Building a Smoker - How to Add a Thermostat?

Discussion in 'Smoker Builds' started by sweeby, Oct 2, 2009.

  1. sweeby

    sweeby Newbie

    After trying out a friends Masterbuilt electric smoker, Hubby and I fell in love with home-smoked meat (wild boar and wild duck!) and decided to buy our own smoker. Hubby's the builder; I'm the researcher.

    So I researched, then dragged him out to Bass Pro Shops to see what was available. We both concluded that we wanted a sturdier insulated box in stainless steel (inside and out) with simple replaceable mechanicals. But of course, we didn't want to spend the kind of money that seemed to cost. Hence the DIY. What we have so far is this:

    Box - A stainless steel commercial 'cook & hold' oven, same model as this one. It's in great structural and cosmetic shape, but the electrical bits were shot.

    Heating elements - A stainless 110V commercial two-burner hot plate similar to this one. One burner is 1250 watts, the other 1800 watts, which should be ample, I think, given the oven's insulation. We figure the electric coils would be easy to replace down the road.

    Hubby is mounting the hot plate inside the box, and re-wiring the temperature-adjustment knobs, on/off switches and indicator lights to a new faceplate (replacing the ugly orange one) We're not anticipating any problems with that part.

    But what we'd really like to do is add a thermostat to control the heat.
    I've heard it's possible. I've read where people have done it.
    But NOWHERE can I find HOW to do it!
    The only online directions I can find basically say to insert the temperature probe, then wire in the new thermostat the same way the old thermostat was wired! And we can't do that, since the old thermostats and heating elements presumably didn't work and were 220V anyway.

    So my real questions are these:
    1) I see lots of simple-looking oven thermostats on ebay. (Is that what we need?)

    and 2) HOW can we wire in a thermostat to control one set of the hotplate's coils?

  2. bbq engineer

    bbq engineer Master of the Pit OTBS Member SMF Premier Member

    You might want to check out a PID controller with a thermocouple to monitor the temperature. This in turn triggers a contactor to supply current to your heat source. Check out Auber instruments or ebay...

    I have been wanting to get a PID setup that triggers a blower when below temp for a poor man's version of a BBQ Guru. More than anything just to experiment with.
  3. Here is a pic of my PID controlers, bottom is ramp/soak type for smoker temp control and the upper is for meat temp. Upper turns everything off when meat reaches desired temp.
  4. bearcarver

    bearcarver Smoking Guru OTBS Member

  5. sweeby

    sweeby Newbie

    If they're as simple as they look, those PID controllers look fabulous!
    Is it really as simple as:

    1) Plug electricity into PID controller
    2) Plug heating element into PID
    3) Connect sensor
    4) Set the desired temperature

    Is that it? Please tell me that's all, because I'm holding my breath!
  6. bbq engineer

    bbq engineer Master of the Pit OTBS Member SMF Premier Member


    You are close....Since the output of the one I looked at is 3A at 240 V, it will not handle the current demand that your heating elements require. Therefore, you will need to use a contactor that is rated for much more current. So, I would connect the output of the PID to the solenoid input of a contactor (relay). That way the PID is controlling the contactor, and the contactor is supplying the current to the heating element.
  7. sweeby

    sweeby Newbie

    Thought you might enjoy pictures of our new baby:
  8. I have been thinking about the thermostat issue myself for a while as I am planing a fridge conversion if I can find the fridge. I think just about any accurate thermostat with an external probe could be used so long as you couple it with a suitable relay to activate the heating coils.

    Does this set off any flawed logic alarms with anyone?
  9. nickelmore

    nickelmore Smoking Fanatic

    That is sweet looking, where did you get your heat plate and how much do you have into it so far?

    When I built mine I didnt want to tie up alot of money in something I did not know if I would like or not. By the time I was done I had more money in it then I could have bought one for.

    But there is some kind of pride when you can say "yes I built it"

    I am looking for a electric heating element so I can use my box as a "hybred" a gasser when I need and an electric on some long smokes.
  10. sweeby

    sweeby Newbie

    I'm with you on controlling your up-front investment until you know if you're going to like it or not.

    We've got about $225 into it so far. The oven box was $150 from the 'scrap pile' at a nearby restaurant supply warehouse, plus another $20 or so for racks and sheet pans and a few hours of elbow grease to clean off superficial rust and burnt-on grease. Add $6 for the sheet of steel Hubby used to make a new faceplate, $10 for the chip box, $15 for electrical supplies Hubby used to rewire with. The hot plate is one I bought on ebay for $35 four years ago when we renovated our kitchen. It's clearly much more powerful than we need...

    We did a small test run last night, and were able to hold a steady 225 degrees using one burner on a 4 (out of 10) power setting -- so if we can rig in a good oven thermometer, we may not the PID after all -- which would be nice. Checking on the temperature and smoke status is part of the fun after all --
  11. gruelurks

    gruelurks Smoking Fanatic

    Pretty sweet looking DIY project so far, looking forward to seeing some Q out of it.
  12. sweeby

    sweeby Newbie

    Thanks GrueLurks --
    When somebody's as talented as Hubby is, calling it 'DIY' just doesn't seem to fit ;-)

    I'll post rib pictures tonight if all goes well...
  13. nickelmore

    nickelmore Smoking Fanatic

    I think I will stop by a used restraunt supply house to see if I can score a hot plate. The guys around me tend to think everything is gold and almost priced as new.

    We can see that your handy with a camera, after seasoning lets see some Qview.
  14. sweeby

    sweeby Newbie

    For what it's worth, the used commercial hot plates at the restaurant supply warehouse (where we got the box) were priced at about $70-150 range, and I think most were designed to run on 220V. Plus, they may be much more powerful than you need... Ours can get the box temp up 100 degrees in just 15 minutes or so. Though I have to admit, that's nice to get the chips smoking and reheat the box after opening the door.

    You'd probably be fine with a Walmart cheapie or a decent single from ebay.
  15. I had a pid hooked up to a 110 electric element to try out. what i found was that it was ok at best during the summer months. but when we got our ohio winter and loaded down with butts it did not work. it might reach 225 but the recovery times were very slow after you opened and closed door and meat cooked to slow.i immediatley converted it back to propane with pid and a old 24v propane furnace valve. i used a type j thermocouple back to pid and it works very good. just my 2 cents worth.
  16. nickelmore

    nickelmore Smoking Fanatic

    I was wondering about that, so you have a elictric pilot or a constant pilot? Any pictures, I do like the quick ramp up time and recovery of gas.

    I have not seen any other threads with something like this, if there is I hope someone points me to them.

  17. sweeby

    sweeby Newbie

    Ours is all electric Nicklemore -- a more powerful than typical 110V two-burner hotplate.
  18. mulepackin

    mulepackin Master of the Pit OTBS Member SMF Premier Member

    I went with one from AlliedKenco and haqve been very happy with it. Truly plug and play. I'd post a pic of mine but I'm not on my computer.
  19. vinman

    vinman Newbie

    Man that thing looks sweet! I'm already getting tired of mine and I just got it! lol
  20. Start by getting your hands on an electric OVEN t.stat and get it mounted to only the temp probe is inside your smoker.  I suggest you put the t.stat in a metal outlet box with a cover.

    >>>>>BE SURE<<<<< the power cord IS NOT plugged in<<<<<<

    Next, the t.stat will have 2 screws for wire

    the power cord to the hot plate will have 2 wires ( and a ground)

    >>carefully<<  "split" the two wires apart from each other

    now cut one wire

    one end of the cut wire will go to one screw on the t. stat

    the other screw on the t.stat will have a wire that goes to the other wire on the power cord

    now with the knob that came with the oven t. stat you can set the temp you want

    or if you want only one temp, say you want to cook at only 350, then before you mount the oven t.stat. put its temp probe in your oven and set it to 350 or what ever temp you want, when your home oven says it is up to the temp you set it at, move the control on the t.stat you ordered and turn it till it clicks open.  You have just set the t.stat you ordered to the temp you have your oven set at

    >>>>>  BE SURE ! ! ! !<<<  you have your wire splices well covered with electrical tape

    >>>>>NEVER ! ! ! TOUCH a bare wire<<<<<< ! ! ! ! !

    >>>>> you will may be working with  live120 volts AC, work with one hand in your pocket

    I AM NOT and WILL NOT be responsible

    just telling you how I did it

Share This Page