Specifications

Armstrong International
IOM-706
Flo-Direct Water Heater
Page 33 of 45
PLC I/Os
Troubleshooting
Problem Probable Cause Correction
High Temperature Fault
Contact Armstrong!
Do not operate
heater!
Water pressure switch failed and "dry fire"
start-up attempted
Check water pressure. If correct, replace pressure
switch. If not, continue.
Nozzles clogged Remove top plate and clean nozzles.
Tank Full Fault:
Pump not keeping up with
water production
Transfer pump throttling valve out of
adjustment
Readjust valve.
Transfer pump and/or bypass inoperable Check and repair or replace.
Downstream valves closed or restricted Confirm that all downstream valves are fully open.
Water Pressure Fault
Flow control valve restricted Open flow control valve.
Shut-off valve defective Repair or replace valve.
Restriction in inlet line Check filters and piping for obstructions.
Low system pressure Correct system pressure.
Modulating burner does
not enter automatic
mode and track set-point
("MANUAL" stays lit after
flame is established)
Reset button on Veri-Flame control is
pressed in
Press reset button on Veri-Flame control (button must
be in up position.
Inputs Outputs
0 Momentary start (auto or manual) 0 CR-A on; permission to start heater
1 Spark ignition on 1 Water supply on
2 Actuator in low fire position 2 Transfer pump on
3 Water pressure switch 3 Transfer bypass on
4 Storage tank full (auto stop) 4 Water pressure switch fault
5
Lower canister bottom float switch
(transfer pump off)
5 Lower canister full fault
6
Lower canister second float switch
(transfer pump on, bypass off)
6 Actuator switch fault
7
Lower canister third float switch
(bypass on)
7 General alarm
8
Lower canister float top float switch
(tank full fault)
9 Flame detected (main fuel supply on)
The following PLC inputs and outputs are shown to facilitate more advanced troubleshooting.
PLC I/Os