How to recalibrate a Marcland Auto Draw Off?

[Bruce L]

Have had this unit for seven years now,found last year towards tail end of season that the syrup would sometimes come off a little light. Have been checking more often with hydrotherm than I should have to in order to get proper brix. The other day I gut a bucket of pure snow and stuck the probe in it,reading was 37.9 degrees,should have been closer to 32 I thought.Kept playing with temperature until I got it set at 225.6 for 67 brix,within 1/2 hour it was down to 225.1, at the start of the season I was running 219.6 and higher. I have contacted Marcland,but have not yet received any answer,has anyone else had to recalibrate their unit,and if so how?

[Haynes Forest Products]

Why are not calibrate it to boiling water then go up 7 ? Now I under the impression were working up from Your boiling point at your elevation not the freezing point of snow.

[Bricklayer]

What type of temp controller does the Unit use? Should either be on the front of the display somewhere or on a white sticker on the inside of it. Pretty sure marcland uses pretty standard PIDs for their units.
If your not getting close to 32 F with slushy snow , water mix. Then you might have to set the temp offset.
What do you get when you boil water at a good rolling boil and stick the probe in?
Also a loose connection wire from the probe will give a funky reading sometimes.
I have an auber auto drawoff made from their kit and at start of season my reading were way off. Went through the settings and found that it was set for a K- type thermocouple. Changed that and worked 100% better.
Might be something as simple as that

[Shaun]

I am not familiar with the marcland. You may want to check connections to ensure they are intact. If marcland uses a RTD probe a faulty connection might make a difference in your reading. I do not think you can calibrate most sensors used in these auto draws. I think a better word may be to "verify". A glass of ice water should read ~32 F after sitting for a few minutes.

[Bruce L]

Thanks to help on here,and speaking with Bruce Gilililan, I believe I may have rectified the issue. Had open house yesterday,so I had 600 gallons of water to boil,which would last less than 2 hours so I slowed the evaporator down ,which even with blower turned way down still boiled like crazy,but anyway only fired every 15 minutes,so I had time to play around. Looked at the wires on the Marcland,and as soon as I touched them temperature went crazy,looked like a series of w in the readout,high temperature alarm went off and shut the blowers down. I unplugged the Marcland,undid the wires and found the white wire only had one tiny thread of a wire. Cut all the wires of,restripped them,and reconnected,found the water to be boiling then at 212.9 ,which is quite possible since there was remnants of near syrup in the pan. Now just need to find small alligator clips for the wires,as I bring the Marcland home for the summer,and the wires need to be disconnected and then reconnected next spring,they are pretty fine for doing that very often

[Haynes Forest Products]

Get yourself some crimp on wire connectors and do it right. You don't want the clips to pop off at the wrong time. When the probe has a fault like when a wire comes off the PID will go flat line after it goes thru its start up sequence and then the over temp alarm will sound off. Strip the wires back and double them over in the crimp on even triple it to get a good connection.

[Bruce L]

Might still need a new probe. Boiled again today,straight water,boiling point was 210.9 , will check against digital thermometer here at home unless there is a way to adjust the Marcland

[Bricklayer]

It's a generic PID controller with Marcland stamped on it. No different then the CDL, Smokey lake ones. You should be able to get into the settings option and adjust the offset temperature to line it up with the boiling point of water.
Try holding down one button at a time until the unit starts flashing.
I fixed a CDL auto draw for a friend of mine this summer and unit says CDL on the front of course. Then when you open it up and take the cover off I was able to get manufacturer and model number. Got the full manual online and fixed it in setting menu.
Probes can be tested with a multi meter also. I check his and it was fine.