A #1 Best Heating Cooling Appliance Drain Opening

Furnace only worked intermittently. Called repairman and he responded promptly. Checked furnace, said he thought water had backed up in PVC pipe so he cut it off and installed a cap for draining. A fair amount of water was drained. Furnace worked for a short time when he left. Came back, replaced membrane, said part cost $88 but I found identical part on web for $12. Furnace worked for a short time when he left. Came back a third time, installed a brass fitting in a different PVC pipe to provide air-tight suction. Checked electric connection on gas valve and discovered wire was loose, tightened fit. Said he hoped gas valve did not need to be replaced because part would be very expensive. Started and stopped furnace four times and it worked each time. Worked again for a short time after he left. First visit was $108.00. Second visit was $131.00. Third visit was $142.00 for a total of $371.00, after which the furnace still did not work. I called another repairman the next day who installed a new gas valve for $146.00 parts and labor and furnace is working perfectly now.