Hot water circulation pump is a centrifugal pump model of a product. Thermal circulation pump temperature within 120 degrees, the installation is divided into vertical and horizontal 2 kinds. Hot water circulation pump failure are mainly no water, lack of flow, noise, vibration, leak several faults, the following specific explanations of various causes of failure and solutions. First, the hot water circulation pump failure Water reasons 1, hot water pump inlet and outlet valves are not open, out of the pipeline obstruction, abortion impeller blockage. Solution, remove obstruction. 2, the motor is running in the wrong direction, the motor phase loss is very slow: adjust the motor direction, sturdy motor wiring. 3, hot water circulation pump suction pipe leaks: tighten the sealing surface, remove the air. 4, the pump is not filled with liquid, the pump cavity air: Open the pump cover or open the exhaust valve, drain the air. 5, inadequate import and export of water supply, suction stroke is too high, the valve leakage: downtime inspection, adjustment (grid water pipe and with the suction process easy to use this phenomenon). 6, pipe resistance is too large, improper selection of centrifugal pumps: reduce pipe corners, re-select the pump. Second, the hot water pump failure flow reasons 1, hot water circulation pump import and export valve is not open, out of the pipeline obstruction, abortion impeller blockage. Solution, remove obstruction. 2, pipes, hot water circulation pump impeller impeller blockage, scale deposition, lack of valve opening: remove the obstruction, readjustment of the valve opening. 3, centrifugal pump voltage is low: voltage regulator. 4, impeller wear: replace the impeller. 5, the use of more than the rated flow: adjust the flow off the small outlet valve. 6, centrifugal pump suction too high: lower suction. 7, pump bearing wear: replace the bearing. Third, the hot water circulation pump fault noise vibration causes 1, unstable pipe support: a solid pipeline. 2, liquid mixed with gas: improve suction pressure exhaust. 3, produce cavitation: reduce the degree of vacuum. 4, bearing damage: replace the bearing. 5, the motor overload heat run: adjust the flow off the small outlet valve. Fourth, the hot water circulation pump fault motor heating reasons 1, hot water circulation pump flow is too large, overload operation: off small outlet valve 2, rub touch: check and rule out. 3, hot water circulation pump motor bearing damage: replace the bearing. 4, lack of voltage: voltage regulator. Fifth, hot water circulation pump failure reasons 1, hot water circulation pump mechanical seal wear: replacement. 2, the pump has sand holes or cracks: welding repair or replacement. 3, the sealing surface is not flat: trimming. 4, loose bolts installation: fastening.