A.O. Smith CAHP-120C Series, Руководство пользователя

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7 Trouble Shooting Instructions
7.1 General
Perform the following inspections, try to find the reasons of the faults and correct them
before asking the service for the water heater.
Perform as this check list before asking for service for the water heater, the hot water
supply would probably be recovered quickly and it may be unnecessary to call for service.
Please disconnect the power supply before checking the water heater.
7.2 No hot water or insufficient hot water
1. Check whether there is a trip on the air break.
2. If the water has been superheated and is cold now, the high temperature limit may trip.
Open the top service panel and the door of upper element and then press the “reset” button. If
the high temperature limit trips repeatedly, ask the supplier to check it.
3. The hot water has a higher demand and it may beyond the hot water supply capability of
the heater.
4. If the water inlet temperature is lower, it may need longer time to heat the water to the
setting temperature.
5. Check the water heater or the hot water outlet tube for the leakage.
6. The precipitation and the scale in the tubes can affect the operation of the water heater.
More details refer to “Maintenance Instructions”.
7.3 Noise from the water heater
1. When there is precipitation or lime scale on the surface of the heating elements, a hissing
sound would occur during the operation of the water heater. The noise is normal, but the
scale on the bottom of the tank or on the surface of the heating elements should be cleaned.
More details refer to “Maintenance Instructions” instruction.
2. It is normal that noise will occur from some electrical components of the water heater.
When the heating elements start or stop operation, a click will be heard from the contactor. A
drone sound will occur from the transformer or the relay on the control board.
3. It is normal that noise will occur from the heat pump system. A whir sound will be heard
when the fan motor operates. Noise will occur from the compressor. When the compressor
starts or stops the operation, a sound will occur and it is from the refrigerant flow inside tubes
of heat pump.
7.4 Water leakage
1. Check the drain valve of the water heater for closing completely.
2. If the T&P relief valve outlet has leakage, it can be that:
a) The water temperature is too high.
b) The T&P relief valve is damaged.
c) The water pressure is too high.
3. Too high water pressure is the most common reason of the leakage of T&P relief valve. It is
usually caused by “closed system”. The check valve in the water inlet tube cannot balance
the expanded hot water pressure and the pressure inside the main tube. The water must be