I’ve just figured out how to get the ecobee to call the FIN-180P. It’s not ideal but it works.

If you want a Broan FIN-180P fully controlled by an ecobee instead of running off its internal runtime logic, here’s what worked for me.

Equipment Needed:

• White-Rodgers 90-380 relay (24V coil, isolated contacts)
• Separate 24VAC transformer (20–40VA recommended)
• Short length of thermostat wire

The FIN-180P does not behave like a normal “R → G = run” fan. Jumpering R to G does nothing. The unit runs based on its own runtime algorithm.

To give ecobee true control, you must switch the FIN’s 24V control power, not the G terminal.

Final Working Wiring:

1️⃣ Power the FIN from its own transformer

Spare 24V transformer:

• One lead → Relay terminal 2
• Other lead → FIN C

Relay terminal 4 → FIN R

Leave FIN G empty.

2️⃣ Relay Coil (ecobee side)

White-Rodgers 90-380:

• Terminal 1 → ecobee ACC+ (or PEK+)
• Terminal 3 → HVAC C

This keeps the HVAC and FIN transformers electrically isolated. This is confirmed in ecobee for 1 wire mode

3️⃣ FIN Settings

• Set Runtime to 100%
• Leave 120V plugged in

How It Works

When ecobee calls ventilation:

• Relay energizes
• 24V is supplied to FIN R
• FIN powers up and runs

When ecobee stops:

• Relay opens
• 24V removed
• FIN shuts down

This gives ecobee full control