St Croix Hastings Room Fan Stays On

My stove is close to 20 years old. The last month or so I noticed it took a longer than normal time for the room fan to stop after the stove was shut down. This morning it was still running after being shut down 12 hours ago. I unplugged it, hoping for some kind of reset. Plugged it back in and the room fan started up and the stove started itself. Ideas?

 

Does the Hastings use a snap disk to trigger the blower to turn on? That snap disk may be sticking. My Castille (about the same age as your stove) is occasionally running for an extra 10-20 minutes or so. I need to get another 125°F snap disk.

 

I like that answer...sounds like a cheap fix! I had fears of control board issues. Thanks!

 

Plus one. Most units will have a high limit snap disc and a low limit disc and the low limit snap disc also tells the board to shut off the fan. You can buy them from any online stove part dealer, just be sure to get one than matches your cut out temp, which should be stamped on the body of the disc.

I'd probably (considering the age of the unit), replace all of them. They do wear out after a few thousand cycles.

 

There is a very slim chance (but I don't believe so) that the room air fan Triac is faulty. You need to renew the snap discs first and if that don't cure the issue, then PM me or post up a comment and I'll explain on how to replace a Triac. Triacs control all the motor functions on any stove. They are soldered into the board and if you are good with a pencil soldering iron, you can replace them, but like I said, if the snap discs don't cure it, we can get into them. Readily available from DigiKey or Dell Electronics and they are cheap. Basically, what a Triac does is chop the ac current to the motor to adjust the armature speed. All your motors are synchronous so the only way to vary the rpm is chop the current. Your IC chip 'tells' the Triac when to turn on and turn off. Pretty simple really.

Finally, I hope you have your unit plugged into a quality surge suppressor. Boards are expensive, surge suppressors are cheap insurance. I recommend a Tripp-Lite Isobar myself. Amazon has them for like 30 bucks shipped. All I use on the stoves and my computers too.

 

There were 3(at least ( different control board setups for the old St Croix's, but I believe yours is new enough to not be the first series, and is a digital board. No snap switch. But stove should not start itself unless it had input from you,on the board or a T-Stat. You most likely need a new board. IF yours does not need a conversion/upgrade, the boards are pretty cheap,now. If you have any doubts as to which one,call ESES, they are probably the best for info on the older St Croix's.

 

Never seen any stove without a high limit and low limit snap disc. Something mechanical has to tell the board what to do to deactivate the corresponding Triac. Maybe they exist bit never seen one.

 

I see a reset high limit thermodisc, and a high fan override switch, on a stove parts web site for my stove, but nothing about a low limit disc.

 

order accordingly then. Again, not familiar with your unit. If that don't fix it, I'd say you have a bad Triac.

 

Thanks for the input guys! This is why I've been hanging around here for so long!

 

OK

after researching the manuals, if yours is a digital control board (analog controls may have a different one), they use the proof of fire switch to also run the convection fan, through the programming. it is - Part # 80P20038-R

 

If it is the board, no point in buying a new one when, if you can handle a pencil soldering iron, you can replace the Triac. Last time I checked on DigiKey they were about 10 bucks a dozen.

 

So the high limit thermodisc has a reset button. I pressed it, and the stove shut down properly. Maybe just a fluke, maybe a temporary fix, but for now I'll take it! Thanks again everybody. Sometimes just throwing a question out there is enough to motivate me to actually take the back off the stove and poke around.

 

Some do, some don't (reset snap disc) If I was to replace mine, I'd go with the resettable ones. They cost a bit more but are worth it.

 

All that is in a thermodisc is a flat piece of round sheet metal that reacts to heat and 'warps' one way or the other. If I were you, I'd order a spare now while it's still working because that metal will fatigue after many hundreds of cycles.

 

So I replaced the high temp thermo reset disc. I like saying that cuz it sounds like a bigger deal than it is! Anyway, I ran through a cycle, and it shut down correctly. Not positive proof yet, because shut down came and went. Also got a new burn pot, cleaned the glass... tonight a cold beer or two, letting the stove do its thing...

 

Hopefully that was the fix! How'd it run last night and today?

 

It's been running on 2 (out of 5), steady for a couple days. The basement stays at 70, and the house stays comfortable. I burn a little oil upstairs just to take the chill out of the corners. I just retired from meat cutting after 40 something years, and I'll be dammed if I'm gonna be cold at home! I just shut the stove off an hour ago to give it a quick clean. The fans are still running, and it's still warm to the touch. Hopefully it shuts down in the next half hour or so.

 

Sooo, I gave it three hours and the fans were still running. It was cold to the touch, the air coming out cold. I held the start button and it started back up normally. Not sure what's next, but at least it's doing what I need it to do now.