Masterbuilt Smoker Not Working

[KJNDIVER]

So, which is more likely? Did the safety switch do its job, meaning I had an over heat condition? Or is this just a compromised inexpensive part that just periodically requires replacement? I dont think i have ever used the unit wide open except for the first firing to season the inside. I almost always smoke in the 225-250 range. The safety switch, is it a one and done piece of equipment? Meaning if it were an actual overheat situation, would it do its job and then would require replacement? Or would it reset and continue to perform its functions? Just curious.

 

[bill1]

So, which is more likely? Did the safety switch do its job, meaning I had an over heat condition? Or is this just a compromised inexpensive part that just periodically requires replacement? I dont think i have ever used the unit wide open except for the first firing to season the inside. I almost always smoke in the 225-250 range. The safety switch, is it a one and done piece of equipment? Meaning if it were an actual overheat situation, would it do its job and then would require replacement? Or would it reset and continue to perform its functions? Just curious.

That style switch is bimetallic based...if you remember the old "automatic chokes" on carburetors (typically a heater hose was ran past it) it works the same way...two laminated metal strips expand at different rates with temperature so they actually move (to open an electrical contact or rotate a choke plate) when heat is applied. They have an "action" temperature (the 150C=300F) at which a "normally closed" (conducting) switch will open (to prevent further heating of an in-line element) and then a reset temperature, typically 30F lower, where the NC switch, which opened, becomes closed again. It can be used again, but not hundreds of times so they should be a protective backup to a separate thermostat system, not front-line defense, even if a ~30F temp control range seems adequate to you. If they don't reset by room temp (an NC model that reads open) they're broken...if you shake and tap them, they may become conductive again but that's kinds of dangerous...they may not then open again in their normal manner.

I believe their primary failure mechanism is corrosion--they tend to have steel parts like pivot pins etc inside, that just rust away. If they look pretty bad, replace them. As with most switches, you want "bright and shiny". Granted the outside appearance isn't what counts but that's all you have to go by.

 

[tallbm]

Not sure what the difference is between the one you recomended and the one that i had already ordered. Appear similar, but appearances can be deceiving. Will do on the cutout, I was already thinking the same thing. I have ordered the connectors as well. May not change right away, but will have on hand for when needed.

The ones u ordered will not work.

Look closely at the image of the ones I posted. The button sensor and the fastening plate are all 1 piece of metal.
The ones you posted are 2 pieces of metal where the fastening plate moves. It is not fixed the button sensor. I made the same mistake once in the as as well so if you can cancel your order and change it for the one I posted you can maybe safe yourself some grief.

There is just no sensible way to make the ones you posted work because the 2 pieces float/move from one another leaving a gap that smoke will absolutely get through and no way for your sensor to stay fixed and pushed all the way forward into the smoker interior.

 

[tallbm]

So, which is more likely? Did the safety switch do its job, meaning I had an over heat condition? Or is this just a compromised inexpensive part that just periodically requires replacement? I dont think i have ever used the unit wide open except for the first firing to season the inside. I almost always smoke in the 225-250 range. The safety switch, is it a one and done piece of equipment? Meaning if it were an actual overheat situation, would it do its job and then would require replacement? Or would it reset and continue to perform its functions? Just curious.

Those safety rollout limit switches are auot reset so if they trip they will go back to close after they cool down. They are also just cheap and delicate causing them to fail easily on you. I would bet $10 it just failed due to whatever caused so much rust on it... I've had a number fail on me.
They usually fail because the corroding connectors stop connecting well leading to overheating at the tab which melts and/or damages the switch. Yours looks rusted so that would be my guess.

ALSO IMPORTANT, when you put new connectors on these stupid switches if you WIGGLE the tabs at all you can expect the switch to melt down at some point in the future. A ceramic one would be better but is harder to find.
Again these switches are delicate.

The easiest way I've found to work with them is to add the connectors on each tab just to where they push on somewhat but not all the way.

Then hold the switch on a block of wood standing up on one of these connects and tap the top connector downwards with a small hammer. This will make the top or bottom connector slide down in the completely installed position you want.
Rotate to the other connector and repeat. Do this until both connectors are on the tabs and you wont have wiggled, bent, rotated, etc. the tabs at the base where they connect to the back of the switch.

NOW, you put the wire into the connectors and crimp.
FINALLY, you fasten the thing to the smoker.

If you do it like that and in that order you wont wiggle the tabs at all which causes the switch to melt down on you after sometime. It took me a while to figure out what was causing my switches to keep melting... It was the fact that they were delicate, cheap, and any wiggling somehow compromises the switch so it melts after a while.

 

[KJNDIVER]

Good to know. Thanks for the info everyone.

 

[bill1]

Here's a little more info on the internals of these switches.

https://www.calcoelectric.com/images/pdfs_thermostats/calco_ksd301series.pdf

 

[dernektambura]

Then the question becomes, what symptoms or measurements have you done since then? If you haven't installed it yet, we'll assume you might want to get a refund so lots of folks (e.g. Dernek) more knowledgeable about this unit than I can help you trouble-shoot it.

Man, you're giving me to much credit... I don't own plug and play type smoker... it's just that all smokers electrical design is pretty much same and easiest way to troubleshoot is to start disconnecting from end (heater and measure voltage....
Electrical design of smokers is based on idea:
in order to enter next room ( walk out of the room you're in ) you must make sure previous door (door you walked in that room) stays closed.... in other words: for electricity to flow freely gates need to be closed...

 

[KJNDIVER]

Well.......back to the drawing board. Ordered the replacement parts. They came in a few days ago. Was sitting around on this fine Christmas day and decided to put the smoker back together. Got all the parts installed, put new screws in place of rivets on back panel, tightened and adjusted everything inside. Plugged her in, turned her on and she warms up like the prom queen in backseat of car. Put some chips in the tray and turned it on wide open to 275 to burn some of the funk out of it from sitting around a while. Temp climbed to 180 and it was just starting to smoke so i walked away for bit to do something else. When i come back the temp was 150. Waited around a bit and it just kept dropping lower and lower. When it got down to 130 i just unplugged it and said Ill have to trouble shoot it another day as Im about to go somewhere for another round of holiday groceries at my parents house. So now Im right back where i started from. Everything appears to be in working order, but she no workie. The roll out switch will now be my first place to look since that is the part that was changed. Good thing you can buy em 5 at a time, but dang, you would think it would have lasted longer than 20 min.

 

[tallbm]

Well.......back to the drawing board. Ordered the replacement parts. They came in a few days ago. Was sitting around on this fine Christmas day and decided to put the smoker back together. Got all the parts installed, put new screws in place of rivets on back panel, tightened and adjusted everything inside. Plugged her in, turned her on and she warms up like the prom queen in backseat of car. Put some chips in the tray and turned it on wide open to 275 to burn some of the funk out of it from sitting around a while. Temp climbed to 180 and it was just starting to smoke so i walked away for bit to do something else. When i come back the temp was 150. Waited around a bit and it just kept dropping lower and lower. When it got down to 130 i just unplugged it and said Ill have to trouble shoot it another day as Im about to go somewhere for another round of holiday groceries at my parents house. So now Im right back where i started from. Everything appears to be in working order, but she no workie. The roll out switch will now be my first place to look since that is the part that was changed. Good thing you can buy em 5 at a time, but dang, you would think it would have lasted longer than 20 min.

Switch is my guess. Those things are super delicate. If you wiggle, bend, or cause any movement of the tab where it meats the back of the switch then it will fail on you at some point... sooner or later. Sounds like in this case maybe sooner.

You can always just wire nut those wires around the rollout switch to limp through a smoke.
If you can find the ceramic backed switches then it may be more durable but I'm just guessing since I'm still burning up my plastic backed ones hahaha and wire nut around when it happens. heck I think I'm wired around atm, might have to check.

 

[mosparky]

When it's dropping temp when it should be heating, check voltage across the roll out. Zero volts working and not the problem. 120 VAC open switch and theres your problem.

 

[bill1]

Did you replace that "roll out switch" at mid-height in the unit? I suspect a lot of these things get mislabeled/confused throughout the distribution chains and getting a lower or higher opening temp than you ordered is quite common. Paying more and using well-respected distributors (instead of Amazon) helps the last step in the chain but it can be pretty convoluted in the first dozen steps of these Chinese-sourced products and even the best US distributors are pretty powerless to control that.

Also, some vendors will knowingly send you the wrong thing if they're out of stock on the right thing just so they can take credit for the sale in that fiscal month with full knowledge they're going to have to go through the hassle of a no-cost replacement later on.

And I shouldn't blame on malice that which can be explained by incompetence. In other words, worldwide Covid and seasonal hiring patterns mean a lot of inexperienced (or unguided) people are in the labor pool now so errors like confusing opening and reset temps, 1.8 conversions from F to C occurring twice, etc etc are happening more frequently.

 

[KJNDIVER]

Well, I got both orders delivered, the 2 piece that inadvertently ordered and the one piece design. I see what you mean now. Yea, the one piece is a "better" design. I suspect you may be right Bill, as I have turned the unit back on without touching anything and watched closely, it heats up to about 183-184 and then it shuts off. I've done this 3 times now. So I suspect that either the dang thing is damaged or its not actually the one I need. I never inspected after receiving the order, just installed it. I'm at the deer camp this week, ill have to look into it further when I return.

 

[bill1]

Well there may not be anything to look at. A lot of these are just stamped KSD301 with the V and I rating. A few will give the temp in C that they open up at but not all. So you can imagine how hard it is to properly stock a part like that. Sounds like you got an 80 or 85C model. It works fine, just not at the temp you wanted.

It's hard to imagine anyone wanting one opening at this low a temp so they're probably the last ones to sell out! Even if all you're protecting is low-temp plastics, 180F=80C seems kinda' worthless. Although I guess that's the threshold for getting a surface skin burn so if you want to keep an external surface from burning someone you might want an 80C switch. So I guess nothing's truly worthless. All God's children got a place in the choir.

Here's a choir of them that open at 80C and below. At least they're stamped with the temp:

 

[KJNDIVER]

Ok....upon further investigation... it is indeed as bill suggests.... i have the wrong item installed. I pulled out my glasses so my old eyes could see better and the parts are stamped with all the info except for the temp rating. So that was no help. I go back and look at my order from amazon, go back to the page... THEN i see that there are options for different products and different temps. Apparently I had inadvertently clicked on one of the other lower temp items and not noticed it. I look at my order and get info, compare that to the different items offered, and i did indeed order one for only 80*C and not the 150* one. So i pull out the bag for the other order i had made, the one with the two part item. It is stamped for the 150*C. I hook it up and immediately notice how the two part item will not be a good solution long term. Just a mess. But hooked everything up, put it all back together and she works just like new. Took 10 min to heat up to the 180*F on the controller, then went on thru to 275*F in the next 10 min. When it got to the max setting of 275 i heard the relay kick out and the light on panel went off. I opened the door, the temps fell, but the relay did not kick back in until 260*F. Took a few minutes, but started climbing again. It went all the way to 275 again and kicked out. But the temp kept rising on thru up to 283*F. I watched for a few cycles and as its cooling the relay kicks in and light comes on at 273 but the temps keep falling to 267 (door closed). It heats up, cuts out at 275 but temps keep going to 284. As its cooling it kicks in at 273 but the "momentum" keeps going to 268 before climbing again and then on thru the high side again to 284. Thats a pretty wild temp swing for trying to regulate at 275. Oh well, i dont use it at those temps and then i suppose thats why some of you guys have installed the other style controllers to better regulate the temps in a more stable range. I guess thats just the system that MB supplies. For most folks i guess its good. Anyway, i wanted to come back and say thanks again for all the help and pointers along the way..... i foresee some smoked meat again in my near future. Thanks again guys, i appreciate it.

 

[bill1]

So you're saying with the controller set to 180F it barrels on through until something trips at 275? 275 is close enough to 300F (150C) that I think you're just opening and closing the switch you just replaced. That is not the way the thing was designed to control temp.

Why do you say "heard the relay kick out"? Are you sure you're hearing the actual black plastic electromechanical relay on the bottom board? Those "roll-out" bimetallic switches that you just replaced makes a similar switching sound. Like Dernek says, the electromechanical relays fail frequently. Luckily the pics you posted show you have one of the models where that power board comes out easily. MB normally stocks that entire board for $37 but they're out of stock now.

You've shown impressive skills so far...want to try some troubleshooting or even soldering? I'm pretty sure that relay is a Hongfa HF2160-1A-12DE. On the back side of the board you'll see two pins close together and two others further apart that are redundant with the connectors on top. The two pins close together are the 12VDC coil control signal. The trouble-shooting involves operating the unit with that board out so you can get a dc voltmeter onto those two pins. You may have to lay the unit on it's back. And you'll want to cover over all the rest of the board with plastic and/or electrical tape before you plug in the power cord so only the relay control (coil) pins are exposed so you don't get shocked. You should read 12V as the thing warms up to your 180F setpoint. Then it should go to near zero and the temp should stabilize. If it goes to 0Vdc but the temp keeps rising, the relay is bad. If it stays at 12V, the relay is doing its job and your problem is upstream in the controller.

If you need a new relay, or you just think it's worth replacing instead of trouble-shooting, you can get two of them for $11 with 1 week delivery from a US distributor or for $6 direct from the East with 1 month delivery. Here's some links:
https://www.ebay.com/itm/2pcs-12V-HF2160-1A-12DE-4pins-30A-240VAC-Relay/291748837318
https://www.ebay.com/itm/US-Stock-2pcs-12V-HF2160-1A-12DE-4-Pins-30A-240VAC-Relay/401553055755
Note this requires some simple soldering and you'll want some solder wick to get the old one out.

Please verify the relay P/N is what I think before you order anything. The datasheet for this relay is at:

https://datasheet.octopart.com/HF2160-1A-12DE%28257%29-Hongfa-datasheet-12557546.pdf

 

[KJNDIVER]

No, thats not what I was intending to say. The unit was set to 275*F as I stated that i wanted to burn out some funk inside the box. I mention the 180*F only so much as that was the sticking point that I was reaching with the previous (incorrect) switch. Thats all. The unit works as intended. And yes as mentioned in my initial post I am hearing the relay kick in and out on the bottom of the unit. It is the relay as whenever i hear the sound the light on the dashboard indicating burner is hot also comes on at exact same time. I do not hear the sound at any other times. I think i can pass on that troubleshooting for now, as I dont feel theres a need. But Ill keep that in mind if I come to that bridge. Thanks.

 

[bill1]

Sounds like you have a fully functioning unit then. Great news, just sorry I was slow to understand that.