Where is electrode in water heater 2008 holiday rambler

If it's gas, turn off the propane.

igniter coil could be bad.it creates a high voltage spark across the electrode. be sure electrode is set to specs.

Any RV dealer should have them in stock.

Your thermo coupler may be going out. If the thermo couple does not sense heat it will shut the gas off. This is a safety feature. Once you replace that you should be ok.

Your electrode acts as flame sense as well. Remove electrode and clean it thoroughly/carefully especially at end where flame would be sensed and retry. Be sure connections on high tension wire is good and clean as well as connector and contacts on circuit board as well. If still same result, replace electrode.

If you pull pressure relief valve open slightly (carefully ) and water shoots out, your good. The red light inside is not overtemp, it is to alert you to the fact that the heater did not ignite. If your sure you have by-pass in proper position on back of tank, try removing the cut-off that is inline by pressure relief valve. It is enclosed in that small clear plastic jacket and wire runs to thermostat. Pull at each end and remove it from the circuit, then put the male spade from wire directly on thermostat connector where the cut -out was attached, then try water heater. If it works, replace that cut out. Don't leave it off, it's a safety device that shuts off gas to water heater in case of flame up.

If it is like a standard water heater, it will be mounted right in the flame of the pilot. There may be a bracket holding it or a clamp with a screw. If you can get it out, the other end is held in by a brass screw into the gas valve.
Once you get it out, an RV outlet or plumbing supply house should have one.

Try removing the thermocouple where it attaches to gas control, and spray a little WD-40 in the hole, then spin a rolled up small piece of steel wool in the hole as well, then blow it out with compressed air if you can. Then reconnect thermocouple. Make sure thermocouple tip is getting good flame under it, and if that doesn't cure it, then it's time to replace gas control.

Hi, W/D here.
You'll need an electrical test meter to find what ails ya. The reset button was a good idea, and it may help. If not:
1. Disconnect the power to the water heater (Trip the breaker to "Off").
2. Check the electrodes where they screw into the tank. There are two terminals. Test for continuity. If either electrode tests open, replace it.
3. With power on the heater, test for power through each thermostat to the electrode and back. Replace any defective thermostats.
Hope that this helps you, --W/D--

this is not a typical unit, you might want to consider calling the company for directions, go to there web site if they have one and look for elements and where they are located