FinnexHC-820M Digital Controller, 3-Digit Display and Control, Calibration Capable, Audio Alert, Precision Accuracy, Black

This might be the best heater out there. No cheap knock-off here! Very accurate....small deadband. This will keep you water temp right where you want it, and the high capacity will get you there quickly on initial setup.

I'm giving this zero stars! Bought this to replace my old finnex controller I use with a 800w finnex titanium heater for when I mix water. This controller almost caught fire after its 3rd use. I'm past the return date due to I only use it for when I mix new water. If I wasn't in the room when this controller malfunctioned my house might of burned down!!!!! I heard something clicking then realized I smelled a electric burning smell looked over and the controller was going crazy unplugged the unit and took it of its mount and it was so hot I couldn't hold it.

Out of water sensor kept beeping when in the water. Reset it time after time, and finally returned it.

Been using this for a while now it replaced my older model finnex controller. Looks great super easy to use works as i would expect!

Owned three pro Finnex controllers and titanium heaters and each died within a few years of one another. Warranty is only 6 months. Contacted company about it and they never got back to me. You'd think they would be curious as to why their products fail and want the defective products back for quality control ? No. Instead I was rudely dismissed and told my warranty was over.

I was anxious when this model came out from Finnex because I really like the brand. I even bought one of the first two that were available for my two new tanks (55 & 120g planted freshwater) with their titanium heaters. Everything was great for a several months, then the low water sensor on the 120 started alerting for no reason. Fortunately it was within (or close to) the warranty period. I contacted Finnex and corresponded with Howard. (He was nice enough.). I had to supply a bunch of specifics about my tank setup and water quality. Fortunately I had purchased additionally the other one for my 55 at the same time, and I told him it was working (at that time) just fine. I had to send the unit back to them with my shipping. It took several weeks for them to replace the unit. There was no comment from them about my unit; I just received a new one which I replaced on my 120. Fast forward about 1.5-2 yrs. The 55 unit started to have the same problem — the low water alarm sounding consistently without reason — and once it starts it is permanent. I just unplugged it. Fortunately with my tanks in my heated home with the community fish I have I can get by with it. I contacted Finnex again even with the same email thread that I had used prior and told them that I really liked their products up to now, but I think that they might have a problem with that model considering my situation. They wanted me to go through the whole situation of describing and sending the unit back for several weeks. I decided to try something else. I contacted several online aquarium stores that carry Finnex controllers. One person who seemed to be very knowledgeable and helpful, said that the model that I have works fine on saltwater tanks, but has problems on freshwater tanks especially with very good water (which I have excellent well water). He suggested that I get the HC-0810M which doesn’t have that problem. So, I bought one of those. Unfortunately I have not hooked it up yet since my aquarium cabinet is difficult to install it. Fast forward another approximately 1.5 years. My 120g that I replaced under warranty has just gone out with the same problem! Fortunately I don’t have the discus that I originally had planned on in the tank which need high temperatures. I now see that Finnex has a disclaimer on their website for this model about the sensor and the types of water. For me, I am not sure what to do. Fortunately for me again, at the present, I can get by with no heaters on my setup. I guess that I wish Finnex had been more responsive to a once-devoted customer. Three units in about three to five years is not acceptable for a high end product. Maybe they should compensate for another of their products that does work.

Worked fine for the first eight months. Temperature probe still works but not out putting 120v for heater.