PT-422 Fan Temperature Switch

Vacuous_One · Jul 27, 2010

Anybody out there have a picture (or, would be willing to take a picture) of the top of the fan temperature switch that shows the text/numbers on it?

Mine's gone missing (the top of the switch, that is) and I want to replace it. While I could go directly to P/T, I've found their spare parts for pass-through items (i.e., "no value added") to be quite high! I'd like to bypass the middle-man on the commodity items, here. But, I need the info to get the right part. So, any help out there?

I searched the forums and found only a few references to this switch. "Woodlandfarms" had a posting ("What is this") where the first photo was of the switch, but it was from the side and I can't read the text.

Thanks for any help anyone can provide.

BobRip · Jul 27, 2010

Not the best picture, but it's something. I believe this is a clothes dryer temperature switch, but it closes when it gets hot.

Bob Ripley

frischtr · Jul 27, 2010

Here is a shot of the text (from a 425):

3238dpw · Jul 27, 2010

Does anyone seem to have any trouble with these. I replaced mine 3 times. It would go about every tank full. Then i got tired of that and just hot wired it so the fan was always on. Any thoughts from anyone would be appreciated.

BobRip · Jul 27, 2010

3238dpw said:
Does anyone seem to have any trouble with these. I replaced mine 3 times. It would go about every tank full. Then i got tired of that and just hot wired it so the fan was always on. Any thoughts from anyone would be appreciated.

I replaced mine once in 850 hours. Can you check your fan current? Maybe something is wrong with it. It should pull about 5 amps. Maybe it's not the switch. Did you check to see if the switch closed when hot? Could be a loose connection. Check you spade lugs and see if they are loose where crimped.

SpringHollow · Jul 27, 2010

On my PT 1850, i found cleaning the contacts resurrected it.

Ken

Vacuous_One · Jul 28, 2010

BobRip & frischtr:

That identifies it...White-Rodgers Therm-O-Disc Snap Action Fan Control switch, Series 60T, model 3F01-120. Closes at 120F, opens at 110F.

Now, to get one and do the replacement!

Thanks so much for your gracious help!

MossRoad · Jul 29, 2010

3238dpw said:
Does anyone seem to have any trouble with these. I replaced mine 3 times. It would go about every tank full. Then i got tired of that and just hot wired it so the fan was always on. Any thoughts from anyone would be appreciated.

Mine stopped working about 350 hours. I also hot wired it so it is always on.

RegL · Jul 30, 2010

MossRoad said:
Mine stopped working about 350 hours. I also hot wired it so it is always on.

I went through 2 than hot wired it on in Summer and off in Winter. I plan to wire in a toggle switch some day.

BobRip · Jul 30, 2010

I talked to the manufacturer of the switch today. The switch being used is not rated for DC. They do have a switch rated for DC, but only one amp. The fan pulls about 5 amps. I would recommend that if you care, put in a relay that is driven by the switch. The relay then controls the fan. I am at 850 hours and have replaced the switch once. I would say that's not too bad. I will continue to replace it. It does not cycle much so it does not wear out too quickly.

I think it is probably not good to cool the system in cold weather. It would increase the warm up time. With a switch, I guarantee that I will forget to turn it on during at least one hot day, and probably many. I don't see how this increases the PT life. As such, I will keep replacing the switch. I guess I am due.