Other causes can include faulty sensor, clogged in-line filter, clogged water softener, sediment in pipe, sediment at elbow, bad check valve, water leak, etc.
Take a moment and rate answer: And take advantage of fixya expert assistance live. For a price, expert works with you while you work on water heater or any do-it-yourself project. Fixya is always less expensive than a service call.
Error codes are considered start-point for troubleshooting. Error code 11 is No Ignition or inadequate gas, and can be air in gas line, bad gas solenoid, un-grounded appliance, bad igniter, damaged wiring harness. http://waterheatertimer.org/pdf/ErrorcodeTroubleshooting.pdf
Tankless require yearly maintenance to combustion chamber and burner parts. Prescribed maintenance should correct problems listed in error code 11.
Why is it always Rheem problems?Every water heater problem at fixya is Rheem.And Rheem doesn't post any service manuals, like the other two big manufacturers, AO Smith-American, and Bradford White.Rheem 2012 manual says if error 13 still displays, then contact installer or service technician. Mo Money buddy.This is about oxygen sensor, poor combustion, bad venting, inadequate air supply, failed sensors, etc.Get more fresh air to unit and see if that solves problem. The call service technician, and get out wallet.Copy following link for Rheem-richmond tankless troubleshoot.http://waterheatertimer.org/Troubleshoot-Rheem-Tankless-water-heater.htmlMaintain water heater according to instructions in manual to avoid common error codes. Of course this means you have to service the unit each month, and each year, without guarantee the thing will work correctly. If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7
You might have crossover problem caused by bad faucet cartridge.http://waterheatertimer.org/Crossover.htmlThe green standby light should come on when 240Volt power is applied. Page 6 manual. Both red lights should come on when tankless is activated. Page 6 manualRTE 13 requires 60 amp breaker and 6 gauge wirehttp://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.htmlhttp://waterheatertimer.org/pdf/Rheem-TanklessElectricUC_AP15447.pdfFactory temperature setting is usually default 120 degrees.Adjust temps page 11 manualThermostat calibration is always approximate.120 degrees is not hot enough to burn the skin.Exceptionally cold incoming water temperature can cause tankless not to heat enough hot water: install tempering tank to preheat water to room temperature.Tankless cannot be exposed to more than 11 grains hardness in water. Delime tankless yearly, clean water filter monthly, do not install low-flow restrictions or conserve water since the flow rate must remain high for tankless to activate.Rheem does not post service manuals for their tankless water heaters.Call Rheem 800 432-8373 If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7
Rheem, Richmond, Ruud, and Paloma are all the same manufacturer. After about 9 months, my tankless RTG-74PVN started giving me error code 11 and cold water!. I fixed it by cleaning the burner, as shown in this video:www.howtolou.com/clean-a-burner -Lou