1994 split Lennox heat pump. Reversing valve selinoid is vibrating and was making a lot of noise until I adjusted Metal mounting bracket and tightened. now it is very quite. I did find system with #r22 has below manufacture level for pressures, high suoerheat and compressor could overheat. Estimated just replacing 13lbs factory charge with new environmentally friendly refrigerant could easily be over $1000. Replacing the system would be better idea. Went over tcc plans,
