CAT Block Heaters: C15, C13, C7, 3406 & 3306
Nearly every on-highway CAT — C10 through C16, 3176 through 3406E — takes its coolant heater in the oil cooler, replacing a threaded plug in the cooler bonnet. That makes CAT one of the easiest heavy-duty installs: no freeze plugs to punch out, just a pipe plug to swap for an element. The catch is that the port size changed across generations (1" NPT, then 1-5/16", then 1-3/16"), so the year and ACERT designation matter.
The mid-range engines are the exception: the C7 and its 3126/3116 ancestors use a 44 mm freeze-plug heater in the block, and the old 3208 offers both styles. All part numbers below are Zerostart / Phillips & Temro, with Kat's equivalents where the catalogs agree.
Heater part numbers by application
Part numbers from the Zerostart / Phillips & Temro heavy-duty application guide, with Kat's equivalents where both catalogs list the engine. Numbers are occasionally superseded — confirm against a current catalog or dealer before ordering.
C13 ACERT & C15 ACERT (2007 and newer)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500111 | 1,500 W | 120 V | 1-3/16" STOR | Immersion | 3600008 |
Replaces the 1-3/16" plug in the rear of the oil cooler, right-hand side of the engine.
Kat's equivalent: 30216 (1,500 W / 120 V).
C9, C15, C16 ACERT (2004–2006)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500077 | 1,500 W | 120 V | 1-3/16" thd | Immersion | 3600008 |
| 3500076 | 1,500 W | 240 V | 1-3/16" thd | Immersion | 8608377 |
Replaces the 1-3/16" threaded plug in the rear of the oil cooler bonnet.
Kat's equivalent: 30213 (1,500 W / 120 V).
C11 & C13 ACERT (2004–2006)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500075 | 1,500 W | 120 V | 1-5/16" STOR | Immersion | 3600008 |
| 3500074 | 1,500 W | 240 V | 1-5/16" STOR | Immersion | 8608377 |
Replaces the 1-5/16" threaded plug in the rear of the oil cooler.
Kat's equivalents: 30212 (120 V) / 31212 (240 V).
C9, C15, C16 (pre-ACERT), 3408
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 8600090 | 1,000 W | 120 V | 1" NPT | Immersion | 3600008 |
| 8600120 | 1,000 W | 240 V | 1" NPT | Immersion | 8608377 |
| 8605556 | 1,500 W | 120 V | 1" NPT | Immersion | 3600008 |
| 8600260 | 1,500 W | 240 V | 1" NPT | Immersion | 8608377 |
Installs in the oil cooler rear bonnet.
Kat's equivalents: 30313/31313 (1,000 W) and 30303/31303 (1,500 W).
C10, C12, 3196; 3406 with BrakeSaver (1994+)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500013 | 1,500 W | 120 V | 1" NPT | Immersion | 3600008 |
| 3500031 | 1,500 W | 240 V | 1" NPT | Immersion | 8608377 |
Replaces the 1" NPT plug in the oil cooler (rear on C10/C12/3196; front bonnet on BrakeSaver 3406s).
Kat's equivalents: 30207 (120 V) / 31207 (240 V).
3406 & 3406E (except 1998 models)
Not for the 1998 3406E or 15.8L 600 hp engine — see next table.
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 8600090 | 1,000 W | 120 V | 1" NPT | Immersion | 3600008 |
| 8600120 | 1,000 W | 240 V | 1" NPT | Immersion | 8608377 |
| 8605556 | 1,500 W | 120 V | 1" NPT | Immersion | 3600008 |
| 8600260 | 1,500 W | 240 V | 1" NPT | Immersion | 8608377 |
Without BrakeSaver: replaces the 1" pipe plug in the oil cooler rear bonnet. With BrakeSaver (through 1993): install in the front bonnet.
3406E, 3456, 15.8L 600 hp (1998 models only)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500033 | 1,500 W | 120 V | 1" NPT | Immersion | — |
Installs in the oil cooler rear bonnet. The unique 1998 design is NOT interchangeable with 8605556.
C7 ACERT (2004–2007), 3126/3126B, 3116, 3114, pre-2004 C7
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500015 | 1,000 W | 120 V | 44 mm | Freeze plug | 3600048 |
| 3500016 | 1,000 W | 240 V | 44 mm | Freeze plug | — |
| 3500081 | 1,500 W | 120 V | 44 mm | Freeze plug | 3600048 |
Replaces the core plug at the centre of the right side of the block. Kit includes a high-temperature cordset.
3306, 3304 (with oil cooler)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500043 | 1,000 W | 120 V | 3/4" NPT | Immersion | 3600008 |
| 8600988 | 1,000 W | 240 V | 3/4" NPT | Immersion | 8608377 |
| 8601011 | 1,500 W | 120 V | 3/4" NPT | Immersion | 3600008 |
| 8601054 | 1,500 W | 240 V | 3/4" NPT | Immersion | 8608377 |
Replaces the 3/4" pipe plug at the rear of the oil cooler on the left side of the engine.
3208 (636 CID)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 8602549 | 1,000 W | 120 V | 3/4" NPT | Immersion | 3600008 |
| 8602514 | 1,000 W | 240 V | 3/4" NPT | Immersion | 8608377 |
| 8602611 | 1,500 W | 120 V | 3/4" NPT | Immersion | 3600008 |
| 8602573 | 1,500 W | 240 V | 3/4" NPT | Immersion | 8608377 |
Swivel-style heater replacing the 3/4" pipe plug on the front of the engine. Freeze-plug alternative: 8602816 (600 W, 44 mm, requires two heaters on the 3208).
3176 (10.2L)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 8601267 | 1,500 W | 120 V | 3/4" NPT | Immersion | 3600008 |
Replaces the 3/4" pipe plug on the right rear side of the engine. High-temperature cordset included.
Compare heater and cord buying options
Check the application table for your exact engine. Cords, heater elements and surface pads are separate products.
Part reference
Zerostart 3500111
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3600008
Industrial replacement cord, 15 A, 16/3 HPN, silicone connector K in PTI catalog. Cord only; not a heating element.
Cord / harness only — no heating element.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500077
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500076
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8608377
Legacy fitment associations are not independently verified vehicle-specific purchase recommendations.
Cord / harness only — no heating element.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500075
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500074
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Amazon buying options
Zerostart 8600090
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
Choose your Amazon store
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8600120
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8605556
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8600260
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500013
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500031
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500033
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500015
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3600048
Legacy fitment associations are not independently verified vehicle-specific purchase recommendations.
Cord / harness only — no heating element.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500016
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500081
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 3500043
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8600988
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8601011
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8601054
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8602549
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8602514
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8602611
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8602573
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Part reference
Zerostart 8601267
Catalog starting point: confirm exact engine code, year and installation with the manufacturer.
No exact purchase listing verified yet. These links search Amazon; confirm the part before buying.
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Which port does your CAT use?
The fastest way to identify your heater is the oil cooler plug: on the right side of the engine, at the rear of the cooler, there's a large hex-head pipe plug. 1" NPT means the classic 8600090/8605556 family fits. The ACERT generations moved to O-ring straight-thread ports — 1-5/16" on C11/C13 (2004–06) and 1-3/16" on C9/C15/C16 (2004–06) and everything 2007+. If you're not sure, pull the plug and measure; the thread families are not interchangeable and forcing the wrong one strips the cooler bonnet.
Installation on any of the oil-cooler heaters is the same routine: drain coolant below the port, swap the plug for the element, refill, burp, and only then plug in. The 44 mm freeze-plug heater on C7/3126 engines is the harder job — the core plug has to come out of the block — and many owners have a shop do that one while paying for the part themselves.
FAQ
Where does the block heater go on a CAT C15?
In the oil cooler, right-hand side of the engine. 2007+ C15 ACERT: Zerostart 3500111 (1,500 W) in the 1-3/16" rear port. 2004–2006 ACERT: 3500077. Pre-ACERT C15/C16: the 1" NPT heaters 8600090 (1,000 W) or 8605556 (1,500 W) in the rear bonnet.
What block heater fits a CAT C7 or 3126?
A 44 mm freeze-plug heater in the centre of the right side of the block: Zerostart 3500015 (1,000 W/120 V) or 3500081 (1,500 W/120 V). The kit ships with a high-temperature cordset. The same heater covers the 3126, 3126B, 3116 and 3114.
Are CAT block heaters hard to install?
The highway engines (C10–C16, 3406) are among the easiest heavy-duty installs there are: the heater replaces a threaded plug in the oil cooler, so it's drain-swap-refill with hand tools. The C7/3126 freeze-plug heater is more work because the core plug must be removed from the block.
Compare buying options
Amazon buying options
Kat's 13150 circulating tank heater, 1,500 W
Plumbs into a heater hose and thermosiphons hot coolant through the whole engine — the serious option for big diesels, tractors, and equipment with no frost-plug access.
Confirm the exact specification and application in the listing before ordering.
Choose your Amazon store
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Amazon buying options
NOCO Boost GB150 lithium jump starter, 3000 A
The pro-grade boost pack — rated for gas engines to 9 L and diesels to 7 L. What actually turns over a cold Cummins or DT466 when the batteries give up.
Confirm the exact specification and application in the listing before ordering.
Choose your Amazon store
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Amazon buying options
Howes Diesel Treat anti-gel, 64 oz
The trucker-standard winter conditioner — prevents gelling, adds lubricity, no alcohol. The 64 oz jug treats hundreds of litres; dose every fill from November on.
Confirm the exact specification and application in the listing before ordering.
Choose your Amazon store
Affiliate links. As an Amazon Associate, we earn from qualifying purchases.
Diesel pickups we catalogue fitment for
Part numbers, wattage and cord routing for the light-duty diesels that share a yard with this equipment.
Should you plug in tonight?
Enter your city — we check tonight's forecast and give you a straight answer based on the temperature thresholds that matter.
Keep reading