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Generic tankless · Water heater

No hot water, no code shown No power or gas supply reaching the unit

DIY-friendly

What this code means

If the display itself is blank, the fault is upstream of the unit's electronics entirely.

Most likely causes

What to try first

Confirm the breaker hasn't tripped and that any gas shutoff valves along the line are in the open position.

Good news: this one is often fixable without a service call. If it persists after the steps above, have it looked at.

FAQ

What does Generic tankless error code No hot water, no code shown mean?

No power or gas supply reaching the unit. If the display itself is blank, the fault is upstream of the unit's electronics entirely.

Can I fix Generic tankless code No hot water, no code shown myself?

Often, yes. Confirm the breaker hasn't tripped and that any gas shutoff valves along the line are in the open position.

What causes Generic tankless code No hot water, no code shown?

The most common causes are: tripped breaker or unplugged power cord; gas supply shut off at the meter or an inline valve; blown fuse in the unit's control box.

Other water heater brands: Rheem · Ruud · Rinnai · Navien · Noritz · Takagi · A.O. Smith · Bradford White · State / American · Generic electric

This information may contain errors or not apply to your exact model — always double-check it against your appliance's own manual before acting. If there's any chance of a gas, fire, electrical, carbon monoxide, or other safety hazard, stop and call a licensed professional or the appropriate agency (e.g. your gas utility) instead of relying on this page alone.