Precision Submersible Heaters

Precision Submersible Heaters
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Product No. ML90648-00
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  • Adjustable temperature dial clicks through each degree for accuracy
  • Thermal switch automatically turns off past max preset and resets once the temperature lowers
  • Advanced mica core heating element for efficient heat transfer and enhanced durability
  • Three window positions to view the temperature display

I would like to make a return on a heater i bought two years ago. How might I do so?

Asked by: Marty99
You would need to email or call us directly, 1-800-322-1266, cut the cord of the heater, provide us with a picture of the heater with cord cut, and the lot code off of the heater, along with your information. Once the heater is replaced, your warranty is fulfilled. BREX
Answered by: BREX
Date published: 2016-07-26

How do you reset the heater?

Asked by: jeffmr
Unplug it, and let it sit, in the tank, for at least 15 minutes. Set the temperature where you want it to be, and plug it back in. BREX
Answered by: BREX
Date published: 2017-01-08

What happens if you don't let the heater sit for 15 minutes before plugging it in?

Asked by: jeffmr
It will not acclimate to the tank water temperature properly, and either crack, explode, or just not read correctly, causing it to not heat properly, and needing to be re-set. BREX
Answered by: BREX
Date published: 2017-01-08

I have a biocube 14 with the heater in the back middle chamber and a nanobox tide mini led light. The temperature in the tank reads 76 when the heater is set to 69. Why is this?

Asked by: jeffmr
At this time of year, it is easy to a tank temperature to be high. I assume you cannot see if the heater is turning on or off since it is in a back chamber, so you can try unplugging it for a day and seeing if the temperature drops. If it doesn't, then I would say that your room temperature is the issue. I don't use heaters in my tanks at this time of year, for this reason. It generally isn't necessary, unless you are really cranking the AC. If the temperature does drop, then the heater may not be working correctly or being in the back chamber does not allow for enough circulation, creating an issue with properly heating the tank. BREX
Answered by: BREX
Date published: 2016-06-28

How do I get one of the clip-ons that hold the suction cup? One of mine broke out of the box.

Asked by: chipmunk
Just call or email us with your information. 1-800-322-1266 or techsupport@marineland.com BREX
Answered by: BREX
Date published: 2016-06-13

Is a VISI THERM Type VTH150 submersible?

Asked by: Anonymous
Yes, it is fully submersible and should be at all times. BREX
Answered by: BREX
Date published: 2016-06-06

Can you use a heater and if so which one is recommended for your cylinder tank?

Asked by: Dawnee
If you are referring to the 6 gallon Pillar tank, yes, you can use a heater from 25-50 watts with this tank. BREX
Answered by: BREX
Date published: 2016-05-23

I am just wondering, but how much does this cost for a 65 gallon fish tank?

Asked by: Robert Guiney
You would need at least 5 watts per gallon of water or at least 325 watts total, so I would recommend either two of the Precision 200 watt heaters or one of the Precision 400 watt heaters. Pricing will depend on where you purchase them but they retail for between $26 and $45. BREX
Answered by: BREX
Date published: 2016-05-02

I am looking for replacement suction cups and maybe even the holders as well for the heaters, where can I get them? Thanks

Asked by: justaname
We do not sell these separately, I will email you for your information. BREX
Answered by: BREX
Date published: 2016-05-02

I have my heater set for 76 degrees. the light on the heater keeps flickering on and off for a few minutes, then it will go off for hours. When I test the temperature of the water, it is around 72 degrees. What is the issue with my heater?

Asked by: carrcs
Good morning, Thank you for your inquiry. Please double check the thermometer to make sure it is working correctly as well. If so, then we would be able to help you in regards to the matter directly at 1-800-526-0650 with our Customer Care Line.
Answered by: MINI
Date published: 2016-03-31

I recently purchased a 10 gallon tank that includes your OEM aquarium heater. I set the thermometer to the line in between the + and -, trying to achieve a 78 degrees. I noticed the other day the light is off, is this normal?

Asked by: paige
Good morning, Thank you for your inquiry. The light will come on and off during the regulation of the 78 degree temperature in your tank. If the light is on, this typically indicates that the tank temperature has fallen below 78 degrees and the heater is heating the tank back up. If the light is off, then the tank should be at a steady 78 degrees. We would recommend that you place a thermometer strip on the tank to make sure that everything is correct in your tank. MINI
Answered by: MINI
Date published: 2016-03-31

What is the actual temperature of the heater? If heating the water to 84 degrees, does the tip heat to 130 degrees, or some other temperature, until turning off?

Asked by: doctor of fun
It is approximately 130 degrees Fahrenheit. BREX
Answered by: BREX
Date published: 2016-03-23

I have water in where it shows the temp? Is that ok?

Asked by: Tkb2564
Some minor condensation, such as droplets is okay. More than that would not be okay. BREX
Answered by: BREX
Date published: 2016-03-22

I bought the 20 gallon tank kit today. How do I turn on the heate . I have it completely submerged. I plugged in and waited 15 minutes. Now what. 

Asked by: TNicole76
You should have a + (plus) sign and a - (minus) sign, along with a triangular mark sort of in the middle between them. The mark represents 78 degrees Fahrenheit. To turn the heater on, place it in the tank for 15 minutes THEN plug it in. Set the dial so that the pointed portion points toward the mark in the middle, then leave it for several hours. Check it periodically, over 24 hours to do any fine tuning adjustments that may be needed. BREX
Answered by: BREX
Date published: 2016-03-22

My Precision worked perfectly the first week, but now I have to adjust it a lot to keep the water around 80 degrees. It has gotten so far out of wack that the reading on the dial is 77, but 2 thermometers read 82. Can it be re-calibrated?

Asked by: Donna74
I must report that my heater is working perfectly again. It was the new LED light overheating the water. Although to my touch, I could barely feel any heat at all from it, I did notice a change when I opened the aquarium cover to allow for more air circulation. Thankfully, I have fish that don't typically jump. But if needed, I now have a little 4" desktop fan to disperse the heat from the lights. Thanks so much.
Answered by: Donna74
Date published: 2016-03-15

What is the gauge on the front for? First day of use gauge read about 78 with temp control set at 78. Second day heater gauge dropped to 65 and has stayed there. A second separate temp gauge is reading 78. There is random condensation on the gauge.

Asked by: SeaSalt
The gauge is actually part of the knob on top of the heater. It simply allows you to see what temperature you have set the heater at, from the front. It cannot move on its own at all, so I'm not sure how you saw it "drop to 65". It only moves when you twist the knob up top. You would need to have a thermometer separate from the heater, on the tank in order to be able to determine what the water temperature is at any given time. BREX
Answered by: BREX
Date published: 2016-03-10

My heater won't let me shut if off and the temperature keeps fluctuating. What is wrong with the heater.  One moment it is too hot & a day or 2 later it is cold. We just got a new thermometer and know that's not the problem. What's wrong with our heater?

Asked by: JP06
Heaters typically do not fluctuate. They will run cold or too warm, but not fluctuate between the two. You may have an environmental issue like sun coming in through window, a drafty area of the house, some other piece of equipment causing the issue such as some filter systems or lights. Use two thermometers, different styles to compare the temperature. BREX
Answered by: BREX
Date published: 2016-03-07

Hope this isn't a stupid question, got a 38gal tank with an OEM heater, do I fully submerge it under water? 

Asked by: FigNewton
Actually, it's a common question for all heaters. And yes, it is fully submersible. You never want more than the top inch or so out of the water. BREX
Answered by: BREX
Date published: 2016-04-14

My 200w heater (ml90443) stop working after about a month. Light stays on,but not heat up. What's the problem?

Asked by: Fish guy
Make sure you are checking a thermometer to determine the temperature of the water. Most people seem to go by the way it "feels". At 78 degrees, it will feel cold to you. If the water temperature is the same as the room temperature, then you are correct, the heater is not working. In this case, call our Consumer Relations Team directly for assistance. 1-800-322-1266. BREX
Answered by: BREX
Date published: 2016-03-04

My Heater is flickering on and off rapidly. Is this normal? 

Asked by: jayh619
The light may flicker, yes. This does not mean the heater is not heating properly. As long as the light goes on/off periodically and the temperature is correct as per whatever thermometer you are using, the heater is functioning correctly. However, if it is having additional issues, I would recommend contacting our Consumer Relations Team at 1-800-322-1266 for further assistance. BREX
Answered by: BREX
Date published: 2016-03-02

what is the temp setting for a beta

Asked by: Terry86
80-84 degrees Fahrenheit. BREX
Answered by: BREX
Date published: 2016-02-29

my tank is only 5 gallons, is that heater ok for a beta

Asked by: Terry86
You would need to purchase the smallest one, which is 50 watts. BREX
Answered by: BREX
Date published: 2016-02-29

What is the temp. Range of your heaters

Asked by: Mike R
65-89 degrees Fahrenheit. BREX
Answered by: BREX
Date published: 2016-02-29

The heater that I got had 2 plastic holders to hold the heater. One of the holders melted and the other broke. Is there anywhere that I can get replacement holders? The heater is about a month old and works great so I don't want to buy another one yet.

Asked by: Morgan1205
Good morning! We would be more than happy to help you and will be emailing you directly for more information. MINI
Answered by: MINI
Date published: 2016-02-23

Small bubbles forming on 200 watt Visi-Therm Submersible Heater

Just started using a new in the box 200 watt Visi-Therm Submersible Heater and it works great in my 55 gallon fresh water aquarium set at 78 degrees! Small bubbles gather all over the heater in random fashion around the unit from the indicator light down to the bottom of the heater. I wipe them off and they come back the next day. I'm using the unit vertically with the enclosed mounting bracket. I am not using a bubblier or any such device and the heater is not coming into contact with anything within the aquarium. After two weeks of wiping bubbles off the unit every day, I gave up and just let the bubbles form as they may. (Item number ML90443-00) (Bar Code number 047431904439). One more: Can I adjust, (slide from top to bottom), the enclosed suction cup bracket anywhere along the unit? Thank you very much!
Asked by: PETM
That is normal, all heaters tend to form little gas bubbles like that. The suction cup bracket should be within the top half of the heater, not the lower portion. BREX
Answered by: BREX
Date published: 2016-02-16

how long is the 50 watt heater?

What is the length of the 50 watt heater?
Asked by: Siamese
Typically the lenght of a 50W heater is going to be approximately 6" long. Thank you, MINI
Answered by: MINI
Date published: 2016-03-20

thermal switch safety feature on the precision submersible heater

I was looking through the Q&A on this product, and was a little confused. One answer stated that if you forget to unplug the heater during a water change and the heater is not fully submersed, it will shut off and once it is submersed again, it will work again. Another answer stated that once it is exposed to air while plugged in, it will not work again. Can you please clarify how the safety-shut off feature works? Under what conditions does it shut off (if it overheats, if it runs dry, if it gets below some minimum water level, or all of the above?) Under what conditions will it function again once this thermal switch has been triggered? Also, how long is the 50 watt heater? I have a 10g marineland aquarium (part of the LED kit), and would prefer to keep the heater vertical. Lastly, while I understand it is fully submersible, does it have to be fully submersed, or is there a minimum water line indicator on this model? Thanks so much!
Asked by: Sadfish
We have two different lines of heaters on the market. One is the Visi Therm and one is the Precision. The Visi Therm is the one that once it shuts off, will not come back on. The Precision has a new shut off that WILL come back on, once the heater has been re-submerged, and had time to cool down, and regulate itself. Both shut off any time the water level drops below the minimum water level line on the heater. The 50 watt heater will fit a 10 gallon tank just fine. It is 7-8 inches long. Even though there is a minimum water line, we highly recommend that any of our heaters be fully submerged at all times. BREX
Answered by: BREX
Date published: 2016-02-04

what is meant by Precision Submersible heater?

i just bought a 200 watt Marineland precision submersible heater for my 50 gallon reef aquarium to replace a 20 watt completely submerged, horizontally mounted heater in the sump. I am unclear about whether completely submersing the heater mounted in the sump is desirable
Asked by: ronntazu
It can definitely be fully submerged, either horizonally or vertically. However, not in a sump, no. We do not recommend placing heaters in sumps for safety reasons. They tend to malfunction in that situation due to the fluctuating water levels. BREX
Answered by: BREX
Date published: 2016-02-03

Thermal fuse on the new Precision heaters.

The manual states that this new heater has a "resettable" thermal fuse to prevent overheating. And that once it is triggered should wait awhile for it to come back in operation. Does that mean this will protect the heater during those times we forget to unplug the heater during water changes? Is the glass resistant to temperature shock?
Asked by: Onjie
Yes, if you forget to unplug the heater and it becomes exposed during a water change, the fuse will shut it off. Once water covers it again, and the heater has had enough time to adjust, it will come back on. The glass is no more resistant to temperature shocks than any other normal glass. BREX
Answered by: BREX
Date published: 2016-01-25

I have bought multiple viso therm heaters along the years and I bought them because of the lifetime warranty but the stores would never take them back

So I don't know how to get them replaced or fixed?
Asked by: Kenshobby
Yes, that heater does indeed have a limited lifetime warranty on it. This means that for the life of that heater, if it fails, you simply send it back to us and we replace it for you. The stores do not honor the warranty, the manufacturer does. Once the heater has been replaced, your warranty is fulfilled and completed. Please call or email us directly for the address to ship the heaters to for your replacements. 1-800-322-1266 BREX
Answered by: BREX
Date published: 2016-01-20
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