Direct to Homeowners
1-778-759-9864
Canada (CAD $) flagCanada (CAD $)
BCFurnace

Furnace Transformers & Relays

We sell directly to the homeowner

The transformer steps 120V line voltage down to the 24V control voltage that runs the thermostat, gas valve, and board logic. Relays and contactors let that low-voltage circuit switch line-voltage loads. When a furnace is completely dead with no lights on the board, the transformer is one of the first things to check.

253 transformers & relays in stock, ready for same-day pickup at our Coquitlam warehouse or shipped worldwide.

Signs your transformer may have failed

  • Furnace completely dead — no board LED, no thermostat display
  • Thermostat blank or unresponsive on a hardwired system
  • Transformer buzzing loudly, running hot, or smelling burnt
  • Blower or condenser will not engage despite a valid call

Not sure which part you need? Call 1-778-759-9864 with your furnace model number and we will confirm it before you order.

Shop transformers & relays by brand

York118Lennox57Carrier33Ruud30American Standard14Goodman10

Transformers & Relays we stock

LENNOX RELAY, DPDT, 24 VOLT, 13 AMP Electrical, Transformers, Relay furnace part

LENNOX RELAY, DPDT, 24 VOLT, 13 AMP

Part #: 000-007
In Stock
CA$67.27
LENNOX TIME DELAY RELAY, 24 VOLT, ON DELAY 1 SECOND, OFF DELAY 45 SECOND Electrical, Transformers, Relay furnace part

LENNOX TIME DELAY RELAY, 24 VOLT, ON DELAY 1 SECOND, OFF DELAY 45 SECOND

Part #: 000-073
In Stock
CA$129.02
LENNOX RELAY, 24VAC COIL, DPDT Electrical, Transformers, Relay furnace part

LENNOX RELAY, 24VAC COIL, DPDT

Part #: 000-159
In Stock
CA$85.81
LENNOX 104772-01 DELAY RELAY Electrical, Transformers, Relay furnace part

LENNOX 104772-01 DELAY RELAY

Part #: 000-167
In Stock
CA$79.84
LENNOX RELAY, 3PDT, 24V Electrical, Transformers, Relay furnace part

LENNOX RELAY, 3PDT, 24V

Part #: 000-169
In Stock
CA$108.07
LENNOX TRANSFORMER / RELAY 120 TO 24VAC, 50/60HZ, 40VA Electrical, Transformers, Relay furnace part

LENNOX TRANSFORMER / RELAY 120 TO 24VAC, 50/60HZ, 40VA

Part #: 000-205
In Stock
CA$256.64
LENNOX BLOWER RELAY, DPST Electrical, Transformers, Relay furnace part

LENNOX BLOWER RELAY, DPST

Part #: 000-231
In Stock
CA$170.04
LENNOX SOLID STATE RELAY, TIME DELAY, 1 SECOND ON/8 SECOND OFF, 24VAC Electrical, Transformers, Relay furnace part

LENNOX SOLID STATE RELAY, TIME DELAY, 1 SECOND ON/8 SECOND OFF, 24VAC

Part #: 000-310
In Stock
CA$168.37
LENNOX RELAY & TRANSFORMER, 120 TO 24V, 40VA FAN CENTRE Electrical, Transformers, Relay furnace part

LENNOX RELAY & TRANSFORMER, 120 TO 24V, 40VA FAN CENTRE

Part #: 000-376
In Stock
CA$563.73
LENNOX SEQUENCER/RELAY, 24V, NORMALLY OPEN, DPST Electrical, Transformers, Relay furnace part

LENNOX SEQUENCER/RELAY, 24V, NORMALLY OPEN, DPST

Part #: 000-398
In Stock
CA$125.91
LENNOX RELAY, 24 VOLT, SPST Electrical, Transformers, Relay furnace part

LENNOX RELAY, 24 VOLT, SPST

Part #: 000-407
In Stock
CA$66.33
LENNOX RELAY, 24 VOLT COIL, 3PDT Electrical, Transformers, Relay furnace part

LENNOX RELAY, 24 VOLT COIL, 3PDT

Part #: 000-424
In Stock
CA$88.66
LENNOX TRANSFORMER, 208/240 VOLT, 70VA Electrical, Transformers, Relay furnace part

LENNOX TRANSFORMER, 208/240 VOLT, 70VA

Part #: 000-425
In Stock
CA$155.54
LENNOX RELAY, DPDT, 24 VOLTS Electrical, Transformers, Relay furnace part

LENNOX RELAY, DPDT, 24 VOLTS

Part #: 000-430
In Stock
CA$101.05
LENNOX IGNITION TRANSFORMER, 120V 60HZ 40VA PRIMARY, 20KV 40MA SECONDARY Electrical, Transformers, Relay furnace part

LENNOX IGNITION TRANSFORMER, 120V 60HZ 40VA PRIMARY, 20KV 40MA SECONDARY

Part #: 000-441
In Stock
CA$546.18
LENNOX RELAY, 24 VOLT, 50/60HZ, SPST, NORMALLY OPEN Electrical, Transformers, Relay furnace part

LENNOX RELAY, 24 VOLT, 50/60HZ, SPST, NORMALLY OPEN

Part #: 000-471
In Stock
CA$73.35
LENNOX RELAY, 208-240 VOLT, DEFROST Electrical, Transformers, Relay furnace part

LENNOX RELAY, 208-240 VOLT, DEFROST

Part #: 000-477
In Stock
CA$541.79
LENNOX OVERLOAD PROTECTOR/BLOWER RELAY, 1.6/2.5A, 690V, 1PH Electrical, Transformers, Relay furnace part

LENNOX OVERLOAD PROTECTOR/BLOWER RELAY, 1.6/2.5A, 690V, 1PH

Part #: 000-530
In Stock
CA$232.51
LENNOX TIME DELAY RELAY, 24V, DPST Electrical, Transformers, Relay furnace part

LENNOX TIME DELAY RELAY, 24V, DPST

Part #: 000-567
In Stock
CA$67.56
LENNOX RELAY, SPDT, 120V COIL Electrical, Transformers, Relay furnace part

LENNOX RELAY, SPDT, 120V COIL

Part #: 000-569
In Stock
CA$38.28
LENNOX POTENTIAL RELAY, 332V 60HZ COIL Electrical, Transformers, Relay furnace part

LENNOX POTENTIAL RELAY, 332V 60HZ COIL

Part #: 000-572
In Stock
CA$61.99
LENNOX POTENTIAL RELAY Electrical, Transformers, Relay furnace part

LENNOX POTENTIAL RELAY

Part #: 000-657
In Stock
CA$51.09
LENNOX SEQUENCER RELAY, 24 VOLT, NORMALLY OPEN Electrical, Transformers, Relay furnace part

LENNOX SEQUENCER RELAY, 24 VOLT, NORMALLY OPEN

Part #: 000-716
In Stock
CA$126.78
POTENTIAL RELAY, SP N.C., 132-148 VOLTS Electrical, Transformers, Relay furnace part

POTENTIAL RELAY, SP N.C., 132-148 VOLTS

Part #: 000-739
In Stock
CA$104.32
Time Delay Relay, Triple Stacked, 24 Volt, On 1-110 Second, Off 1-110 Second Electrical, Transformers, Relay furnace part

Time Delay Relay, Triple Stacked, 24 Volt, On 1-110 Second, Off 1-110 Second

Part #: 000-852
In Stock
CA$115.18
Relay, 240 Volt, DPDT Electrical, Transformers, Relay furnace part

Relay, 240 Volt, DPDT

Part #: 000-854
In Stock
CA$125.05
Thermal Sequencer Relay, 24 Volt, DPDT, Normally Open Electrical, Transformers, Relay furnace part

Thermal Sequencer Relay, 24 Volt, DPDT, Normally Open

Part #: 000-867
In Stock
CA$228.12
Relay, 24 Volt Coil, 5 Amp, DPDT Electrical, Transformers, Relay furnace part

Relay, 24 Volt Coil, 5 Amp, DPDT

Part #: 000-868
In Stock
CA$77.52
LENNOX RELAY, BLOWER, 24 VOLT, 15 AMP, 3PDT Electrical, Transformers, Relay furnace part

LENNOX RELAY, BLOWER, 24 VOLT, 15 AMP, 3PDT

Part #: 001-098
In Stock
CA$144.90
LENNOX RELAY, 22 VOLT DC, DPST, NORMALLY OPEN Electrical, Transformers, Relay furnace part

LENNOX RELAY, 22 VOLT DC, DPST, NORMALLY OPEN

Part #: 001-099
In Stock
CA$140.93
LENNOX RELAY, 24 VOLT COIL, 10 AMP, DPDT Electrical, Transformers, Relay furnace part

LENNOX RELAY, 24 VOLT COIL, 10 AMP, DPDT

Part #: 001-103
In Stock
CA$110.97
LENNOX THERMAL SEQUENCER RELAY, 24 VOLT, DPDT, NORMALLY OPEN Electrical, Transformers, Relay furnace part

LENNOX THERMAL SEQUENCER RELAY, 24 VOLT, DPDT, NORMALLY OPEN

Part #: 001-123
In Stock
CA$173.05
LENNOX RELAY, DPDT, 24VOLTS Electrical, Transformers, Relay furnace part

LENNOX RELAY, DPDT, 24VOLTS

Part #: 001-181
In Stock
CA$119.39
LENNOX RELAY, DPDT, 24VAC COIL Electrical, Transformers, Relay furnace part

LENNOX RELAY, DPDT, 24VAC COIL

Part #: 001-187
In Stock
CA$51.59
LENNOX RELAY, BLOWER, ICE CUBE, 24VAC, SPDT Electrical, Transformers, Relay furnace part

LENNOX RELAY, BLOWER, ICE CUBE, 24VAC, SPDT

Part #: 001-189
In Stock
CA$70.72
LENNOX TIME DELAY RELAY, 6-600 SEC INTERVAL DEL Electrical, Transformers, Relay furnace part

LENNOX TIME DELAY RELAY, 6-600 SEC INTERVAL DEL

Part #: 001-209
In Stock
CA$195.24
LENNOX TIME DELAY RELAY, ON 6-600 SEC, 24 VAC Electrical, Transformers, Relay furnace part

LENNOX TIME DELAY RELAY, ON 6-600 SEC, 24 VAC

Part #: 001-210
In Stock
CA$195.24
Transformer, 200/230V to 24V, 60HZ, 75VA Electrical, Transformers, Relay furnace part

Transformer, 200/230V to 24V, 60HZ, 75VA

Part #: 020-001
In Stock
CA$173.29
Transformer, 120 to 24V, 60HZ, 35VA Electrical, Transformers, Relay furnace part

Transformer, 120 to 24V, 60HZ, 35VA

Part #: 020-004
In Stock
CA$144.77
Relay Board, Time Delay, 24 Volt Coil, 60HZ Electrical, Transformers, Relay furnace part

Relay Board, Time Delay, 24 Volt Coil, 60HZ

Part #: 020-010
In Stock
CA$204.00
RELAY, 240/480V, 24V COIL Electrical, Transformers, Relay furnace part

RELAY, 240/480V, 24V COIL

Part #: 020-059
In Stock
CA$65.80
RELAY, START, SPST, 35 A COIL, 204V PICK Electrical, Transformers, Relay furnace part

RELAY, START, SPST, 35 A COIL, 204V PICK

Part #: 020-060
In Stock
CA$59.22
RELAY; TIME DELAY, SPST, 3 MIN, 1A, 120V Electrical, Transformers, Relay furnace part

RELAY; TIME DELAY, SPST, 3 MIN, 1A, 120V

Part #: 020-061
In Stock
CA$220.01
RELAY, START, SPST, 50 A COIL Electrical, Transformers, Relay furnace part

RELAY, START, SPST, 50 A COIL

Part #: 020-097
In Stock
CA$59.22
TRANSFORMER; 40VA, 200/230V PRI, 24V SEC Electrical, Transformers, Relay furnace part

TRANSFORMER; 40VA, 200/230V PRI, 24V SEC

Part #: 020-560
In Stock
CA$93.71

Image coming soon

000-250

LENNOX 01 RELAY, DPDT AND 4PDT, 24 VOLTS

Part #: 000-250
In Stock
CA$97.41

Image coming soon

020-172

TRANSFORMER; 40VA, 120V PRI, 24V SEC

Part #: 020-172
In Stock
CA$123.23

Image coming soon

020-274

RELAY, SPST, 20A, 24 VDC COIL

Part #: 020-274
In Stock
CA$134.36

Showing 48 of 253. Pick your brand above for the full list, or browse every part by number.

Transformers questions

How do I test a transformer?
Confirm 120V arrives at the primary, then measure the secondary — it should read roughly 24 to 28V AC. Line voltage in with no low voltage out means the transformer has failed. Check for a short in the low-voltage wiring first, though, because a shorted thermostat wire is a common cause of a repeatedly blown transformer.
What rating do I need?
Match the VA rating and both voltages. A 40VA transformer is typical for a furnace with air conditioning; going smaller than the original will overheat under load. Match the mounting style too.

Need it today in Greater Vancouver?

Call ahead and we will set the part aside at the Coquitlam counter. No account, no trade card, no minimum order.

1-778-759-9864Pickup details