If the heater wires are not the problem then it could be that the heater relay chip is faulty.

You can check this by watching the video, “Testing Computer Relays.”

Video Overview: How to Determine if a Freeze Dryer Relay is Faulty

The video provides a guide on diagnosing issues with relays in a Harvest Right freeze dryer. It walks through how to perform functional tests to isolate faulty relays.

Steps:

1. Unplug & Remove Panels – Unplug the freeze dryer and take off the outer panels.

2. Access Test Screens – Power on and go to test mode or factory setup screens to control components.

3. Test Drain Valve – Try turning on drain valve. If it doesn't click or light up, firmware likely needs an update from tech support.

4. Test Suspected Component – Turn on the component not working properly (e.g. vacuum pump) and check if the corresponding relay clicks and illuminates.

5. Re-Route Wires – If relay engages but component doesn't activate, disconnect wires from relay and connect them to the drain valve relay.

6. Retest Component – Turn on drain valve relay. If component now activates, it indicates the original relay is faulty.

7. Contact Support – Call tech support to request a new relay board if diagnosis confirms the relay is bad.

By following this guide, users can efficiently diagnose if a relay issue is causing problems with their Harvest Right freeze dryer, saving both time and resources.