A.O. Smith BTH 300A Manuale Utente

19

Display Flashes “05” when button is pressed:

Display Flashes “15” when button is pressed:

Display Flashes “25” when button is pressed:

ECO LED Flashing:

ECO SWITCH OPEN, ECO LED Flashing

CONTROL BAD. See Figure 22.
All LEDs Flashing:

1. This indicates the control has

1. Press button on the

failed on of its internal

display board to reset

diagnostic self-tests.

control.  If this error
occurs repeatedly,
replace control.

CONTROL BAD, All LEDs Flashing

COMBUSTION AIR BLOCKAGE. See Figure 23.
Pressure Switch LED Flashing:

COMBUSTION AIR BLOCKAGE, Pressure Switch LED Flashing

1.  Temperature Probe wiring

1. Repair Wiring

open

2. Defective probe

2. Replace probe

1.  No water in tank and tank

1. The symptom does not

in freezing conditions

reflect a control problem

2. Water in tank above freezing

2. Temperature probe out of

tolerance, replace temp.
probe

1.  Water in tank is low, probe

1. Fill tank

immersed in steam

2. Probe wiring shorted

2. Repair wiring

3. Defective probe

3. Replace probe

1.  Temp. Probe unplugged

1. Check connectors

2. Temp. probe wiring damaged

2. Repair wiring

3. Water in tank too hot

3. Normal condition when

water t e m p e r a t u r e
exceeds safety limit.
Allow water to cool or
admit water into tank and
manually reset the control.
Determine cause for
overtemp condition.

1. Combustion air blocked

1. Check exhaust piping and
flue for obstructions

2. Blower not operating:

2. a. Repair wiring

a. Check blower wiring

b. Replace blower motor

b. Check blower motor

3. Defective air switch

3. Replace air switch

4. Pressure switch jumped out

4. This controller must  sense

an open contact on the
blower proving airflow
switch before the blower
comes on. Check to see if
blower proving airflow
switch is still connected to
the unit.