A thermocouple is a safety device that when heated by the pilot light produces a small electoral current that holds the gas valve (to the pilot) open. Should for any reason the pilot light go out, gust of wind, service interruption , water splash....whatever. The thermocouple will cool off, stop producing current and the gas valve will close. For example, your water heater is in your basement. A strong wind blows down the stairs and blows out the pilot. Or a few inch's of water flood you basement over topping the pilot. With nothing to stop the flow of gas to the pilot light pan, gas would continue to flow unburned in to the room. Then any ignition source could cause a catastrophic explosion.
To change the thermocouple on a Reliant 606 water heater, you will first need to turn off the gas supply and water heater. Remove the access panel, locate the thermocouple, unscrew it from the control valve, and disconnect it from the pilot assembly. Install the new thermocouple by reversing these steps, making sure it is properly positioned and secured.
Oh honey, bless your heart for asking. An electric heater and a thermocouple are like two peas in a pod... if that pod was a dysfunctional family. They both generate heat, but one does it by converting electrical energy while the other does it by measuring temperature differences. So, in short, they're not really opposites, just different ways to warm things up.
There are many pictures of this on Google.
Right below the thermocouple if applicable
$6 to $10 depending on where you are and where you get it from.
THERMOCOUPLE or defective gas valve
Usually less than 1 hour work, ( but nobody will bill one hour) Part costs less than $10 and any competent handyman can do it.
The only power used by a gas water heater is the small current generated by the thermocouple that keeps the gas valve open. It comes on mechanically when the water temperature drops. You don't need house current.
Sounds like you need a thermocouple.
Spillage excessive condensate bad thermocouple draft
It is one or the other. The thermocouple on a gas heater generates a very small current that keeps the gas valve open. A few micro volts. The thermocouple is the small tube that sits in the flame of the pilot light.
It is most likely the thermocouple that is bad. That is what keeps the pilot light on. The thermocouple is the small tube that sits in the flame of the pilot and runs to the control valve.