Raypak FLOW WARNING Error Code
Operating conditions do not match the current flow reading.
Source: hvac/raypak/47951c62__h-1005a__ryp-xtherm-1005a-2005a-iom.pdf
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
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Diagnostic steps
Check circulation
Verify the pump is running and that water flow through the heater is steady and adequate for the operating point.
Purge air from the system
Purge any air that could disturb the flow reading or reduce effective circulation.
Inspect valves and strainers
Confirm isolation valves are fully open and check strainers for partial fouling.
Check the flow-sensing path and wiring
Inspect the flow-sensing components and their wiring for a discrepancy between actual and reported flow.
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.
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Other Raypak Error Codes
Outlet water sensor fault on the XTherm/MVB controller display.
High limit sensor fault on the XTherm/MVB controller display.
Inlet water sensor fault on the XTherm/MVB controller display.
Gas pressure / PIM wiring related error on the XTherm/MVB controller display.
Ignition fault on the XTherm/MVB controller; clear with RESET.
Heater temperature tripped the high limit on the XTherm/MVB controller.
False flame detected on the XTherm/MVB controller display.
Identity card fault on the XTherm/MVB controller; check ID card and wiring.
Internal control fault on the XTherm/MVB controller; reset power, replace control.
Temperature difference between inlet and outlet exceeded the setpoint.
Low 24 VAC power; check power supply wiring and transformer.
Blower speed out of range; check blower wiring and blower.