Hi, Hope you can help me to look at the right direction... Have Goodman furnace for 5 years, it's GMVM96, was running no problem all the time. Recently it started failing to start up heat. When it happens I find the furnace with solid "H" in the diagnostic window and no flames. Usually restart would solve the problem but it started getting worse: Lately when I restart the furnace with the switch, it attempts to start, the fan is on, ignitor starts, flames are on and visible, and then fan is slowing down and eventually the flames are shutting down. Furnace makes 3 attempts and then shuts down with the E0 code. I used Fault Recall button to clear up the history and after that the furnace started as normal. This happened more than twice now so there must be definitely a problem. What I am not getting is that if that would be a physical problem with something, the furnace would not start at all, but it is intermittent so I don't know where to start. I checked and cleaned the flame sensor, changed the filter and thermostat batteries, checked pipes. Please help. Thank you

I have a Goodman GKS90703BXAD, i got the same 4 blinks. We called a contractor to look at it. They want $549 to replace the high limit switch and more than $3,000 to replace ignitor, flame sensor, and some pressure switch. I thought it was very expensive. I Google around and found this site and do some troubleshooting myself. I bought the High Limit switch and other maintenance items Ignitor and Flame sensor. The total parts cost me $40 and replace the parts in 15mins. However, the fire still did not start. I started checking the main control board and saw the 2A switch. I pulled it out and inspected and it was not broken. I noticed there were dust particles around the fuse socket. I dust it off, plugged it back in, and the Flame started and no more 4 blinks. I took out the old High Limit Switch and checked for continuity. It was good. The technician was wrong to begin with, he was just based on the diagnostic light to give us the proposal. I was glad I did a second look. This lesson taught me Never trust a technician on the 1st one you call and never go with the 1st proposal Do some home work yourself before calling the technician I bought all the parts from the web site [URL="http://goodmanparts.net/"]BUY GOODMAN REPLACEMENT PARTS[/URL] or SuppliesDepot [URL]https://www.suppliesdepot.com[/URL] Very helpful, honest, right on the spot with the parts I need. hc [COLOR=#008080]Separated from...[/COLOR] [url]http://www.doityourself.com/forum/gas-oil-home-heating-furnaces/459875-goodman-gas-furnace-high-limit-switch.html[/url]