Thursday, September 22, 2011

95% Goodman GMV furnace won't stay lit, code 3?

brand new goodman gmv furnace 2 stage 80k and 115k was running ok after craigslist install, don't have much money. now though less then a week later it lights up then the flame goes out after 1 to 20 seconds randomly. In trying to figure out what changed I can only say...

1) it rained

2) I closed a vent

3) I messed with thermostat (so stupid!!!)

4) its gotten colder in general

1) I mention rain because I noticed the vent going outside has some water in it looking down it from the outside. it runs through the wall not quite level but with the open end a bit higher so I cannot see how it could avoid recieving some rain water. the installer had the purple glue stuff on the end of it outside like he was going to add a peice to the end maybe to protect it from the rain but I don't know. I did notice when the furnace was running (no flame) water coming out of the chimney thing outside. I should mention there is only one hole in concrete block, they said they were going to try some 'new' venting method thing where they only had to run one pipe. So 2 white pipes come out of the furnace and run to a 'Y' like thing to one pipe going through the wall. I looked down the tube outside and only see one pipe so I'm pretty mystafied about that one.

2) I closed a vent to an unused room. the guy who installed it used 6 inch flex for the vent runs and the furnace was very powerful maybe not enough vents? There are 10 vents all with 6 inch flex duct but 5 are nearly completely closed to force air to the other side of the house. ran ok before though so I don't see how that could be it.

3) I read the white rogers thermostat manual and changed some settings. I think I changed them all back after pulling out the batteries and cutting power to the house but not sure about all settings. I read that some anticipation setting is automatic with digital thermostats so that should be working? The thermo has only 2 wires as wires were not changed during upgrade. ran fine for a week...

4) Its gotten a bit colder out and the duct work the guy did is not too good. the house has a finished and insulated top floor and I'm still using the old, very large, return air duct work. However he put in new, not air tight duct for the hot air. the bottom floor has no rooms or walls or insulation, it is concrete block and thusly cold air from downstairs (where the furnace is) is being sucked into the return air drop he did and especially the filter area which is too big. His duct work also shoots some hot air meant for upstairs out downstairs. when it was around 60 degrees downstairs it ran ok but now that it's colder it's not staying lit. however at the warmest time of day now the temp is the same as when it ran ok and it still will not stay lit so I don't think ductwork or temperature is the prob.

So thats all thats changed since it was working right. I know for sure it was running ok before I messed with the thermostat changing settings but not sure thats when it stopped working.

As to what I see the furnace starts up, flame lights and then after just a few seconds it goes out. If the doors are screwed on, when the flame goes out there is a very signifigant air pressure change inside the furnace as I can see and hear the door bend and a gush of air. with the door off this is not noticable.

Also the red LED flashed 3 times after the flame goes out. It then all restarts light the flame again only to kill it and flash the LED 3 times.

Perhaps most telling (I don't know, guessing here) is the flame itself seems maybe not to be shooting hard enough. It's not all in the duct work area but has come back enough that there is a solid line of flame closest to the front of the viewer. I'm guessing the gas is weak and the flame is being detected where it's not sopposed to be and some heat sensor is shutting it down. I tried adjusting 2 screws and 2 hex things that were all next to each other attached to the gas line but they were all already turned all the way up.

So thats the situation. I kn ow the drain is not clogged, not sure whats going on with the intake but the flame still goes out with the panels off so maybe that answers that. code mentions pressure switch problem but I don't know how to diagnose or fix. everything is brand spanking new though.

If anyone can offer some advise you'll be warming a cold family so thanks a ton in advance...95% Goodman GMV furnace won%26039;t stay lit, code 3?
Sometimes on the Goodmans, when the flame goes out after just a few seconds, it could be the flame rod.

Heres what you do. Pull off the top door, underneathe the burners there is a wire (i think its blue) that goes to a little rod that sticks up into the burners. Take a 1/4 nut driver and remove the screw holding that rod up there.

Take some sand paper, steel wool or maybe even some emery cloth and rub it on the rod, you are basically cleaning it. Make sure you wipe off the rod to ensure there are no particals left on it.

Put the rod back in, tighten the screw, and try to start it and see what happens.

Another thing you might want to check, is make sure there is nothing blocking the exhaust pipe.

Also check the little hoses that go to the pressure switch, pull them off and blow into them, and make sure they are clear of any moisture or debris that may have gotten in there.

Good Luck95% Goodman GMV furnace won%26039;t stay lit, code 3?
look at inside of door code 3 does it say flame sensor? theres a legend inside the door flame sensor take sand paper to little stick in front of one of the burners with it off lightly sand try again
  • ittwit
  • any around women advice
  • No comments:

    Post a Comment