Randell CHt

What does Randell CHt mean?

On a Randell prep table with the Carel controller, CHt is the dirty-condenser alarm. It warns that the condenser coil is dirty or that condenser airflow and heat transfer have dropped, which the controller detects as a high-side condition. A blocked condenser reduces cooling capacity and, if ignored, can eventually damage the compressor.

Symptoms

• Display shows CHt with the alarm LED lit
• Visible dust, lint, or debris on the condenser coil
• Cabinet has trouble holding its set point
• Compressor runs longer and the machine compartment runs hot

Common causes

• Dirty or clogged condenser coil restricting airflow
• Objects obstructing airflow to or from the machine compartment
• Condenser fan not moving enough air
• Insufficient clearance or surrounding heat sources

Diagnostic steps

1. 01

   Confirm the alarm

   Verify the Carel display reads CHt with the alarm LED lit, identifying the dirty-condenser condition.

2. 02

   Disconnect power before cleaning

   Ensure the unit is disconnected from power before working in the machine compartment, per the manual.

3. 03

   Clean the condenser coil

   Clean the condenser coil monthly with coil cleaner and/or a vacuum and brush, brushing in the direction of the fins so airflow and heat transfer are restored.

4. 04

   Clear any obstructions

   Remove objects blocking airflow and confirm the unit has adequate ventilation around the machine compartment.

5. 05

   Contact service if it persists

   If CHt remains after cleaning, the condenser fan or refrigeration system may need attention; call service at 888-994-7636.

When to call a professional

Cleaning the condenser coil is part of routine owner maintenance, and the manual warns neglecting it can void warranty and destroy the compressor. Call a Randell Authorized Service Agent when CHt persists after cleaning, when the condenser fan is not running, or when a refrigeration fault is suspected. Service on these R290 units must be factory-authorized; reach service at 888-994-7636.