Ruud 29

What does Ruud 29 mean?

On Ruud RUTGH condensing tankless water heaters, error code 29 means the water heater is overheating. The controller monitors temperature and shuts the unit down when it exceeds safe operating limits, displaying code 29 to protect the heat exchanger and prevent dangerous scalding-temperature water.

Symptoms

• 29 shown on the remote control LED display
• Heater shuts down during operation
• No hot water after the fault
• Possible very hot water just before shutdown

Common causes

• Internal overheating beyond safe operating temperature
• Restricted water flow or circulation issue
• Scale or blockage reducing heat transfer

Diagnostic steps

1. 01

   Turn off the hot water faucets

   Turn off all hot water faucets and allow the unit to cool before doing anything else.

2. 02

   Power-cycle the heater

   Turn off the heater, unplug it for about 30 seconds, plug it back in, restart, then turn on a hot water faucet and recheck the display.

3. 03

   Note the code if it persists

   If 29 stays displayed, record the code for the service technician.

4. 04

   Contact a dealer or qualified service technician

   The manual's solution for code 29 is to contact a dealer or qualified service technician, as overheating is a safety condition.

When to call a professional

Treat code 29 as a safety shutdown and call a dealer or qualified service technician if it does not clear with a power cycle. Overheating can produce scalding water; the manual warns that water above 125F can cause death or severe burns and that the unit has a device to shut off gas when it exceeds normal operating temperatures. Do not attempt internal repairs of safety devices yourself.