Solenoid Troubleshooting - Universal

Solenoid Troubleshooting - Universal

Field technicians guide for troubleshooting solenoid valves.


AlertSLAYER recommends all service be performed by an experienced SLAYER Espresso trained technician. For a technician reference near you, please contact SLAYER Support at (206)-284-7171 (#1 in Directory) or email support@slayerespresso.com.


Solenoid valves are common place on nearly every make and model of espresso machine. SLAYER Espresso machines feature 2-way & 3-way, 24vDC*, solenoid valves which perform a variety of functions: water & steam delivery, unique brewing feature activation, and fill sequences.

*Espresso V3 features an AC solenoid for steam fill. The only AC solenoid across the product lineup.

Objective:
Diagnose signal circuit and determine solenoid functionality. There are several ways to troubleshooting solenoid faults. In this guide, experience with SLAYER Espresso machines and a multimeter is imperative as the guide demonstrates two ways to test voltage at the solenoid. Testing voltage at the solenoid indicates to the technician that the signal circuit is functioning and the solenoid should be responding to input voltage. 

Symptoms:
  1. No water through group.
  2. Unique brewing feature (Pre-Brew / Pre-Infusion to Full-Brew) not activating.
  3. No steam (Steam Series only).
  4. Steam tank either overfilling or not filling.
  5. Leaking group (through dispersion screen & screw).

Tools:
  1. Multimeter
  2. #1 Philips Head Screwdriver
  3. #2 Philips Head Screwdriver
Parts:
  1. Contact SLAYER Support or visit the diagrams below for part identification:
    1. SLAYER Parts Diagrams



24vDC Solenoid Troubleshooting:

Idea
The following troubleshooting measures are demonstrated on a brew valve for a Steam EP while the machine is powered ON. All concepts detailed in this guide apply across models and valves such as: steam valve (Steam Series), Pre-Infusion valve (LP), Needle Valve (Espresso Series), hot water mix valve, and autofill valve* . Understanding SLAYER signal circuit functionally is necessary prior to troubleshooting. *Not applicable to Espresso V3 autofill solenoid.

Step 1 - Identify Issue & Isolate Valve:
In this scenario, lets pretend Group 1 is not dispensing water while the brew button is activated. Yet the pump is ON and the display timer is counting UP on the display. This indicates that the input (user activated) functions are working however the brew circuit is not engaging. Since the 3-way brew solenoid is the main gate for water dispensed through the group we may suspect the brew valve is at fault. 

Step 2 - Remove Solenoid Electrical Boot:
  1. Using a small philips head screwdriver.
  2. Loosen and remove electrical boot.
  1. Once attachment screw has been removed.
  2. Separate rubber grommet from boot.
    1. (Careful not to lose either of these, they are not offered as a spare part!)
  1. Unscrew harness nut (orange circle) from electrical boot.
  2. This will allow for terminal exposure.


Step 3 - Test DC Voltage:
This step can be done in one of two ways.
  1. Reattaching the electrical terminal to the solenoid or leaving the terminal loose.
    1. SLAYER recommends reattaching electrical terminal to solenoid.

  2. Once attached, place multimeter leads on wires.
  3. Reminder, all SLAYER brew valves are 24vDC! Set multimeter to DC.
  1. With multimeter leads on the terminal screws.
  2. Activate any brew button for Group 1.
  3. 24vDC should be present.
    1. If 24vDC is NOT present.
      1. Contact SLAYER Support for further troubleshooting.
    2. If 24vDC IS present, yet solenoid does not 'click' and no water dispenses through group:
      1. Inspect/rebuild or replace solenoid.


Espresso V3 Brew & Needle Valve Solenoid Troubleshooting:
V3 models feature individual group 'harnesses' or 'bundles' which contain signal circuits for each group. Unlike the troubleshooting measure demonstrated above. Each solenoid has its own Mini-Molex JR connection to simply disconnect and verify voltage at.

Step 1 - Identify Issue & Isolate Valve:
In this scenario, Group 1 is not switching from Pre-Brew to Full-Brew despite actuating group to the far left, Full-Brew, position. Since the Needle Valve solenoid controls the change between low and full flowrate through the brew circuit. We can suspect the Needle Valve may be at fault.

Step 2 - Disconnect Needle Valve Molex:
  1. The Needle Valve Molex is located among the bundle harness.

Step 3 - Test DC Voltage:
  1. Set multimeter to DC.
  2. Place leads on female side of molex.
    1. Female side of molex threads down the the Mechanical Relay which receives a signal from the magnetic reed switches at the group head!
  3. Actuate to Full-Brew: 24vDC should be present.
    1. If 24vDC is NOT present.
      1. Contact SLAYER Support for further troubleshooting.
    2. If 24vDC IS present but brew phases do not change.
      1. Inspect/rebuild or replace solenoid.


Resources & Additional Troubleshooting:
  1. Pre-Infusion Solenoid Troubleshooting - Steam LP
  2. Magnet Switch:
    1. Adjustment
    2. Troubleshooting:
      1. Steam LP
      2. Espresso V3
  3. Barrel Switch (Steam Series) Troubleshooting
Alert
SLAYER recommends all service be performed by an experienced SLAYER Espresso trained technician. For a technician reference near you, please contact SLAYER Support at (206)-284-7171 (#1 in Directory) or email support@slayerespresso.com.


Questions or concerns? Please contact support@slayerespresso.com or call 206 284 7171 (#1 in Directory).

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