Description
Product image is representative only. Actual product may differ in appearance depending on size, configuration, and options selected at order.
CSA-certified motorized round flue control damper for fuel-burning appliance vent and flue runs, 4"–9". Power Close / Spring Open on every unit — closes when powered, springs open on any power loss, keeping the flue clear when the electrical system fails. Relay and end switch included on every unit. Select size only.
Do not substitute a standard HAC on a flue application. A standard HAC with Power Open / Spring Close action fails closed on power loss — sealing the flue while the appliance is firing. On a gas or oil appliance, a closed flue during operation creates carbon monoxide accumulation and back-draft risk. The HAC-F SPC-F actuator is selected specifically because it fails open. The flue is always clear on any power interruption.
✓ Spring Open fail-safe — always — if power is lost while the appliance is firing, the spring opens the damper and the flue is clear; no control system, no signal, no electricity required
✓ Relay and end switch included on every unit — a flue damper without interlock capability is an incomplete safety installation; relay and end switch are not optional on the HAC-F
✓ CSA certified — complete assembly — the HAC-FS is not an acceptable substitute on code-required applications; AHJ will verify certification
✓ Select size only — 4" through 9"; action, relay, and end switch are pre-configured on every unit; no configuration errors possible
✓ Patented Hoyme spring motor drive — stall-protected, nylon bearings; engineered for the mechanical stresses of a flue run application
Why Power Close / Spring Open — not Power Open / Spring Close
The HAC-F is at rest in the spring-open position — flue clear — when there is no power. When the appliance calls to fire, 24 Vac closes the damper to reduce standby heat loss. If power is interrupted at any point, the spring immediately opens the damper. The fail-safe is always in the direction of a clear flue. A Power Open / Spring Close damper is the opposite — it fails closed, sealing the flue during a power interruption while the appliance may still be firing.
1
Appliance calls to fire — ADP relay adaptor receives the call signal from the appliance safety circuit
2
HAC-F de-energizes — spring opens the damper; flue path is clear
3
End switch confirms open position — signal returns to ADP relay adaptor confirming flue is clear
4
ADP releases appliance safety circuit — appliance fires; if end switch does not confirm, appliance stays off
5
Appliance call ends — ADP energizes HAC-F (Power Close), damper closes to reduce standby heat loss through the flue
Fail-Safe Direction
Spring Open — flue always clear on power loss
Sizes
4"–9"
Voltage
24 Vac
Action
Power Close / Spring Open (SPC-F)
Included
Relay + end switch — every unit
Certification
CSA certified
Select the correct ADP relay adaptor for your appliance
Gas furnace — millivolt / standing pilot system (250mVdc–100Vdc) ADP-0MV2-S5A
Gas furnace — 24 Vac system ADP-0240-S5A
Boiler or tankless water heater — 110 Vac system ADP-1102-S5A
Need sizes 10"–30"? See the HAC-F Large Diameter listing — Belimo TFB24 actuator, same SPC-F spring-open fail-safe, for commercial flue applications. For non-permitted applications where CSA certification is genuinely not required by the AHJ, see the HAC-FS. Never substitute HAC-FS on a code-required installation.
2-year electrical · 10-year mechanical warranty
CSA certified · Made in Canada · Interlock required — always