Controller stuck showing tSt or TEST and does not operate solar heating normally.

Safety: Use caution when pressing buttons on a live controller; do not open the enclosure with power on.

• Exit test mode: Press and hold the MODE or EXIT button (per manual) for several seconds to leave test mode.
• Power-cycle: Turn off power for 30 seconds, then restore while not pressing any buttons. If tSt appears immediately, a switch or dip setting may be stuck.
• Inspect dip switches: With power off, open the controller and locate any configuration dip switches. Ensure the TEST or INSTALLER positions are set to NORMAL.
• Check keypad: Look for stuck or damaged buttons on the front panel. If a button is physically jammed, gently free it. If the keypad is defective, the front panel or entire controller may need replacement.