Manual background

Fault

 

 

Lockout

 

Code

Description

Cause

Remedy

type

Displayed

 

 

 

 

 

 

 

E15

 

Blower speed is 200RPM

 

 

 

 

below the target speed for

 

 

 

 

20 seconds.

 

 

E16

 

Blower speed is 500RPM

 

 

 

 

above the target speed for 6

 

 

 

 

seconds.

Soft

1. Check the blower wire harness.

E17

Blower speed

Machine starts or normal

 

2. Change the blower.

 

abnormal.

combustion, but Blower

 

 

 

3. Change the board.

 

 

speed = 0 for last 3sec.

 

 

 

 

 

E18

 

Have Blower’s output signal

 

 

 

 

but the Blower speed = 0 for

 

 

 

 

last 400ms.

 

 

E19

 

Blower speed stuck > 3000

Soft

 

 

 

rpm

 

 

 

 

 

E20

Proportional

Proportional valve Current <

 

1. Check the proportional gas valve

 

Minimum.

 

wire harness.

 

valve (PV) current

Soft

E21

Proportional valve Current >

2. Change the board.

 

unusual.

Maximum.

 

3. Change the gas valve assembly.

 

 

 

E22

Outlet

Outlet Temperature

 

 

 

Temperature

is < minimum defined

 

 

 

Probe is Open

temperature.

 

 

 

circuit.

 

 

 

E23

Outlet

Outlet Temperature

 

 

 

Temperature

is > maximum defined

 

 

 

Probe is Short

temperature.

 

 

 

circuit.

 

 

 

E24

Inlet Temperature

Inlet Temperature is

 

1. Check temperature probes wire

 

Probe is Open

< minimum defined

Soft

harness.

 

circuit.

temperature.

2. Replace themperature probe.

 

 

E25

Inlet Temperature

Inlet Temperature

 

3. Change the board.

 

Probe is Short

is > maximum defined

 

 

 

circuit.

temperature.

 

 

E26

Tank Temperature

Tank Temperature

 

 

 

Probe is Open

is < minimum defined

 

 

 

circuit.

temperature.

 

 

E27

Tank Temperature

Tank Temperature

 

 

 

Probe is Short

is > maximum defined

 

 

 

circuit.

temperature.

 

 

E28

Ignition failure.

After a failure to detect

 

1. Check the igniter wire harness.

 

 

the flame during ignition,

 

2. Check igniter 120Vac voltage

 

 

the control will retry the

 

supply during the ignition time.

 

 

specified number of times.

 

3. Check the ignition rod. If it looks

 

 

After the maximum failed

Soft

dirty clean it using isopropyl alcohol

 

 

attempts, this fault is

 

and a clean cloth.

 

 

declared.

 

4. Check the high voltage wiring

 

 

 

 

connection between igniter and

 

 

 

 

igniter rod for proper contact.

E29

Outlet water

Outlet water temperature <=

 

1. Check the outlet temperature probe.

 

temperature too

(setting temperature – 15°C)

Alert

2. Change the board.

 

low.

for 60 seconds after flame

 

 

 

 

 

 

detected.

 

 

 

 

TABLE 5

 

 

www.hotwater.com

49

Page 49
Image 49
A.O. Smith HYB-90N warranty Fault, Lockout, Code, Description, Cause, Remedy, type, Displayed