Having an issue with my furnace

[DrSoos21]

My furnace seems to work only when it wants to. When I try to turn on ,it clicks normally ,however the furnace only randomly starts. It's not the fan itself. That seems to work just fine. when i turn the thermostat up that it has a mind of its own.

 

[tlmgcamp]

Your first sentence opens the opportunity a lot of comments that may be humorous but not helpful. That said, I suggest that we can use more specifics. Having a mind of its own doesn't provide a full picture of what is happening

 

[1stimerver]

We had a similar problem and it turned out to be stink bugs in the burner tube...
That's the first thing I would look for.

Safe travels and all the best.

 

[DrSoos21]

Your first sentence opens the opportunity a lot of comments that may be humorous but not helpful. That said, I suggest that we can use more specifics. Having a mind of its own doesn't provide a full picture of what is happening

I was trying to be noticable. thanks for response. Propane supply is not issue. I do get a random E 1 error message on thermostat ,that I'm not sure if related. As I said it is a random thing. Sometimes system works fine, then sometime when i try to fire up Furnace normal click acknowledging temperature change but fan and furnace do not start. Sometimes if I turn to off position then turn just fan on, then quickly go to heat it works. Not consistent though. Fuse is good,all breakers seem to be working fine. AC works fine.

 

[DrSoos21]

We had a similar problem and it turned out to be stink bugs in the burner tube...
That's the first thing I would look for.

Safe travels and all the best.

Good suggestion ,thanks ,I'll check that.

 

[Henry J Fate]

The picture of the thermostat shows a set temperature of about 63F and in heat mode.

Have you tried raising the set temperature higher to 75F-80F ?

It could be a bad thermostat. The mode switch could be intermittent or possibly the set temp switch.

Make sure all the wires and connections are good.

Also.....The fan speed selection switch probably will not effect the fan in heat mode and will not matter what fan setting is being used. The fan is controlled by the heater control board and has timed sequences for turning on before ignition and shutting down after the flame goes out.

Do you have good 12 volt power ? Either a converter/inverter charger and batteries ?

Not sure what the E1 code means.

 

[Henry J Fate]

E 1 code appears to be a communication problem from thermostat to heater. Could be a bad cable or wiring. Maybe low 12 volt voltage.

The furnace runs on 12 volt power.

 

[gwinger]

Where are you seeing the E1 code on an analog thermostat?
Even though the fan runs, doesn't mean the fan is at full speed.

 

[Mark_K5LXP]

My money would be on the fan high/low is only for A/C. Generally furnaces do not have an independent on/off and speed control like the A/C does. I wonder if that thermostat is even electronic or just a mercury bulb or bimetallic switch in there. Curious too where the E1 error was being displayed. Make/model of the heater will indicate what it's power and control requirements are and drive subsequent testing.

Mark B.
Albuquerque, NM

 

[Henry J Fate]

If it is a propane furnace, most likely the fan option switch is not in the heater control board circuit at all. Fan control is dedicated to the heater control board. It simply runs, or not runs, from the thermostat set point on/off switch.

I am fairly certain that the thermostat is electronic but I do not know where the E 1 error code was displayed.

 

[Kirk]

I do get a random E 1 error message on thermostat ,that I'm not sure if related.

Where do you get the E1 error message? The thermostat in your picture doesn't appear to have any place to display an error code. The thermostat that you show also controls the air conditioner and so the thermostat sends it's signals to a control circuit board that is in the bottom of your air conditioner and that circuit board then chooses to sent that signal to the air conditioner or the furnace, depending upon the left switch. It is selected to the heat position as it should be. If the furnace blower starts each time you increase the thermostat set point, then it is getting the appropriate signal. You have not said what furnace you have but all of them work pretty much the same way. The blower starts first, then after a short delay, the propane valve opens and the spark is triggered to ignite the propane and heat then begins. If that blower does not move enough air for safe operation, there is a sensor called a sail switch that will not close and so it will never open the propane valve or trigger any spark. Based on the picture of your RV I am guessing that it must be about 20 years old so the furnace blower probably just runs until you turn it off when the gas fails to ignite. There are several other things that could cause the symptom if you are getting the blower and nothing more when things fail.

 

[gwinger]

It could also be a problem with air flow. Make sure none of the ducts are blocked and the burner intake and exhaust are clear. Insects love to build nests in the burner tubes.