Look into reptile thermostatskingpoiuy said:Cool, thanks dutch dude, I was kinda wondering what the deal was. I wish they made a device that would turn off a plug when it got to a certain temp. Basically a thermometer with a switch. Would be nice.
I wrote an article for the GPAS newsletter describing this and how to clean the contacts of a heater to prevent failure. The article hasn't been printed yet but as soon as it is I'm going to try and get it out to different fish clubs for reprint in their publications. I only go through the overhaul of a Marineland Visitherm as that was the only heater I had in need of repair at the moment but it appears that the dissasembly and repair of most heaters is very similar and can be done with few or no tools. The downside as with any attempted repair of a sealed device is that there is a risk you'll destroy the seal, I recommend only attempting to clean the contacts of a heater that has already shown condensation inside the heater as the seal is already compromised and won't be made worse by dissasembling the heater.Dutch Dude said:To everyone who reeds this post I want to add something abouth heaters. The problem with the heaters is that after a certain number of switching the contacts get burned, causing high temperatures and eventually the contact get welled becouse of this and thats the reason why it doesn't turn off any more. The number of switching and the qualety of the contacts along with the power of the heater determines lifespan of the heater. If the heater is oversizes it switches on and off for short periods. If its malfunction and doesn't turn off, the heater will raise the temp to a high temp. If the heater is on the edge of keeping the tank at stable temperature it will turn on and off for longer periods so a reduction in turning on and off (=longer lifespan). If the heater malfunction and doesn't turn off the temp raise but not as high as an oversizes heater. Something to consider when you buy a new heater. Unfortunately some species need a stable temperature and for that need a bit oversizes heater. Just an example. Keep in mind that a 300 Watt heater on a 55 gallon is to much and a 200 Watt will be more than sufficient even for temps up to 82 F and a 150 Watt will be fine in most situations. Selecting a good qualety heater is important! Don't save 10 bucks on a cheaper les reliable heater. Jaeger turns out to be reliable along with a stable temperature. On the package you can check minimum and maximum tanksize for the several types along with the power consumption.
Unfortunately we never know when the heater breaks down. Some spirals break down so it won't heat any more and some doesn't turn off any more. Unfortunately both situations can couse death of your fish. Perfect would be to observe your fish at least every day and check the temp and check if the filter is still running.