ShaggyRV Posted October 15, 2013 Share Posted October 15, 2013 OK. So my furnace lights no problem. A new issue has popped up. When it gets to the set temp inside the thermostat clicks. this used to cause the flame to shut off then the fan would run to purge out any unburned gas. then after a few seconds the fan would shut off. Well now the flame stays burning and when the fan stops the flame keeps going then slowly goes away. Its like the gas valve is not shutting properly. The flame eventually goes out but it takes a bit. What made me see this was happening was that last night I was using the furnace for a little while in the driveway. Shut off thermostat and left. Today I go to the RV and smell gas. I turn off the gas for awhile and let it air out. I then turned and the gas and lit the furnace. This is when I noticed the abnormal behavior. After it shut off I started smelling gas again. I'm thinking gas valve or main board. Can I test the valve? Quote Link to comment Share on other sites More sharing options...
fred heath Posted October 15, 2013 Share Posted October 15, 2013 I wouldn't light the furnace again until you find the gas leak. An old trick I've used in the past is to buy a bottle of kids bubble soap and put it into a small spray bottle. Spray all your gas connections and look for leaks. You should see bubbles where the leak(s) are. Is your lp tank almost empty? It could be a pressure issue. It also works well for tires. Quote Link to comment Share on other sites More sharing options...
ShaggyRV Posted October 15, 2013 Author Share Posted October 15, 2013 I think the leak is the gas valve not properly shutting in the furnace. I thought I made that clear in my post. Anyhow I have seen many start up problems with these furnaces. mine seems to be the first shut down process problem. Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 15, 2013 Share Posted October 15, 2013 They are supposed to do a pre and post purge of the fire box it could be possible that the controller is holding the gas valve on also. That is not a good thing I would leave that one to a certified tech. Quote Link to comment Share on other sites More sharing options...
ShaggyRV Posted October 15, 2013 Author Share Posted October 15, 2013 Well thank you so far to all who have replied. I'm going in with my multimeter to start checking things out. I'll let you guys know what I find. BTW I have been working on electronics for over 35 years. I just wanted to see if anybody had some past experience with this issue. I can figure it out though. Wish me luck! Quote Link to comment Share on other sites More sharing options...
WME Posted October 15, 2013 Share Posted October 15, 2013 Check the shut off valve, does it use voltage to open AND close it? Or is it Voltage open spring close? See if it comes apart and price a new one. Decide piece of mind or $$$ Quote Link to comment Share on other sites More sharing options...
Derek up North Posted October 15, 2013 Share Posted October 15, 2013 Hopefully the design is "Fail Safe". Quote Link to comment Share on other sites More sharing options...
Maineah Posted October 15, 2013 Share Posted October 15, 2013 It is a dual valve fairly complex. If it's powered with the fan off the control board is toes up. Dumb question how is the gas stove? Blow torch or normal? Quote Link to comment Share on other sites More sharing options...
ShaggyRV Posted October 16, 2013 Author Share Posted October 16, 2013 The stove, oven and fridge are fine. I don't use the hot water heater as it was bypassed when I bought the rig. I verified the furnace doing the same thing today. Verified the gas is leaking from the furnace. Found a melted wire. something shorted in there. Anyhow I turned off the valve for the furnace and no more leak. Further troubleshooting to follow when I get the time. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.