The domestic hot water system of a five-star hotel has been upgraded to a plate heat exchanger due to the high energy consumption, large water temperature fluctuations, and frequent maintenance of the original volumetric heat exchanger. Our KDP company has decided to use a dual station stainless steel plate heat exchanger (made of 304 material, with a ripple angle of 60 °), matched with EPDM high-temperature resistant rubber pads (resistant to 120 ℃) and an intelligent variable frequency secondary circulation pump set. The system integrates climate compensation function, links solar preheating water tank and gas boiler, achieves stable hot water supply temperature, reduces annual gas consumption, extends the service life of rubber pads, and reduces maintenance frequency to once a year.