Transformers

Multi-tap 24 VAC control transformers — 40 VA and 50 VA, with 120/208/240 V primary taps for residential and light commercial HVAC control circuits.

2 products

CORALVOLT 24V 40VA HVAC Transformer, Multi-Tap 120/208/240V Input – Pack of 3 Save 16%

CORALVOLT 24V 40VA HVAC Transformer, Multi-Tap 120/208/240V Input – Pack of 3

Transformer

$47.50 $57.00
CORALVOLT 24V 50VA HVAC Transformer, Multi-Tap 120/208/240V Input – Pack of 3 Save 16%

CORALVOLT 24V 50VA HVAC Transformer, Multi-Tap 120/208/240V Input – Pack of 3

Transformer

$55.00 $66.00

Buying guide

Before you order a transformer

Choosing the right transformer

Size by VA, and do not undersize. The VA rating is the load the secondary can carry. Add up what the 24 V circuit actually drives — contactor coil, gas valve, condensate pump, thermostat, zone dampers — and pick a transformer above that total. A 40 VA unit suits a straightforward split system; add a humidifier, a zone panel or a smart thermostat with a C-wire and 50 VA gives you the headroom. An overloaded transformer runs hot, buzzes, and eventually fails open.

Match the primary tap to your line voltage. Multi-tap means one transformer covers 120 V, 208 V and 240 V supplies — you land the primary lead on the tap matching the incoming voltage and cap the ones you do not use. Landing 240 V on the 120 V tap destroys the transformer immediately.

Secondary is 24 VAC on all units here, the standard for thermostats and control circuits across virtually every North American residential system.

Signs a transformer has failed

A dead thermostat display with the breaker on, a contactor that will not pull in on a call, an audible buzz from the air handler, or a burnt-varnish smell around the control board. Check for 24 V across the secondary before condemning anything downstream — a failed transformer mimics a failed board.