Steffes HPB22 Troubleshooting Guide - Manual (Page 4)

Page 2
Heat Pump Booster
Function: Core Charging
Problem: Unit undercharges
Before starting any of the procedures below, check voltage on load side of all HPB circuit
breakers. Check for 24 VAC between each of the 3-amp low voltage fuses and the "C" position
(thermostat connection) on the charge control circuit board's terminal block.
Check charge control thermostat
knob for proper position.
Check daily kWh usage. (See
Unit Specifications in Appendix
of the Owner's Manual.)
Set the charge level selector switch on the charge
control board (51) to the "HIGH" position. Check
for proper amperage draw on heating elements (18):
(Thiswill very slightly)
HPB11B = 46 AMPS (240V systems)
HPB15B = 61 AMPS (240V systems)
HPB22B = 92 AMPS (240V systems)
Unit undercharges
on warm days
Less than
Max usage
Check unit sizing.
Proper Maximum
Usage
With the charge level selector
switch still in the "HIGH"
position, check for zero voltage
on charge control resistor (49)
from both the center to bottom
and the center to top.
Check for 24 VAC on base
terminals of all charging
sequencers (58).
Ok
Less than
proper amperage
Place the charge control circuit
board switches in "WINTER"
and "AUTO". Disconnect
outdoor air sensor "W" wire.
No Voltage
Replace charge control
circuit board (51).
Voltage
Check for
contact closure
on all charging
sequencers (58).
Voltage
Replace
sequencer (58).
Check heating
elements (18).
Ok
Open
All Three
Outdoor
Temperature
Lights On
Check outdoor air
temperature sensor in
cold place (less than 15
degrees F). All mercury
bulbs should open.
Replace charge control
circuit board (51).
Not All
Outdoor
Temperature
Lights On
Replace outdoor air
temperature sensor (61). Replace charge control
thermostat (53).
All bulbs closed
All bulbs
open
Replace charge
control circuit
board (51).
Defective
Unit undercharges
on cold days
No
Voltage
Check the outdoor temperature
lights on charge control circuit
board (51). All three must be on.
Ok
Check unit
wiring and/or
replace charge
control circuit
board (51).
Page 3
Check charge control thermostat
knob for proper position.
Check daily kWh usage.
(See Unit Specifications.)
Set the charge level selector switch on the charge
control board to the "HIGH" position. Check for
proper amperage draw on heating elements:
(Thiswill very slightly)
HPB11B = 46 AMPS (240V systems)
HPB15B = 61 AMPS (240V systems)
HPB22B = 92 AMPS (240V systems)
Unit undercharges
on warm days
Less than
Max usage
Check unit sizing.
Proper
Maximum
Usage
With the charge level selector
switch still in the "HIGH"
position, check for zero voltage
on charge control resistor from
both the center to bottom and the
center to top.
Check for 24VAC on base
terminals of all charging
sequencers.
Less than
proper amperage
Place the charge control circuit
board switches in "WINTER"
and "AUTO". Disconnect
outdoor air sensor "W" wire.
No Voltage
Replace charge control
circuit board.
Voltage
Check for
contact closure
on all charging
sequencers.
Voltage
Replace
sequencer(s).
Check heating
elements and replace
as necessary.
Ok
Open
All Three
Outdoor
Temperature
Lights On
Check outdoor air
temperature sensor in
cold place (less than
15

F). All mercury
bulbs should open.
Not All
Outdoor
Temperature
Lights On
Replace outdoor air
temperature sensor. Replace charge control
thermostat.
All bulbs closed
All bulbs
open
Defective
Unit undercharges
on cold days
No
Voltage
Check the outdoor temperature
lights on charge control circuit
board. All three must be on.
Ok
Check unit
wiring and/or
replace charge
control circuit
board.
Ok