Water temperature fluctuates between hot and cold during a shower.

Safety: Avoid scalding; test water temperature carefully.

• Stabilize flow: Open the hot tap more fully to increase flow through the Alpha heater. Avoid mixing with too much cold at the shower valve.
• Check aerators: Clean faucet aerators and showerheads to ensure steady flow.
• Test for cross-connection: Shut off the cold supply to the heater and open a hot tap. If water still flows strongly, there may be a plumbing cross-connection that must be corrected.
• Inspect flow sensor: Clean or replace the Alpha flow sensor if it is sticking (see E12).

If fluctuations persist, have a technician verify sizing and control operation.