TS-5: Troubleshooting Limit String

To access the “Limit String” screen from the home screen press the “Help” button followed by pressing the flashing “Fault Status” button. The next screen youn will have either “Soft Lockout” or “Hard Lockout” flashing along with the “Limit String Status”. Press the “Limit String Status” button and your next screen will have flashing boxes. The first box flashing is where the problem is. It may show a single limit or a group of limits. The rule here is when a limit is open all limits after that limit should be open. See picture below.

In this case either the thermal fuse or the sump pressure switch is open

Note: On the display these would be flashing

#B11

Is there a LWCO installed on the boiler?

#B24

Is the condensate trap flooded?

#B33

Is the boiler circulator running?

#B41

The air proving switch is connected to the gas valve with a rubber tube. When the display shows “Direct Ignition” the switch must see a negitive pressure for a short period. Remove the hose from the gas valve and verify the screw in the hose port is open at least 5 turns. Turn screw in all the way and back it out 5 turns. Did problem resolve?

#B51

Check for 24Vac at J6-3 on the Sage2 control. Is voltage present on J6-3?

#N33

Is there a lot of air noises in the heat exchanger?

#AR41

Is the Green or Amber lights on on the control

#H24

Do not unplug the connector from the low voltage board. Test the bottom left hole for 24Vac. Is 24Vac present?

#W24

Remove cap on the bottom of the trap and clean trap. Repair condensate line for proper drainage. Error removed?

No
#H33

Touch status on the display, than the left arrow button 2 times To display “Pump Status” Is the boiler circulator displayed as on?

#H41

Make sure there is no demand on the boiler for heat or DHW. Turn down the thermostat(s) and IWH aquastat. Is the fan running continuously?

#B61

Control is in a low water condition. Check pressure and water level in the boiler vrifying water level is above the probe. If there is water replace the control.

#N24

Measure voltage at the top External limit terminal on the 24Vac control. Is 24Vac present?

#AD24

Call Tech Services

#AC33

Disconnect the molex connector on the thermal switch on top of the heat exchanger. Test 24 Vac on the grey wire stamped 43a. Is there 24Vac present?

#U33

Blead the air out of the heat exchanger from the blead port on the top right of the heat exchanger.

#AX41

Unplug the harness from the flow switch. Meter the flow switch for continunity. Is the switch closed or open.

#BE41

Meter the red and white wires to the circulator for 120V. Is voltage available?

#N41

Press adjust 2 times, touch “Login”, touch zero’s in middle of the screen. Type in 86, press return key (bent arrow on the right) and press “Save”. Press “Adjust”. Press pump setup on the center left. Verify boiler pump is set for “any demand”.

#CH41

Turn the boiler off and remove the wires from the air proving switch. Meter the terminals where the wires were for continunity. Is the switch closed?

#K51

Measure voltage on the lower External limit terminal. Is voltage present?

#AJ24

Replace Jumper Plug.

#BV24

Meter the Thermal Switch for continunity. Is the switch open or closed?

#AH33

Replace wiring Harness.

#AO33

Verify the arrow on the flow switch is pointing down, away from the heat exchanger and parallel to the pipe. Installed properly?

#BN41

Replace Harness

#CD41

Change the circulator

#U41

Meter the Sage 2 control terminal marked J4-5 to “N” on the line voltage circuit board. Is there 120Vac present?

#AA41

Defective switch, replace air proving switch

#Q51

Test for 24Vac to J6-2 on the Sage 2 Control. 24Vac present?

#AW24

Are there CSD-1 controls installed on the External limit terminals or just the jumper.

#AP24

Replace switch.

#BT41

Remove and install properly. Switch installed properly?

Yes
#BX41

Replace the wiring harness

#AM41

Replace the Sage2 control

#AH41

Replace wiring harness

#BC24

Check voltage in and out of CSD-1 controls and reset or replace as needed.

#BO24

Check jumper for continunity and good connection to terminals. Replace or repair as needed.

#BH24

Call Tech Services

#J59

Trace back the orange wire from the condensate trap. There will be a Male and female connector just inside the swing open door. Pull the connectors apart. Does the boiler fire?

#AT33