Tractor Block Heaters: John Deere, Kubota, Massey Ferguson & More
A tractor that lives in an open shed still has to start in January — for chores, feeding, or blowing snow — and unlike a truck it rarely gets a warm garage. The good news: nearly every diesel tractor sold in Canada has a factory port or freeze-plug location for a coolant heater, and most installs are simpler than on a car because everything is reachable.
This page covers the common families: John Deere's PowerTech engines and the classic two-cylinder and New Generation tractors, Kubota's compact diesels, Massey Ferguson's Perkins-powered lineup, the International/Case IH farm engines, Yanmar and Zetor compacts, Komatsu equipment, and vintage Ford tractors. Wattages are smaller than highway trucks — 400–1,000 W — because the engines are smaller and the heater usually has all night to work.
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 Numbers are occasionally superseded — confirm against a current catalog or dealer before ordering.
John Deere PowerTech 4045 (4.5L) & 6068 (6.8L)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500020 | 1,000 W | 120 V | 1-5/8" thd | Immersion | 3600008 |
Replaces the 1-5/8" threaded plug on the right side of the engine.
John Deere PowerTech Plus iT4 4045 & 6068 (interim Tier 4)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500069 | 1,000 W | 120 V | 27 mm | Immersion | 3600008 |
Installs in the right rear of the engine.
John Deere — all tractors 1977+ with the large hex plug
Also covers Series 300/400 engines: 4039, 4239, 6059, 6414, 6466, 6076, 6081 and others.
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500029 | 1,000 W | 120 V | 1-5/8" thd | Immersion | 3600008 |
Installs in the large hex plug on the left side of the engine. Point element up.
John Deere Series 300 (3/4-cylinder: 3164, 4039, 4045, 4219, 4239, 4276…)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 8603596 | 1,000 W | 120 V | 3/4" NPT | Immersion | 3600024 |
Replaces the 3/4" pipe plug on the rear face of the engine. 1987+ engines may need a 1" × 3/4" reducer bushing.
John Deere 6105, 6125
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500013 | 1,500 W | 120 V | 1" NPT | Immersion | 3600008 |
Installs in the oil cooler housing.
John Deere 4024/5030 (2.4L & 3.0L, Series 250 PowerTech)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500089 | 600 W | 120 V | 1.25" | Freeze plug | — |
Replaces the 1.25" core hole on the left side of the engine, near the starter.
Kubota M, B & L series (3 & 4 cylinder)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100093 | 400 W | 120 V | 3/4" NPT | Immersion | 3600003 |
M series: install in front. B and L series: right front, with a 1" × 3/4" pipe bushing.
Kubota Super Mini 2 & 3 cyl: Z400, Z482, D600, D640, D662, D722, DG750, DF750, WG600/750; V800 4 cyl.
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100099 | 400 W | 120 V | 30 mm | Freeze plug | 3600004 |
Installs in the back of the head. (Z600/ZH600 use the 3/4" NPT heater 3100093 at the right front instead.)
International / Case IH 966, 1066, 1086, 1466
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100013 | 600 W | 120 V | 1-1/4" | Freeze plug | 3600022 |
| 8608512 | 1,250 W | 120 V | 1-1/4" | Freeze plug | 3600008 |
600 W: installs in the 3rd and 4th freeze plugs on the left side — two heaters required. Alternate: one 1,250 W heater (8608512) on the left side.
Kat's frost-plug equivalent: 30501 (600 W).
International 806, 856, 1206, 1256 & C/D-series engines (gas or diesel)
Covers C152–C301, D166–D407, DT407.
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100061 | 600 W | 120 V | 1-5/8" | Freeze plug | 3600036 |
Installs in the 1st, 2nd or 5th freeze plug on the right side. Point element down.
Kat's equivalent: 11614 (600 W, 1-5/8").
Ford 3000–9000 series tractors (1971 and later)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100112 | 750 W | 120 V | 1-1/2" | Freeze plug | 3600023 |
Installs in the 4th and 5th freeze plugs on the right side — two heaters required, elements pointed down. (1968–70 engines use 600 W 3100065 in the same spots.)
Komatsu equipment: SA6D125; S6D140/SA6D140; S6D170
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 8600880 | 1,500 W | 120 V | 1-3/4" thd | Immersion | 3600008 |
| 8600813 | 1,000 W | 120 V | 1-3/4" thd | Immersion | 3600008 |
| 8602301 | 1,500 W | 120 V | Plate | Immersion | 3600008 |
SA6D125 and 2001+ S6D140: threaded core plug on the right side (8600880/8600813). S6D170 (WA600 loaders): plate heater 8602301 in the 6-bolt water jacket access plate, right rear.
Massey Ferguson MF-35, 50, 150, 235, 2135 & others (Perkins AD3-152 3-cyl.)
Also covers the MF-40, 203, 205 and 2200 with the same engine.
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100013 | 600 W | 120 V | 1-1/4" | Freeze plug | 3600022 |
Installs in the freeze plug on the right side. Point element down. A circulation heater is an acceptable alternative.
Kat's equivalent: 30501 (750 W, 1-1/4") on the right side.
Massey Ferguson MF-65, 165, 255, 302, 304, 365 & 3165 (Perkins AD4-203)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100093 | 400 W | 120 V | 3/4" NPT | Immersion | 3600003 |
Installs in the 3/4" NPT port on the left side.
Kat's equivalent: 11409 (400 W, 3/4" NPT).
Massey Ferguson 88, 333, 444, 555 & 445P
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100054 | 600 W | 120 V | 1-5/8" | Freeze plug | 3600006 |
Installs in the right front freeze plug. A circulation heater is an acceptable alternative.
Kat's equivalent: 11603 (600 W, 1-5/8") at the right front.
Massey Ferguson MF-90, 285, 1080 & 1085 (A4-300)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100093 | 400 W | 120 V | 3/4" NPT | Immersion | 3600003 |
Replaces the existing heater port.
Kat's equivalent: 11409 (400 W, 3/4" NPT) on the right side.
Yanmar compact diesels: 3T72HLE; 4TN82E & 4TNE98
The classic grey-market and compact-tractor Yanmars.
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100003 | 400 W | 120 V | 1" NPT | Immersion | 3600001 |
3T72HLE: left front. 4TN82E/4TNE98: left center.
Kat's equivalent: 11407 (400 W, 1" NPT).
Yanmar 3TN66 & 3TN72 (3-cyl.)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3500001 | 400 W | 120 V | Plate | Immersion | 3600003 |
Bolt-on plate heater at the right rear of the engine.
Kat's equivalent: 11452 (plate style) at the right rear.
Zetor — all models except 278 (4.5L) & 417 (6.8L)
| Part no. | Watts | Volts | Size | Type | Repl. cord |
|---|---|---|---|---|---|
| 3100065 | 600 W | 120 V | 1-3/4" | Freeze plug | 3600006 |
Installs in the left rear freeze plug. Point element up.
Kat's equivalent: 11609 (600 W, 1-3/4") at the left rear, element at 12 o'clock.
Installing a heater in an old tractor
Vintage tractors are the easiest block heater installs on anything with wheels: the freeze plugs are exposed, there's no plastic to remove, and the coolant drains from a petcock you can actually reach. Punch the old plug through its edge with a drift, lever it out, clean the bore with emery cloth, and seat the heater with its O-ring square to the bore. Most 600 W frost-plug heaters need the element oriented a specific way (the tables note up/down) so the element doesn't touch the cylinder wall.
For tractors that pre-date freeze-plug heaters or have inaccessible plugs, two universal fallbacks work on almost anything: a lower-radiator-hose heater spliced into the bottom hose, or a magnetic oil-pan heater stuck to the sump. Both are less efficient than an in-coolant element but need no port at all.
How long to plug in before chores
A 400–600 W element in a compact diesel reaches equilibrium in about three hours; a 1,000 W element in a PowerTech 6068 takes about four. Past that point the heat gained equals heat lost to the wind, so a timer set to switch on at 3 a.m. does everything an all-night plug-in does for a third of the electricity. If the tractor has glow plugs or an intake heater, still use them — the block heater warms the iron, the glow system lights the fire.
FAQ
What size block heater does a tractor need?
Compact diesels (Kubota B/L, sub-30 hp) do fine with 400 W. Utility tractors in the 40–100 hp range want 600–1,000 W. The big John Deere PowerTech engines take 1,000 W factory-style elements. More watts isn't better past these sizes — the extra heat just blows away.
Can I put a block heater in a Kubota?
Yes — nearly every Kubota diesel has a factory location. The B, L and M series take a 400 W 3/4" NPT immersion element (Zerostart 3100093), and the little Super Mini twins and triples take a 30 mm freeze-plug heater (3100099) in the back of the head.
What block heater fits a Massey Ferguson?
It depends on the Perkins engine inside. The AD3-152 three-cylinder tractors (MF-35 through 2135) take a 600 W 1-1/4" freeze-plug heater (Zerostart 3100013); the AD4-203 four-cylinders (MF-65/165/255 family) take the 400 W 3/4" NPT immersion element 3100093. Match the engine, not the badge.
What if my tractor model isn't listed?
Use the universal options: a lower-radiator-hose heater or a magnetic oil-pan heater fit nearly any engine without a dedicated port. A circulating tank heater plumbed into the coolant loop is the high-power option for large or stubborn engines.
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