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Discussion Starter · #41 ·
Corday, thanks for returning this thread to the original topic. There must be a way I can test the various parts to determine which one or ones might be defective. I can't see replacing them all and just hoping for the best.
 

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I understand there are many companies that primarily focus on their bottom line, but there are challenges with engineers in general, also. My son is responsible for all software development for all spacecraft designed, or already in space, for the major aerospace corporation he works for. He finds it challenging when he assigns an engineer to a project, only to find out the engineer chooses to take the easy way out and manipulate what already exists rather than designing something ideal for the situation. He often has to fix what engineers chose to just jury rig.
 

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I designed my home to be convenient, very much unlike engineers who design for their own convenience and don't consider the end-user. For instance, who in their right mind believes the most convenient place to locate a vehicle fuel pump and filter is inside the gas tank?
Since the laundry is on the second floor, running the vent down to the first floor would involve a number of bends in the pipe, not a really good idea with a dryer vent.
 

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Since the laundry is on the second floor, running the vent down to the first floor would involve a number of bends in the pipe, not a really good idea with a dryer vent.
https://en.wikipedia.org/wiki/Dryer_vent , click on "Spin Dryers" and note the kinked vent above the dryer, then the pic of the inside of the vent. (Fire Hazard)
 

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Discussion Starter · #47 ·
https://en.wikipedia.org/wiki/Dryer_vent , click on "Spin Dryers" and note the kinked vent above the dryer, then the pic of the inside of the vent. (Fire Hazard)
I used to do volunteer work for an agency that built homes for veterans. Their dryer vent design never made sense to me. The laundry hookups were in the garage. The vent went up into the ceiling and across the garage and out the wall opposite where the dryer was. The city required a blower half-way across the garage to make sure the lint was forced out of the house. My concern with this setup is no one will ever want to clean their vents, as there is no easy access or direct flow. That's 2 elbows and a fan between the dryer and the exit.

By the way, I'm still working to find the solution for my dryer, so any suggestions would be appreciated. I removed and cleaned the grill outlet, moisture sensor and blower fan and housing. There was a slight coating of dried lint, but nothing to cause any significant reduction of airflow. Resistance in the new (and old) thermistor lowers as the temperature rises, though overall range appears a little lower for the old one than the new one. Are there any other suggestions I could test? Since the thermostat is just high and not cycling, and it does shut down the dryer when it overheats, I don't sense that is the problem. Since I was able to run a load to completion and have the clothes dry, I sense none of the fuses are bad. I don't know how to test the pressure sensor.
 

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Discussion Starter · #52 ·
Each bend in the ductwork subtracts from the maximum length allowed. Here's the International Code on the subject: What is the maximum length for a clothes dryer vent?.
I understand this was the reason the city made them put in in-line boosters. Though the in-line boosters are supposed to be self-cleaning, you can't get a brush through it to clean the rest of the vent pipe, so I doubt these vent pipes will ever be cleaned... leading to an eventual fire condition.
 

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Discussion Starter · #53 ·



Thanks for the links, but they are for washing machines, not dryers. I have no idea the purpose of the pressure switches in dryers. Do they shut down the dryer if the lint screen gets filled and pressure builds? Do they activate aspects of the dryer when they sense normal pressure? Would a faulty pressure switch cause the dryer to overheat and shut down? This is the part: Kenmore Dryer Pressure Sensor 279580 3407033 ASMN | eBay
 

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Discussion Starter · #55 ·
It's only $20? Replace it.
I'm not going to replace a part when I have no idea what it's purpose is or how to test it. You could say to replace all parts of the dryer that cost $20 or less. That will add up to more than I bought the dryer for when it was new, yet I may still end up with the same problem. I'm looking to understand the problem, not replace parts that don't need to be replaced.
 

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And for each of those parts, you want us to teach you exactly what they do, how they work, and how to test them . . . in a 30 year old clothes dryer . . . and for free? Sorry man, but Nope, I'm out.
 

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Clearly, the pressure sensor would be for sensing back-pressure in the exhaust line, so it's certainly a possible suspect. I'm at a total loss where else a pressure sensor would be used in a dryer.
 

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Discussion Starter · #59 ·
Clearly, the pressure sensor would be for sensing back-pressure in the exhaust line, so it's certainly a possible suspect. I'm at a total loss where else a pressure sensor would be used in a dryer.
Thank you for your response. It sounds like you believe it would shut the dryer down if there is too much back pressure from lint buildup in the vent pipe. That makes sense, but I wonder what it might do if there is no back pressure but the sensor goes bad. I doubt it is causing my problem, but it can't hurt to test it anyway. I tried blowing through it, and air didn't go through. Maybe it needs a certain amount of pressure to send a signal to the burner. There is a hose from the blower housing to the sensor and then from the sensor to the burner assembly. I checked its two contacts for resistance and there is none. There are very few sensors in this dryer, so I figure I might as well test them all. (thermistor -- already replaced, high-limit thermostat, moisture sensor, radiant sensor and pressure sensor)
 

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I tried blowing through it, and air didn't go through. Maybe it needs a certain amount of pressure to send a signal to the burner.
You can't blow through a pressure sensor, this happens to be a topic I know a bit about. ;) In a previous life I designed avionics, including several air data computers.

The other port is for ambient pressure, not a pass-thru. The object of the exercise is to measure the difference between the ambient pressure and the pressure in the dryer exhaust vent. That's normally done with a strain gauge on a flexible diaphragm or a capacitive sensor.
 
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