The Wacker Neuson Thermostat is a genuine OEM Thermostat designed for the APT4S and APT4T pump series, including standard, surge brake, electric brake, and cold weather configurations. As a factory-authorized component, this part meets the exact specifications set for these machines, ensuring it integrates correctly without any guesswork on fitment. Verified against the APT4S Pump with Skid, APT4T Pump with Surge Brake, APT4T Pump with Electric Brake, and their respective cold weather variants, the is the correct replacement when the original thermostat requires service.
Key Features
- OEM-Calibrated Temperature Regulation — Manufactured to the exact opening temperature and flow spec of the original, so coolant circulation switches at precisely the right point in the heat cycle.
- Drop-In Housing Fit — Matches the original thermostat housing dimensions and sealing surface on APT4S and APT4T engines, seating correctly without rework or adapter fittings.
- Broad APT Series Coverage — A single part number covers the full APT4S and APT4T lineup, including surge brake, electric brake, and cold weather variants.
- Protects Engine from Thermal Stress — A correctly functioning thermostat keeps the engine in its optimal operating temperature window; a failed unit risks chronic overheating or overcooling, both of which accelerate wear on pump components.
- Genuine Wacker Neuson Part — Sourced directly through the Wacker Neuson OEM supply chain, carrying the same part number — 5200020115 — as the component originally installed at the factory.
A thermostat controls the flow of coolant between the engine and the radiator by opening and closing in response to coolant temperature. When the engine is cold, the thermostat stays closed, allowing the engine to reach operating temperature quickly and efficiently. Once the target temperature is reached, it opens to let coolant circulate through the cooling system and shed heat. A worn or stuck thermostat — whether stuck open or stuck closed — disrupts this cycle, leading to either persistent overheating or an engine that never warms up properly, both of which affect fuel efficiency, output performance, and long-term engine health.
Part Details
| Part Number | 5200020115 |
|---|---|
| Brand | Wacker Neuson |
| Part Type | Genuine OEM |
| Description | Thermostat |
Compatibility & Fitment
| Name | Model | Machine Number |
|---|---|---|
| APT4S Pump w/Skid | APT4S | 5200018977 |
| APT4T Pump, Surge Brake | APT4T | 5200019643, 5200019644 |
| APT4T Pump, Surge Brake, Cold Weather | APT4T CW | 5200019792, 5200019793 |
| APT4S Pump w/Skid, Cold Weather | APT4S CW | 5200019798 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
