Raypak FLOW WARNING

What does Raypak FLOW WARNING mean?

Per the XTherm Error Display table, FLOW WARNING means operation conditions do not match the current flow reading. The control has detected an inconsistency between what the unit is doing and the flow it is sensing, which can indicate a marginal flow situation or a flow-sensing discrepancy. It is a warning that prompts checking circulation and the flow-sensing path before it escalates to a hard flow fault.

Symptoms

• FLOW WARNING shown on the controller display
• Operating conditions inconsistent with the sensed flow
• Possible precursor to UNDER FLOW or FLOW ERROR
• Marginal or fluctuating circulation

Common causes

• Marginal water flow near the minimum requirement
• Air in the system affecting the flow reading
• Partially restricted valve or strainer
• Flow sensor or wiring discrepancy

Diagnostic steps

1. 01

   Check circulation

   Verify the pump is running and that water flow through the heater is steady and adequate for the operating point.

2. 02

   Purge air from the system

   Purge any air that could disturb the flow reading or reduce effective circulation.

3. 03

   Inspect valves and strainers

   Confirm isolation valves are fully open and check strainers for partial fouling.

4. 04

   Check the flow-sensing path and wiring

   Inspect the flow-sensing components and their wiring for a discrepancy between actual and reported flow.

5. 05

   Monitor the unit

   Observe operation to ensure the warning clears and does not progress to an under-flow or flow-error condition.

When to call a professional

A flow warning is an early indication of a circulation or sensing inconsistency that can develop into a hard fault and heat-exchanger stress. Pinning down whether the issue is marginal flow, air, a restriction, or a sensing discrepancy typically requires flow measurement and system knowledge. If basic checks of the pump, valves, and air do not clear the warning, have a qualified Raypak service technician evaluate the hydronic system and flow sensing.