Rheem water heater 4 blinks: high water temperature limit tripped

Short answer On Rheem, Ruud and Richmond status light models, four red blinks every three seconds mean the high water temperature limit tripped (High Temperature Shutdown). Rheem's only step is to contact a qualified service technician. Power vent and powered damper LEDs word four flashes differently. See what to check

Status light, gas valve LED or display

4 blinks

“High Temperature Shutdown”

Technician

Printed on 15 model series · 8 documents

Rheem Professional Classic Series Ultra Low NOx Skinny Models, Ruud Professional Achiever Series Ultra Low NOx Skinny Models, Rheem PERFORMANCE Ultra Low NOx High BTU Models with Installed Side Water Connections, Rheem Professional Classic Series Ultra Low NOx High BTU Models with Installed Side Water Connections, Ruud Professional Achiever Series Ultra Low NOx High BTU with Side Connections Models, Rheem Performance Ultra Low NOx Skinny, Rheem Performance Series: Ultra Low NOx, Rheem Professional Classic Series: Heavy Duty Ultra Low NOx, Rheem Professional Classic Plus Series: Heavy Duty Ultra Low NOx, Ruud Professional Achiever Series: Heavy Duty Ultra Low NOx, Richmond Essential Series: Atmospheric, Rheem Performance Plus Series: Atmospheric, Rheem Performance Plus Series: Ultra Low NOx, Rheem Performance Series: High Demand Ultra Low NOx Atmospheric, Rheem Performance Series: Atmospheric · AP23698 p. 24; AP22858 p. 23; AP23699 p. 24; AP19928 Rev 02 p. 24; AP16801-2 (08/14) p. 24; AP17110-1 (01/15) p. 24; AP20849 Rev 02 p. 24; AP23060 Rev 01 p. 24

Legend on the gas control label, as reproduced in the manual; printed in red, except in AP17110-1 (01/15), which prints no colors.

The lamp blinks 4 times, then pauses. It shows the count only, not the color; the timing on your board may differ.

DangerGas and carbon monoxide

If you smell gas

Do not try to light any appliance.
Do not touch any electrical switch; do not use any phone in your building.
Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
If you cannot reach your gas supplier, call the fire department.
Do not return to your home until authorized by the gas supplier or fire department.

From "What to do if you smell gas" in Use & Care Manual, With Installation Instructions for the Installer, Water Heaters, Residential Gas - FVIR Certified, p. 1.

Carbon monoxide

“To avoid the risk of fire, explosion, or asphyxiation from carbon monoxide, never operate this water heater unless it is properly vented and has an adequate air supply for proper operation.”

Use & Care Manual, With Installation Instructions for the Installer, Water Heaters, Residential Gas - FVIR Certified, p. 3.

What it means

Four red blinks every three seconds is the label’s “High Temperature Shutdown”. The table under it says “High water temperature limit tripped”, and its remedy is “Contact a qualified service technician. See “IF YOU NEED SERVICE” on page 28” (AP23060 Rev 01, p. 24).

The status light manuals do not say where this limit is or how it resets. The same manual describes two shut-off devices in the combination gas control: one shuts off the gas to the burner if the pilot flame goes out, and a “single use gas shut off device” shuts it off “if the water heater exceeds normal operating temperatures” (AP23060 Rev 01, p. 19). The table does not say whether four blinks is that single use device. If it is, Rheem’s chart says the gas control “should be replaced by a qualified service technician” (AP23060 Rev 01, p. 22).

Check these first

The table’s only step is to contact a qualified service technician (AP23060 Rev 01, p. 24). What the same manual says around it:

If you smell gas, stop and follow the steps at the top of this page.
The manual’s warning for overheating: “Should overheating occur or the gas supply fail to shut off, turn off the manual gas control valve to the appliance.” (AP23060 Rev 01, p. 19).
Have the model and serial number from the rating plate ready. Call your installer, plumbing contractor or service agency first; the manual lists Rheem’s Manufacturer’s National Service Department at 1-866-279-4566 as the next step (AP23060 Rev 01, p. 28).

When to call a licensed technician

For the code itself, in every status light manual (AP23060 Rev 01, p. 24; AP22858, p. 23).
To find and fix the cause. A defective gas control is replaced by a qualified service technician (AP23060 Rev 01, p. 23), and the troubleshooting CAUTION refers repairs of the gas control and other safety devices to qualified service personnel (AP23060 Rev 01, p. 22).
Work on the temperature limits, which the LED tables call TCO and ECO, is for a licensed technician.

Notes for different models

Four means different things on Rheem’s indicators:

Indicator and manuals	What four means	Table’s fix
Status light: AP23060 Rev 01, AP16801-2 (08/14), AP17110-1 (01/15), AP23698, AP23699, AP20849 Rev 02, AP19928 Rev 02, p. 24; AP22858, p. 23	“High water temperature limit tripped”	Contact a qualified service technician
Power vent gas valve LED: AP22511 Rev 02, AP23058 Rev 01, AP23057 Rev 01, p. 37	“TCO activated.” (LCD code 31)	Make sure the tank is full of water; reset the TCO and check that the gas control cycles properly
Powered damper gas valve LED: AP15756 (05/10), p. 24	“System in Lockout/ Thermal Cutoff Device tripped”	Reset the gas control and check its cycling; replace the gas control; make sure the tank is completely filled with water
Induced draft gas valve LED: AP15696-3 (03/17), AP15696 (11/10), p. 28	“TCO limit lockout”	Reset the valve and check its cycling; make sure the tank is full of water
Gas valve LED, AP19361 (12/17): p. 32	“TCO limit lockout”, and a second “Four Flash” row: “Flame out of sequence”	As above; for flame out of sequence, replace the gas valve control

AP19361 (12/17) prints “Four Flash, three second pause” twice and has no five-flash row, so on heaters covered by that manual four flashes can be either fault (AP19361, p. 32). The power vent and powered damper LED tables sit under cautions about servicing controls (AP22511 Rev 02, p. 37; AP15756, p. 24); their resets and replacements are technician steps.

On the six-LED panels of some power vent and power direct vent models, the pattern ● ○ ○ ● ● ● is “ECO activated.”, fixed by replacing the gas control (AP17505-1, p. 35). On the Maximus display the ECO alarm is A016, “Energy Cutout (ECO) switch is open. This will disable the heater.” (AP21833 Rev 02, p. 43).

Rheem water heater 4 blinks: high water temperature limit tripped

What it means

Check these first

When to call a licensed technician

Notes for different models

Related Rheem gas tank water heaters codes

See also

Sources