Chiller Water Flow Alarm (E2)Updated 2 hours ago
If your chiller shows E2 or “Water flow malfunction”, it isn’t detecting enough water moving through it. It has shut down to protect the pump. This is the most common alarm, and it’s almost always a quick fix.
Quick checks (in this order)
- Water level. The water must fully cover both hose ports on the tub. Top it up if needed.
- Prime the pump. If the chiller was started before water reached it, there may be air trapped inside. Switch it off, open the filter cup lid and let water fill the cup until it overflows (or pour water in). Then close the lid and power on. Do this every time you refill.
- Filters. A blocked filter is the most common cause. Rinse the mesh and check the cartridge.
- Filter cap O-ring. Check that the rubber O-ring is clean and sitting flat in the filter cap. If it isn’t, air gets in and triggers E2.
- Hoses. Check that there are no kinks, twists or pinches anywhere along the hoses, and that the inlet and outlet aren’t swapped.
- Reset. Switch off at the wall, wait 30 seconds, and power back on.
Did E2 start right after you changed the filter?
Some new cartridges sit tightly in the housing and restrict flow. Run one cycle with the old filter (rinsed), or without the cartridge, with the housing refitted and tightened. If the alarm clears, let us know, and we’ll send replacement filters.
How it works
The chiller needs more than 8 L/min of flow for 40 seconds to confirm a start. It alarms after 5 failed attempts. Its protection threshold is 10 L/min. So even if water is moving, too little of it will still trigger the alarm.
Still showing E2?
- Check the filter housing and the area around the flow meter for debris.
- Disconnect the hoses and check them for blockages inside.
- If you live in a hard water area, check the fittings for scale. See Cleaning & Descaling Your Cold Plunge.
When to contact us
If you’ve checked the water level, primed the pump, cleaned the filters and checked the hoses, and E2 keeps coming back, the flow meter or pump may need attention. Contact us with your order number, model and a short video of the startup.
Prevent it: prime the pump after every refill, rinse the mesh filter weekly, and replace the cartridge on schedule.