Rheem tankless gas water heater error codes

Rheem tankless gas water heater code 03

Communication failure between water heaters, the remote control and/or the manifold controller.

Check that the remote control cable and connections look intact.

Rheem's pocket manual lists this as a communication failure and gives diagnostic checks for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 11

Error: the flame rod does not detect flame, commonly a gas supply and/or venting problem. Rheem's use and care chart gives the possible cause as the gas shut-off valve not being fully opened.

Check that the gas shut-off valve is fully open.

Rheem's use and care chart says to check the shut-off valve and open it completely. The pocket manual adds that the unit's diagnostics are the gas supply and venting, the igniter rod, the flame rod and the gas control valve, and that DIP switch 2, the altitude setting, must be set properly. It says that if all components test OK, you must thoroughly inspect the gas supply and venting. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck.

If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 12

Error: the unit detected the presence of flame and then lost it. Rheem's use and care chart gives the causes as gas service being interrupted, or LP gas running low on LP models.

Check whether gas is on to other appliances, and the LP tank level on an LP model.

Rheem's use and care chart says to contact your gas utility company if service was interrupted, and to refill or replace the LP gas container if it is running low. The pocket manual says this is commonly a gas supply and/or venting problem and to check DIP switch 2 and the flame rod. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck.

If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 14

Error: the over heat limiter or over temperature limit switch activated. Rheem's use and care chart words it as the water heater overheating.

Turn the water heater off and let it cool.

Rheem's use and care chart says to contact a dealer or qualified service technician. The pocket manual says an activated limit is normally caused by inadequate or wrong gas supply and/or venting, and on a high-efficiency unit the over temperature limit switch monitors the vent temperature. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck.

If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 15

Error: the hot water temperature and/or heat exchanger temperature reached 207 degrees F for more than 15 seconds.

Turn the water heater off and let it cool.

Rheem's pocket manual gives this explanation and a diagnostic sequence for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 16

Error: the outlet water temperature is above the set point on the remote control. Rheem's pocket manual says to check the outlet thermistor first.

Note the set point on the remote control and the water temperature at the fixture.

Rheem's pocket manual says to check the outlet thermistor first. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 31

Error: an inlet thermistor malfunction. Rheem's use and care chart words it as a faulty inlet thermistor.

Rheem's use and care chart says to contact a dealer or qualified service technician. The pocket manual lists diagnostic checks on the thermistor. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 32

Error: a heat exchanger thermistor malfunction.

Rheem's pocket manual lists diagnostic checks on the heat exchanger thermistor. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 33

Error: an outlet thermistor malfunction. Rheem's use and care chart words it as a faulty outlet thermistor.

Rheem's use and care chart says to contact a dealer or qualified service technician. The pocket manual lists diagnostic checks on the thermistor, and code 16 says to check the outlet thermistor first. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 34

Error: an ambient thermistor malfunction.

Rheem's pocket manual lists diagnostic checks on the ambient thermistor. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 35

Error: an improper thermistor connection. Rheem's pocket manual says the unit has four thermistors and one or more may have a poor connection or be connected in the wrong location.

Rheem's pocket manual gives this explanation and a diagnostic sequence for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 52

Error: a PGFR malfunction. Rheem's pocket manual says the PGFR, the proportional gas flow regulator, is the only modulating valve in the gas control valve.

Turn off the gas at the shut-off valve.

Rheem's pocket manual lists PGFR diagnostics for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 61

Error: the blower motor speed was not appropriate for proper combustion. Rheem's use and care chart words it as a faulty blower motor.

Rheem's use and care chart says to contact a dealer or qualified service technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 66

Error: a water bypass valve malfunction. Rheem's use and care chart words it as a faulty bypass motor.

Rheem's use and care chart says to contact a dealer or qualified service technician. The pocket manual says to turn the remote control temperature down to 102 degrees before measuring voltage, because the bypass valve activates at that temperature. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck.

If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 71

Error: a gas control valve malfunction in the inlet solenoid.

Turn off the gas at the shut-off valve.

Rheem's pocket manual lists diagnostic checks for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 76

Error: a communication fault with the remote control. Rheem's pocket manual says the remote control is not communicating with the control board.

Check that the remote control cable is connected.

Rheem's pocket manual lists remote control diagnostics for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 79

Error: a blower motor current fault.

Rheem's pocket manual lists diagnostics for a technician. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 88

A reminder to flush the heat exchanger and/or replace the water treatment filter. Rheem's use and care manual says the optional maintenance notice shows code 88 after a set number of hours of combustion.

Note whether the notice is expected: it is an optional control that is inactive by default.

Rheem's use and care manual says it is highly recommended to flush the heat exchanger and/or replace the water treatment filter (if applicable) before clearing the code, and then gives steps to clear it: turn on the remote control, press and hold the DOWN and UP buttons for 5 to 10 seconds, with the gas and water shut off as the manual's steps describe. The maintenance notice hours can be set to 500, 750 or 1,000 hours, or off.

Rheem tankless gas water heater code 90, 99

Error: the unit was operated before the vent was installed, or it detected blockage in the venting during the pre-purge or post-purge cycle. Rheem's use and care chart gives the causes as the air intake or vent exhaust opening being blocked, or the vent pipes on the vent termination not being connected properly.

Check that the air intake and vent exhaust openings are clear.

Rheem's use and care chart says to remove any blockage (the air intake requires 12 inches, 30 cm, of clearance) and to contact a dealer or qualified service technician if the vent pipes on the vent termination may not be connected properly. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck.

If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code 92, 93

High-efficiency (condensing) units only. Rheem's pocket manual says code 92 is a warning code and the unit continues to operate but will eventually shut down.

Note whether the unit is still delivering hot water.

Rheem's pocket manual gives separate diagnostics for 92 and 93 on high-efficiency units. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display. If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.

Rheem tankless gas water heater code P1

Warning: not enough water flow to operate the unit. Rheem's pocket manual says no hot water is delivered when water is flowing and the remote control shows P1.

Turn on more hot water at the fixtures.

Rheem's use and care chart solution is to increase the water flow from the fixtures. The pocket manual's checks: turn the water supply off, turn the remote control off for 10 seconds and back on, then turn the water back on and test the nearest hot fixture; make sure the hot and cold lines are connected to the right connections on the unit; check whether a dirty in-line water filter is restricting the flow; and check for a plumbing cross-over in the home. Rheem's steps when a code shows: turn on a hot water faucet and recheck the remote control display.

If the code stays, turn off the faucet and the water heater, unplug the water heater for about 30 seconds and plug it back in, follow the chart for your code, restart the water heater and recheck. If the code is still shown, turn off the faucet and the water heater, note the code and call for service. If a code is not in the chart, turn the water heater off immediately and call for service.