# Service bulletin IK1900301

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11031193
- Published by NHTSA: 2026\-04\-08
- Manufacturer's number: IK1900301
- Manufacturer's date: 2026\-03\-27
- NHTSA component: ENGINE

## NHTSA's summary

The purpose of this article is to provide the user with the necessary tools and related manuals to maintain, diagnose, and repair an Espar Hydronic S3 Heater \(GEN 3\). The Espar Hydronic S3 \(GEN 3\) Auxiliary Heater is a diesel\-fired coolant heater for maintaining cabin heat without running the engine. The heater uses fuel from the fuel tank to heat coolant before it goes to the heater core in the sleeper HVAC unit. The heater is located under the cab's sleeper area and is powered by the vehicle's batteries.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11031193-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11031193-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Vehicles listed

- 2023 to 2026 INTERNATIONAL LT

JSON: [/v1/bulletins/11031193](/v1/bulletins/11031193)

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