17
ENGLISH
onsenproducts.com
onsenproducts.ca
800-996-5559
ISSUE
POSSIBLE CAUSE
SOLUTION
No hot water flow when
a hot water faucet is
opened.
No/empty fuel source.
Fuel gas valve needs to be open. Refill source tank
(if applicable).
Open the water inlet valve.
Power outage.
Unit requires 120V power to operate.
Flow is too low or becomes too
low (less than 0.66 gpm or
2.5 l/m).
Flow is below the lower limit necessary for stable burner
operation and proper temperature control. Increase the hot
water flow to enable system.
Fuel gas meter special control
restrictions.
Some fuel gas valves may have special control restrictions.
Consult your gas supplier and/or a service professional for
assistance.
Distance from heater to source
is long.
Allow time for hot water to travel through system to reach
the point of use.
Hot water is not the right
temperature (too hot or
too cold).
Temperature set point was reset
due to an extended shutdown of
the unit.
Default settings are restored during extended shutdowns
and custom set points must be re-entered to unit.
Flow is beyond capacity.
Desired water flow is above maximum capacity of unit.
Reduce user flows to re-establish control of temperature
Incoming water is too warm.
If incoming water to unit is very warm and the flow is just
above minimum requirements, the heat generated by the
burner while operating at minimum capacity can make the
water hotter than desired. Increase the hot water user flow
so that the burner system can control the temperature.
Hot water flow produced
is lower than expected.
Water source is restricted.
Check and fully open water inlet valve(s). Check and clean
inlet water screen.
Heat exchanger in unit is scaled.
Clean/descale heat exchanger by flushing per maintenance
procedure.
Incoming water temperature is
colder than expected.
Colder than normal incoming supply water will reduce the
amount of hot water than can be produced. Although the
amount of heat output from the unit is still at full capaci-
ty, you must reduce the user flow and operate within the
capacity range of the heater.
Vent system trouble.
Vent system is restricted in some
manner.
Check air intake and exhaust ducts to ensure they are not
damaged, corroded, blocked, etc.
Water leaking from pres-
sure relief valve outlet.
Water system is operating above
the pressure rating of the pres-
sure valve.
Consult a professional to investigate.
Safety valve is damaged.
Replace safety valve. Consult professional as required.
Blower fan noise can be
heard for some time after
operation stops.
The blower is designed to run for
30 seconds after burner shuts off.
None. Normal operation.