It is possible. With a battery power source and some kind of heating element that creates electrical resistance in order to transfer that energy into heat; it could be done. I would not recommend that you try.
Water heater fan? I have never seen a "water heater" with a fan. Possible a boiler, hot water heating system. Assuming you are talking about a "water heater" in a house. Please give a little more information on where it is and what it is intended to do.
It is possible a little low on coolant and has an air bubble in the heater core.
It is a water heater, not a hot water heater. There would be little point in using a hot water heater. I assume that is your point.
It's possible hard water deposits have built up inside. To prevent this and the early demise of your water heater, drain and flush the heater at least once a year.
No, there'no other way. If your car has no aircon the job is does not take to long and isn't too difficult - wth aircon that's another story... Alternatively you can bypass the heater element in the engine room, tricky because theres little space but possible
Cichlids do generally require heaters. As a general rule of thumb, 76-80 degrees F is about where the water should be kept with as little fluctuation as possible.
Called a Heater Core in North America. This is a little radiator to make the air in the car warm
The price of a baseboard heater is going to depend on the brand and length of the heater you are going to buy. You can get one for as little as $27 for a 30 4ft. baseboard.
There is a little orifice in the heater with a different size gas supply hole to be changed.
Thermostat stuck open, heater core clogged, or the heater temperture control vlalve is defective.
It will take a little longer for the cooling system thermostat to open up if the heater fan is on. The heater fan and heater core act like a small radiator and disperses heat energy when in operation.
The heater door control on a Blazer can be replaced by purchasing a new one. The heater vent will pop out with a little nudge from a flat tipped screw driver. Then insert the new heater vent door control.