Power is supplied to the unit, but the water does not heat. Follow these steps to troubleshoot the issue.
Step 1: First, check the fuse (if present) and verify that it has not blown. If the fuse is bad, replace it. If the fuse is in good condition or if the unit doesn’t have a fuse, move on to the next step.
Step 2: Remove the brew cones, warming deck, and front cover from the unit. Check to see if voltage is present at the heating elements when the unit is calling for heat. The meter should indicate approximately 208 to 240 VAC. If voltage is present, move on to the next step. If voltage is NOT present, jump to Step 5.
Step 3: Turn off power to the unit and disconnect the wire terminals from the heating element. Check the resistance of each of the heating elements.
Caution: Use the proper tools to avoid damaging the heating element. When reattaching the wires make sure to apply the proper torque to ensure the wires are attached properly.
For a 220 volt heating element:
- 4 Ω for a 2500 W heating element
- 8 Ω for a 3500 W heating element
- 8 Ω for a 3500 W heating element
For a 120 volt heating element:
- 9 Ω for a 1450 W heating element
- 0 Ω for a 1600 W heating element
If you have no continuity or infinite resistance (open), the heating element needs to be replaced.
Step 4: If the heating elements are good, check to see if the heating sensor has failed with it installed. You’ll need to turn off the power to the unit and disconnect the terminal plug from the heating sensor. If the water in the reservoir tank is hot, the resistance will be approximately 7 to 8 kΩ. If the water in the reservoir tank is cold, then the resistance should be 180 kΩ or less.
Step 5: If voltage was NOT present at the heating elements, check to see if the solid-state relay (SSR) has DC voltage. Measure between terminal 3 with the black lead and terminal 4 with the red lead. If 5 VDC is present, check the solid-state relay to see if it has failed. If voltage is not present, jump to Step 7.
Note: The unit may contain a triac instead of a solid-state relay. Details on testing the triac will be covered in Step 11.
Step 6: Now check the resistance at the solid-state relay. Turn OFF power to the unit and disconnect all wire connections to the SSR. Measure across terminals 1 and 2. If any resistance is present, replace the solid-state relay.
Step 7: If voltage was NOT present at the solid-state relay, remove top cover to gain access to the control module. Check to see if input voltage is present at the control module by measuring between terminal 18 and terminal 17. If voltage is present, make sure the control board is grounded properly and the connections are clean. Also, check for loose or bad wire connections. Replace the control module if it has failed
Step 8: If voltage is not present at the control module, check the high limit switch to verify it has not tripped open. If the high limit switch has tripped, reset it by pressing the reset button.
Step 9: If the high-limit switch has not tripped, determine if voltage is present on the output side of the high limit switch. Measure between terminal 2 and neutral on the high-limit switch. If voltage is not present, replace the high-limit switch.
Unit contains a triac instead of an SSR
Step 10: If the unit contains a triac instead of a solid-state relay, determine if 120 VAC is supplied from the high limit switch to anode 1 or A1 terminal. Place the black meter lead on the gate terminal and the red meter lead on line voltage A1. Approximately 120 VAC should be indicated on the meter.
Step 11: With the heating cycle activated from the control panel, place the black meter lead on neutral and the red meter lead on the gate terminal. Approximately 120 VAC should be displayed on the meter. If 120 VAC is present on the gate terminal when heat cycle is not activated, the control module may have failed and needs to be tested.
Step 12: To bench test the triac, turn off the power to the unit and disconnect the wires from the triac and place the meter leads on A1 and A2 to check resistance. If continuity (0 Ω) is indicated, replace the triac.
Step 13: If infinite resistance is indicated on the triac, short A2 terminal to the gate terminal, and measure resistance across A1 and A2 again with the meter leads. The meter should indicate between 40 and 100 Ω. If you have any other resistance, the triac needs to be replaced.