Furnace Works Great With Electrical Hookup But

[LilaLS]

We have a TM with a electronic ignition furnace. The
furnace works great with electrical hookup but when we unplug and just go to battery mode (2 new full strength 6 volt batteries) the heater does not seem to want to ignite.

I check all blockage. Everything is clean. The furnace runs great when plugged in and I turn up the thermostat. When I disconnect the 110 hookup and just have batteries then turn up the themostat the igniter just does not ignite the furnace. I know I posted other posts about our furnace but I know now it is not the furnace. Just wondered if anyone ever had furnace ignition problems when in battery mode. I am sure it is some little thing. All other appliances ignite and run just fine in battery mode.

Thanks again for any help!

[BrucePerens]

First, take all metal jewelry off when working on electricity, especially 12 volts. 12 volts won't shock you, but a battery has so much current it can make your ring red hot if you touch the wrong thing, and people lose fingers from hot rings. If a ring won't come off, glove up.

If I'm not mistaken, that furnace only takes 12 volts. So, the problem is with the power quality, not the presence of power. How's your battery? Is it fully charged? If it's AGM you can't do anything for it. If it's a flooded one, is the electrolyte up to the top of the plates? If not, get deionized water and fill it to the line inside of the fill tubes. Watch out, that's a mix of water and acid. Get a voltmeter and measure the voltage under load - that means with lights on and fans running. Then plug the trailer in to AC and measure again. If it's below 12 volts with AC disconnected, your battery may be bad.

[LilaLS]

Thanks for your response. I have two new batteries but will double check the current charge in them. I would hope they charge while they are installed and I am hooked up to the 110 system in the garage. They should be at full strength.