InSinkErator distinguishes brief installation or startup dripping and sputtering from continuing symptoms in its tank-and-faucet hot dispensers. Identify the exact tank, faucet and operating history before changing anything. A high setting can cause boiling and spitting, but it is not the only possibility. Follow matching instructions, keep clear of hot discharge and obtain help for persistent leaks or unsafe conditions.
Identify the heated tank and its dedicated faucet
This answer covers InSinkErator instant hot-water dispensers with a tank and faucet, not a whole-house recirculation pump. Record both model numbers and find their matching installation and safety instructions. Do not assume the small appliance follows the ordinary sink faucet's cartridge or shutoff procedure.
Note whether it was recently installed, moved or serviced. Record whether dripping is brief and intermittent, continuous, or accompanied by forceful hot water or steam. Observe from a safe distance and keep hands and children away from the discharge.
Startup and continuing symptoms are different
InSinkErator's dripping support guide describes brief initial-installation dripping. Its spitting support guide likewise describes sputtering during initial startup. Those statements do not establish that every continuing drip or steam discharge is harmless.
The manufacturer lists excessive tank temperature as one possible cause of boiling and spitting. Other items in its guides include incoming-tube restrictions, extended tubing, water-supply conditions and faucet problems. A symptom alone cannot select among them. Record the history for support instead of repeatedly changing parts or waiting indefinitely for a persistent problem to disappear.
Use the correct controls and startup sequence
The dripping guide distinguishes a thermostat dial from the HWT300 touchpad. Follow the exact tank's instructions for any owner adjustment; do not copy another model's button sequence or a universal temperature setting.
The installation guide directs filling the tank before it is plugged in. Its complete directions govern a new or reinstalled unit, including the required connections and flushing. A power light does not establish that commissioning was completed. Have the installer or manufacturer review uncertain startup history rather than energizing an empty tank to test it.
Supply-pressure requirements, approved filtration and tube routing also depend on the actual arrangement. Do not bypass an RO system, extend tubes or alter supply pressure merely because a generic support article mentions that possibility.
Separate a cabinet leak from spout behavior
Water under the sink needs its own safe response. Sink leak locations help identify where water appears, but hot-appliance plumbing and electrical parts require their own instructions. If electrical equipment or its surroundings are wet, do not touch the plug or reach through water; arrange safe isolation and qualified assistance.
Do not disconnect a hot or pressurized fitting, spray cleaner into the controls or open the powered tank. For continuing spitting, unresolved dripping or a visible appliance leak, stop using the dispenser and contact manufacturer support or the appropriate qualified provider.
Fixture shutoffs address the water supply. Faster hot water throughout the house is a different piping question and does not repair this dispenser.