State Temperature Fluctuation / Cold Water Sandwich

State tankless water heater: hot water temperature fluctuates between hot and cold during a shower.

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.

Possible Causes

Minimum flow not maintained, Partially clogged inlet filter, Faulty flow sensor, Inconsistent gas supply pressure

Safety: Water temperature swings can cause scalding. Warn users until resolved.

Clean inlet filter: Shut off water, remove, and clean the cold inlet filter screen.
Check flow rate: Ensure fixtures provide at least the minimum flow required by the State tankless model. Avoid low-flow showerheads below spec.
Inspect flow sensor: Clean or replace the flow sensor if it sticks or reads erratically.
Gas supply: Have a technician verify gas pressure remains within spec during operation.

Medium 3/5

Flow Sensor Assembly

Check Price on Amazon

We may earn a commission from links on this page.