From: wolverine01@charter.net   
      
   On 11/19/2024 11:53 AM, Ted Heise wrote:   
   > On Tue, 19 Nov 2024 11:48:15 -0600,   
   >    sticks  wrote:   
   >>   On 11/19/2024 9:19 AM, Ted Heise wrote:   
   >   
   >>> I may have alluded to this before, but last time we camped on   
   >>> a flatspot in our Lance 1475 the night temps dropped into the   
   >>> 40s or 50s and I had trouble running the furnace on 12 V.   
   >>> It's a Truma Combi Eco Plus; the gas would fire up and the fan   
   >>> would run for a minute or two, then stop--without having   
   >>> brought the inside temp up to the thermostat setting.   
   >>>   
   >>> You may recall that this unit was replaced under warranty   
   >>> earlier this year (due to E6H error codes suggesting   
   >>> combustion air motor problems).  But this more recent behavior   
   >>> doesn't seem connected.   
   >>>   
   >>> As near as I can tell, the unit should run on propane with 12   
   >>> V power for the fan.  The battery was at full 100 Ah capacity,   
   >>> so it wasn't a low charge state.  I'm wondering if being LI is   
   >>> a factor, for example is it possible there is internal   
   >>> resistance in the battery that limits the current?  Seems   
   >>> crazy, but I'm not sure what else to think.  FWIW, it's a Li   
   >>> Time battery (from China), and has worked as expected or even   
   >>> better.   
   >   
   >>   If the furnace actually operates as it should when it is   
   >>   running, I would first think about the thermostat.  For   
   >>   example, I would try and raise it higher to see if it runs   
   >>   longer and then shuts off still without reaching desired   
   >>   temperature.  If it still does this, I would be interested in   
   >>   finding out where the probe for temperature sensing is located.   
   >>   It might just be too far away from the thermostat, and too   
   >>   close to the hot air vents.  This unit has a setting for   
   >>   temperature offset for RV's where this is an issue.  If the   
   >>   furnace shuts off 5 degrees before desired temp, you adjust the   
   >>   offset by this amount.   
   >   
   > Thanks for the thoughts, but I'm a bit skeptical of that   
   > possibility because it ran fine once I fired up the generator.   
   > My bad for not mentioning that bit.   
   >   
      
   The unit shuts off when voltage gets below 11 volts.  I know it's   
   supposed to be a good battery, but the only way to know for sure what's   
   going on I think would be to put a voltage tester on the battery when   
   the heater is on and see how low it goes when the fan kicks in.   
      
   110 AC is definitely preferable for the unit, but it should go at least   
   one night I would think an the battery and you'd charge it up the next day.   
      
      
   --   
   I Stand With Israel!   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)