How do I verify if the relay is energized

this 4-way reversing valve is often the culprit

Engineered specifically for 2-way normally closed configurations with a push-down-to-open action

it is designed for a direct fit into existing Mustang control panel housings

3/8" x 4" Bulb

Tekmar Controls 403 Control 324846-701 How do I verify ifThe Tekmar Controls 403 is a sophisticated 24Vac tN2 House Control designed for multi zone hydronic systems requiring high precision management of outdoor temperature reset and indoor temperature feedback. This microprocessor based hub effectively coordinates boiler control, domestic hot water (DHW), and mixing valve operations through a centralized tekmarNet 2 bus. Built to drive up to 4 zone pumps on board, the 403 supports single stage, two stage,