9年新的townhouse HVAC坏了，管理公司说修理要5400美元，急求资深地主指点

大家好，我2007年买了个townhouse自住，2013年买了房子，townhouse就交给管理公司租出去了。管理公司发信说房客说空调坏了，不能制热。管理公司找的修空调公司（Quality Care Heating & Air）说冷热不能转换，再加上漏氟利昂，还要换Heater。加起来要5400美元。

修空调公司是这么说的： Returned Friday 12/16 try to get heat working, was able to find zone board it was located in closet on third floor. Bypassed zone board and wired system up on one thermostat, could not get heat to work. checked heatpump located on the ground level, noticed reversing valve would not change over. it would get stuck in cooling mode. I tried everything possible to get this heat to work. The cost to replace reversing valve would be around $2400. Would not fix due to system has a refrigerant laek and we would have to continue to put Freonin in system. I suggest replacing equipment.

Estimate to install new(Airtemp) 5 ton air handler with 10 KW of electric heat, Install new 5 ton (Airtemp) Heatpump. 10 years manufacture parts warranty and 1 year labor warranty.

在线急求资深地主指点，是不是该这么修，这个维修费用是否合理？ 多谢多谢！