EasyStart Pro Shows “No Heater”? Here’s What It Means and How to Fix It
Posted by bz@heatso.com on 14th Jul 2025
If you’ve just installed an Espar or Eberspacher heater and are seeing a “No Heater” error on the EasyStart Pro, you’re not alone. Whether you’re troubleshooting an Espar no heater code or unsure how to fix an Eberspacher no heater error, this guide will walk you through the most likely cause and the simplest fix.
EasyStart Pro Shows “No Heater”? Here’s What It Means and How to Fix It
If you’ve just installed an Espar or Eberspacher heater and are seeing a “No Heater” error on the EasyStart Pro, you’re not alone. Whether you’re troubleshooting an Espar no heater code or unsure how to fix an Eberspacher no heater error, this guide will walk you through the most likely cause and the simplest fix.
Here’s how one customer solved the issue in just a few minutes.
Heater Installed, But It Won’t Turn On
A van owner completed their install of an Espar AS3 D2L heater. When they powered up the EasyStart Pro controller, the screen showed “No Heater”, and nothing happened. The system looked fine, but something was off.
What Causes the “No Heater” Message?
Newer Eberspacher heaters include two power connections:
- A thick red wire that powers the heater
- A thin red wire that powers the controller
If the controller wire is connected before the main heater wire, the controller powers up and tries to communicate to the heater - but it can’t find the heater’s ECU, so it shows “No Heater”.
How the Problem Was Fixed
We asked the customer to do the following:
- Remove both fuses
- Reinsert the 20A fuse (thick red wire), wait a few seconds and then insert the 5A fuse (thin red wire)
Once reconnected properly, the controller detected the heater, and everything worked as expected.
Affects More Than Just One Model
This issue isn’t limited to the AS3 D2L. It applies to any second or third generation Espar / Eberspacher heater using the EasyStart Pro, including Airtronic and Hydronic heating systems.
If you’ve installed one of these and see a “No Heater” message, start by checking the wiring sequence.
What If It Worked Before?
If your system was working and suddenly shows “No Heater”, the wiring order is likely not the cause. In that case, check for:
- Weak or unstable power supply
- Loose, corroded, or damaged connectors
- Wiring damage
- A fault in the heater’s ECU
Tip for Installers and DIYers
Always follow the installation manual, and when in doubt, ask. Heatso support is here to help you get it right the first time.
In Summary
If your EasyStart Pro shows “No Heater” error code, double-check your installation sequence. Make sure your heater’s power supply is connected directly to the main battery, then power up the heater first, then the controller. In most cases, that’s all it takes to get your Espar heater up and running.
