Ruud
Flow / Load Imbalance Under Multi‑Zone Demand
Boiler starts normally but shuts down when multiple zones call for heat
Advertisements
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Advertisements
Possible Causes
Undersized circulator, incorrect zone valve wiring, primary/secondary piping imbalance, low gas input under high load
How to Fix / Troubleshooting
Safety first: Turn off power before adjusting wiring or pumps.
- Observe operation: Note whether the boiler shuts down on high limit or low water pressure when multiple zones open.
- Check circulator sizing: Compare the installed pump to Ruud's recommended flow for the boiler output and system design.
- Verify zone valve wiring: Ensure that the boiler is properly signaled when multiple zones call and that the system pump is energized.
- Consult a hydronic specialist: Complex multi‑zone issues often require redesign of piping or pump selection.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
System Circulator Pump
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements