. $90 for a heater coil that was $30 from Amazon). There was no way we could have waited, so I decided to create the beste wasdroger for her with my handyman skills.

While I know NOTHING about clothes dryers, I decided to try to fix it myself. I'll give you folks a statutory warning! If you don't have any prior experience, you could seek professional help like, which specializes in providing electrical services and repairs. Now coming back to my story, as with most of my repair adventures, I started with Youtube. After a couple of minutes, I found the following video where a repairman gave a great demonstration on how to change the heater coil (Whirlpool part number 3387747) in my clothes dryer.

Unfortunately, this video did not tell me how to test the dryer's heater coil -- from the schematic, it seems like a failed thermostat or thermal cutoff would also result in no heat. I decided to measure the resistance of the coil in my dryer and I discovered that the coil was open -- my heater coil had failed.

While the coil was open and clearly failed, I became curious as to what value the coil resistance needed to be. The manual for my dryer does not give me the required coil resistance, but I was able to estimate what the coil resistance should be using Equation 1 -- the formula for the power dissipated in a resistor. The only information I needed were the wattage and voltage ratings of the coil, which were stamped on its side.

Eq. 1 \displaystyle {{P}_{Coil}}=\frac{V_{AC}^{2}}{{{R}_{Coil}}}\Rightarrow {{R}_{Coil}}=\frac{V_{AC}^{2}}{{{P}_{Coil}}}=\frac{{{\left( 240\text{ V} \right)}^{2}}}{5400\text{ W}}=10.7\Omega

Figure 1 shows my failed heater coil. I found the break in the coil right away (marked in red and pulled up).

Figure 1: My Broken Heater Element. I have bent the break to make it more obvious.

Figure 1: My Broken Heater Element. I have bent the break to make it more obvious.

I ordered a new coil from Amazon and it had a resistance of 9.9 ?. My rough analysis in Equation 1 was pretty close. I also measured the resistance of my old coil (after connecting the broken pieces back together) and got 11.5 ?.

I later found another heater coil repair video that discussed how to test the heater coil. I have included this video below. This was a lifesaver! And I have since thought about getting added protection for my clothes dryer and all of my other appliances in the form of a home warranty plan (check it out here) so I don't have to worry about doing any repairs again in the future. Whilst I managed to do it successfully this time (I think), I'm not sure if I will have the same luck in the future, so it's better to have a back-up option in case anything were to go wrong.

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