I am a sales manager from Wotech heat pump which is a professional manufacturer of multi-functional heat pumps, air source swimming pool heat pumps, domestic/ commercial heat pump water heaters, drying heat pumps, geothermal heat pumps, etc. Our heat pump has been the best choice for a lot of global customers. We have established a profession quality control system and three testing chambers to ensuring offer the perfect product and service to you.Wotech heat pumps have obtained GMC,CCC,CE,CB,ETL certification, during production, we have three leakage checks for each unit. Every component is 100% checked. For more pls visit www.wotech.cn