Step-by-step: Recalibrating Won Bros Digital Heaters

tgunn

New member
The old adage goes, "You get what you pay for."
Products such as the Won Bros II digital titanium heaters are proof this is not always the case. :)

I have three Won Bros II digital titanium heaters. I thought, "great, digital, these will be the best for my reef". Well, out of the box, all three read DIFFERENT temperatures. In fact, the temperatures they display were all off from my actual tank temperature.

Luckily, it's actually possible to recalibrate the temperature on these heaters. In fact, it seems just taking one of mine apart and fiddling with the calibration dial seemed to fix the problem I had where the the heater was GROSSLY miscalibrated (ie it read 94F). I suspect salt works its way into the heater control and interfers with the sensitive potentiometer responsible for calibation.

If you've got 'em apart use some electronics cleaner or compressed air to give it a good clean out while you're at it.

Okay, so first step is to remove the 4 small phillips screws on the back on the heater.

WARNING: DO NOT PLUG IN THE HEATERS WITH THE COVER REMOVED. I did this for simplicity. If you are not careful you could zap yourself good! For safety's sake you should adjust the calibration, reassemble, plug in and test, and repeat if required.

So here's my three heaters, one with the cover removed:
IMG_1584.JPG


As you can see they're ALL way off the actual tank temperature which I measure with a 1-wire digital thermometer linked to my PC.

Using a small phillips screwdriver, adjust the tiny potentionmeter in the heater. Make SMALL adjustments until the temperature shown matches what your reference thermometer says.
IMG_1585.JPG

Left lowers the temperature, right raises it.

And here's the end result:
IMG_1586.JPG

For the FIRST time ever the are all reading the same temperature. Wow. I still don't trust them and I plan to eventually get a 2-stage Ranco to control them. But at least now the "eye candy" aspect works.

Tyler
 

RandyStacyE

New member
Awsome! If I opened one of those I wouldn't know what the heck I was looking at.

I've always had the Won submersable heaters and had no problems with them. The only time I've had a problem it was due to my error like allowing the probe to come out of the water. There's always a first time for everything though.
 

tgunn

New member
<a href=showthread.php?s=&postid=9884311#post9884311 target=_blank>Originally posted</a> by RandyStacyE
Awsome! If I opened one of those I wouldn't know what the heck I was looking at.

I've always had the Won submersable heaters and had no problems with them. The only time I've had a problem it was due to my error like allowing the probe to come out of the water. There's always a first time for everything though.

The calibration potentiometer has a little star head on it for making the adjustments. There should only be one.
Something like this (not from Won Bros heater, but to give an idea):
5.jpg


Yeah, I must've got a couple duds in my batch. One was already replaced, and I was about to toss the other because I couldn't set it high enough to get the heater to turn on any more.

Luckily the fix was pretty easy.

Tyler
 

tgunn

New member
<a href=showthread.php?s=&postid=9885167#post9885167 target=_blank>Originally posted</a> by BeanAnimal
I still wouldnt run one of them without a RANCO or other "real" temperature controller :)

I agree.. I'm planning on a 2 Stage Ranco so my heaters aren't fighting against the fans. :)

Tyler
 

tgunn

New member
:lol:
Well, so much for that. One of the heaters is already drifting to read 84F... Yet another is off by a degree.

Oh well. :)

Tyler
 

RandyStacyE

New member
Bummer.

I don't know much about the RANCOs or the other controllers, I never owned one. Are they intended to controll the temp while the heaters just ... heat?
 

JagerEinheit

New member
Randy the rancos actually read the temp, then the dual stagers either cut on your cooling apperatus on at one preset or your heater on at another. so if you have heat at 78 and cool at 80 it will balance the two items so they are not working against each other. end result you can use less electricity, and have better peace of mind if you are not using a full controller setup that can do that for you.

rancos are like 125 ish i think for the dual controller the single is not worth its cost for aquarium use versus the double except in certain situations of light control maybe, but the dual stage is what everyone is after.

highly accuurate when used correctly and well worth their cost.
 

RandyStacyE

New member
I will end up using one of those controllers when I consolidate my tanks.

I'm not completely turned off by the Won heaters ... yet. They've always served me well and they have proved to be better than those non-submersible glass heaters.
 
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