Calibrating a Marineland Precision Heater

[apastuszak]

I was an idiot and burned out the heater in my basement aquarium. I had a 300W heater in there, because the basement can get as cold as 66°F. Well, I ran out to Petco and bought a 200W Aqueon heater, because that was the most powerful heater they had. I went home and ordered an Marineland Precision 300W heater, mostly because it has a lifetime warranty.

In my setup, I have a Home Automation tool called Home Assistant setup, and I have my heaters connected to a Sonoff TH16 temperature controller.

The way things are setup:

1. Home Assistant turn on the heater when temperature goes below 77.0°F and turns off when the temperature is above 77.9°F
2. The TH16 itself has rules on it that turns on the heater if the temperature drops below 76°F and turns the heater off if the temperature goes above 78.9°F.
3. The thermostat on the heater is set to 80°F

So, if Home Assistant crashes and can't shut the heater off, then the TH16 itself will shut the heater off a degree hotter, and if the switch glitches out, then the heater's thermostat itself will turn off the heater off at 80°F.

In order to make this whole thing work, I needed to calibrate my heater so I know what the actual temperature is when the setting is 80°F.

I took a glass, filled it with ice and then added water. Waited 3 minutes and stuck my thermometer in the water. The temperature should read 32°F. My thermometer was at 32.5°F. I then boiled some water, which should be 212°F (at my elevation and barometric pressure, it's actually 211.4°F). I check the thermometer and it shows 211.9°F. So I know my thermometer is only off my 0.5°F.

I then get a Home Depot bucket, throw the heater in, fill it with water, toss in a power head and the thermometer. I turn the pump on and wait 15 minutes. Then I plug in the heater and walk away for an hour.

An hour later I come back, and check the temperature. The heater is set to 80°F and the actual water temperature is 88.7°F. Corrected for the thermometer shift, the temperature is actually 88.2°F! That means my thermostat is off my 8.2°F!

And that seems to be pretty consistent. If I dump the water out and replace with cold water and then set the thermostat on the heater to 78°F, after an hour, the bucket is 86.7°F.

i think that having a thermostat discrepancy of 8.2°F is just WAY TOO MUCH of a discrepancy. The discrepancy is consistent, but it's still huge. I hate to think that I would set this to 80°F and drop it in a tank and end up with a tank that is 88.2°F instead.

Am I crazy in thinking I should return this thing immediately? Anyone else seen these kind of wild calibration inconsistencies in Marineland heaters?

 

[GraphicGr8s]

Who cares what the dial reads? I sure don't on my heaters. I started with the old Supreme heaters that had no temp markings and that meant we had to keep an eye on temps when setting.
I put a thermometer in and adjust to the temp I need and get on with life.

I've checked a bunch of different digital thermometers for accuracy. I've checked a bunch of the same make and model. None of them read the same. But then again in fishkeeping if it is within a degree or 2 it really doesn't matter.

Personally if a tank needs a 300 watt heater I put in a 150 and a 200. If either fails the other can keep the tank at a temp that won't kill the fish. If one sticks on it can't overheat the tank. If one fails off the other will keep the tank close to temp. At least close enough the fish won't die. And it gives me time to get new one.

 

[apastuszak]

I have a temperature controller in place to kill it, so it should not stick on and cook my fish. If it doesn't turn on, I will get an alert on my phone and an email.

 

[FreshyFresh]

Did I miss how you burned out that 300w?

Save your boxes and receipts for those suckers. Most Aqueons and Marinelands have lifetime warranties. One call or email is typically all it takes to get a new one shipped to your door. Then again, you did the right thing if you broke it. LOL.

I get what you're saying though. If you need to run a higher wattage heater than you normally would for a particular setup, it is wise to use a separate temperature controller.

I tend to run wattages that are just enough. I haven't had one overheat a tank too badly yet.

 

[apastuszak]

Did I miss how you burned out that 300w?

Save your boxes and receipts for those suckers. Most Aqueons and Marinelands have lifetime warranties. One call or email is typically all it takes to get a new one shipped to your door. Then again, you did the right thing if you broke it. LOL.

The original 300W was a Via Aqua. It was left on during a water change. It wasn't pretty.

 

[FreshyFresh]

The original 300W was a Via Aqua. It was left on during a water change. It wasn't pretty.

It is amazing how quickly they go Chernobyl.

I've got myself into the routine that all my tanks have their own power strip for their lights, heater and filters. My water changes go below my filters, so the whole strip gets powered down.

 

[apastuszak]

I called Marineland tech support and they told me to return the heater to Amazon. I bought an Eheim Jäger to replace it. I like the fact that you can calibrate these heaters.

 

[GraphicGr8s]

I have a temperature controller in place to kill it, so it should not stick on and cook my fish. If it doesn't turn on, I will get an alert on my phone and an email.

All well and good. If you're not in a cold climate. Alerts are great if you are close enough to do something about it. I always seem to have trouble with things when I am 1200 mile away. At least with 2 heaters I am covered.

 

[apastuszak]

My only concern with running 2 heaters is that one will fail and the other backs it up and I never know the first one failed because the first one keeps the tank up to temperature.

 

[dougall]

You don't have 2 heaters that will completely heat the aquarium to where you want it, you have them so that it will heat part way.

So you should notice that the temperature is a bit low which would give you cause to check. to check them you can make sure that they are 'on' and producing heat.