Customer called us out due to no heat. When speaking to customer he stated that he replaced inducer and pressure switch by ordering them online. During inspection found weird noise coming from inducer. When inducer was running it was whistling. Removed inducer and found no gasket installed with new inducer. Checked pressure being pulled by inducer and got 1.65. Pressure switch requires 1.74. After removing and adding gasket from older inducer and putting back on run system and pull 2.11 inches of water column. System started to run and heat after about 10 minutes of running gas valve failed. While inspecting unit found inducer and blower are over amping. Blower also has build up on it. This build up can cause system to lose up to or more than 35% of its efficiency. Recommended cleaning blower, replacing gas valve and inducer motor. Customer declined all recommendations. Customer only wanted to go pick up his own part and replace it himself.