Error Code 24; Error Code 29 - Rheem 862 27 Series Service Instructions Manual

Error Code 24

Malfunction of Operational Switch. At a minimum check the following:
1 If fitted, disconnect remote temperature control and retry.
2 Verify unit is electrically earthed. Do not use a 2 prong electrical adapter on the power
cord.
3 Check for presence of return circulation pump in the system. Any water flowing through
the unit prior to turning unit ON may cause error code 24.
Error Code 24
Is the Min or Max button
depressed?
TEST 16
NO
Replace the control PCB.
SW1
Ensure the min/max
buttons are not depressed.

Error Code 29

Heat exchanger outlet temperature is too low.
Error Code 29
Measure the hot water outlet
temperature
Display maintenance information
'5y' on remote control
Does the measured hot water
temperature match that
indicated by 5y?
YES
Check heat exchanger for
blockage/restriction (possible
scale build-up). Ensure air inlet is
clear and free of debris
TM049 27L Continuous Flow Service Instructions
REV AL – Issued April 2019
This document is stored and maintained electronically by Rheem Technical Support. All printed copies are deemed "uncontrolled".
ON
DIP1
OFF
1 2 3 4
ON
DIP2
OFF
1 2 3 4
SW2 SW3
Is the resistance of the heat
exchanger thermistor normal?
Is the resistance of the hot
NO outlet thermistor normal?
YES
Test 16
Are the controller cables or any other
cables/components inadvertently depressing
the Min/Max or Adjuster buttons on PCB?
YES
NO
TEST 15
YES
NO
TEST 15
Release the Min/Max button.
Replace PCB
Replace heat exchanger
thermistor
Replace hot outlet thermistor
Check the burner pressure and
adjust if necessary.
Refer to section on burner
pressure adjustment
53