Thermostats In Aquarium Heaters
The thermostat measures the temperature of the water and switches the heater on and off accordingly. By doing so a specific temperature can be maintained.
You can often hear a small click as the thermostat switches the heat on and off. Many aquarium heaters will also have a small light which indicates weather the thermostat has selected the on or off mode at that given moment.
Most thermostats for heaters use a bi-metal strip. The strip uses two types of metals that expand and contract at different rates. Though fairly simple in principle a fairly accurate device can be manufactured.
Some thermostats are also manufactured as separate units to the rest of the heater. In this case the heater plugs into the thermostat which has a probe that sits in the aquarium water. Often these will utlize a computer chip rather than the bi-metal strip method.
If a heater element does not turn off and the water is hotter than the set temperature this can be a sign of heater thermostat malfunction.
The aquarium heaters for sale below are listed on eBay.
