MES 40 Overheat - FIXED

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Fire Starter
Original poster
Oct 5, 2013
Hot Springs, Arkansas
My two year old MES 40 with window and remote suddenly started overheating to the point that it would burn anything in it and had a bad smell of hot electrical/oil.  Upon checking it I discovered the element was on any time the cord was plugged in.  That condition even occurred with the top control disconnected! I called a MES parts supplier and was told it was probably the control on the top.  I know better than that.  The tiny little control wires couldn't power that heating element so somewhere burried in that thing had to be a relay!   DaveOmak was kind enough to send me a simple wiring diagram and point out that there was an electrical box under the bottom.  The wiring diagram indicated a relay that connected the heating element to 110 volt power input.

I had already checked the back of the unit for the box there and the wiring for the element appeared OK so I got out my trusty drill and removed the cover on the box on the bottom.  Sure enough, this is what I found.

At the lower left of the box is a relay.  It is a Hongfa HF2160-1A-12DE which is a common Chinese 30 amp control relay.  Since such is not available at the local Radio Shack I got on the internet and found you can get these things from a variety of suppliers on E-Bay and other on line locations.  I even found some for as little as $0.45 plus shipping (from China of course).  Since I did not want to wait 4 to 6 weeks for delivery I ordered five of them (minimum order) from Future Electronics in Canada. They charged me about $2.50 each plus $9.00 FedX shipping. I figured at a bit over 20 bucks it was cheap to avoid having to replace a $300 smoker. They drop shipped the relays from Mississippi and I got them in only two days! 

In the bottom of that box is a printed circuit board that is glued in place with white silicone rubber.  I cut around the edges and carefully pulled the PCB out of the box.

They definitely did not want you to fix these things as the whole board is covered in silicone and sealed in there. I took out a knife and carefully removed the silicone from the board where the relay is located and cleaned the 4 soldered connections on the back side of the board.  I then used my soldering iron and desoldered the 4 connections and removed the old relay. 

You can see the old relay with its four pins on the back that goes into the PCB.  It was then a simple job to replace that with the new relay and solder the 4 connections back.  Have to be careful as there are a number of other connections that are not under that relay.  I then recovered the PCB on both sides with white silicone that I got from a local Lowes store, stuffed it back in the box and pulled out my picture that I took when I opened it to make sure all wires went back into the same locations as original.  This is the picture of the repaired circuit board back into the smoker.

I used plenty silicone as that both holds the board in place and is the only protection the sensitive electronics on that board have from the grunge that is found around a smoker.  This is the picture of the replaced board.  A quick check verified that the heating element no longer came on when the unit was plugged in so I finished reassembling the smoker and set it to heat for a few minutes to 110 degrees.  It worked!  I then put water in the pan set it for 225 for an hour and put a bit of chips in the smoke pan to check it out and re-season the unit.  Everything was fine just like before the problem came up. 

Many thanks to DaveOmak for his help.  I am now back up and running.  Have 20 lbs of chicken legs to go into it tomorrow!  Needed that to take to deer camp on Saturday.  Also have a pig trap at the camp and hope to catch one to smoke and make sausage.

Speaking of deer camp, anyone have a good recipe for smoking coons?  We have them everywhere around the camp and I am going to have to harvest some of them just so I can keep my pig trap baited.  They clean it out and I have nothing left to attract pigs if I don't.



SMF Hall of Fame Pitmaster
OTBS Member
★ Lifetime Premier ★
Nov 12, 2010
Chuck, evening.....  Nice fix and very good tutorial on repairing the MES 40..... Several folks have had your problem or a similar one...   We'll have to keep you and this thread around to help others.....     Did I mention great job.....      Dave



Bob R

Mar 13, 2021
I realize that this is an older posting....but I had to thank you none the less!
This seems to be my exact problem. Following your lead here should make it an easy fix!
Thanks again if you are still out there! is reader supported and as an Amazon Associate, we may earn commissions from qualifying purchases.

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