I have an 8yr. old Lennox HP-26-042 heat pump. When I turned it on this week it was not cooling. Checked it out as follows: The two diagnostic LED's are blinking normal. Inside unit is moving air and not freezing up. Claaned condensor coils. At ambient of 85 to 90 degrees F the high pressure is approx. 178psi; suction pressure is low at approx 25psi; temperature of pressure line out of the compressor is approx. 175 degrees F. I added some Freon 22 but pressures did not change. WHAT IS THE PROBLEM? DO I NEED TO ADD MORE FREON? Thanks.