New Cruiser MPG 2400BH battery draw issues...

So we recently purchased a new 2016 Cruiser MPG 2400BH trailer...... And the fun begins, first day home and the batteries are so low that the awning will barely move. Figuring that the dealership forgot to charge the new dual 6v 210ah Interstate batteries I plug it in. after a few days I check the trailer and everything seems ok. later that week I install a 260 watt solar system with a remote display, transfer switch and 1500 watt inverter. Now things all seem good as the batteries have been charging all week and both the inverter and solar displays read fully charged. A week later we load the trailer and head out on our first 6 day trip in the new unit.
I should mention that this is our third trailer running a dual 6v battery setups. The solar and inverter setup were transferred from our previous rv and had no issues keeping our batteries topped up during days off grid camping with the family charging every conceivable electronic device.
First day in camp all seems good until we are wakened by the low voltage alarm going off on the co detector and inverter. Day two consisted of running the generator a total of 6hrs and full sun hitting the panels peaking at about 14.5 amps peak. Evening hits and we are not fully charged but above 90 percent which I figure will be more that ample power...... Nope wrong again... roughly 4am and low voltage alarms going off again, and so on for the rest of the trip.
We pretty much tried every form of power saving that we could think of with no positive results...
As soon as we arrived home the batteries were removed and taken in for testing... Next day I returned to the dealership and they replaced the batteries with two new 225ah batteries. Figuring the problem was solved I installed the batteries, made sure they were fully charged and headed out the next week for another week of camping.. While marginally better we found we still couldn't make it through a night without the batteries dropping to 12-12.2 volts by morning, without the furnace running... Running the furnace minimally would only insure the alarms would go off between 3 and 4 am...
Week number 2 I am now angry, and I have another three day trip planned and no time to look for problems.. Yup those three days all with low batteries in the am. I could not run the furnace at all during the night without the batteries being completely depleted even with solar and as much generator time as I could get during the day...
So now I am home and the trailer is going to go back to the dealership for testing and repairs. But not before a little investigative work of my own.
What I did find out so far is that the difference in power between the charge controller and batteries is roughly .8vdc when charging.
When the furnace is being run or the slide or awning are being operated the voltage reading on my charge controller drops to 11.8 -11.9 volts even when the batteries are near fully charged.
Any use of the furnace basically sets off the low voltage alarm on the CO detector if the batteries are anything under 90% charge.
I have also found that there is a condensation heat strip on my fridge that can't be turned off that is always drawing power... What a stupid frickin idea that is..
I am also assuming that the wiring is not adequate to run the trailer without running into a low voltage situation whenever running higher draw items...

Anyway, this is getting long winded so I will stop for now.
I am going to pick up a proper multi meter for measuring draw sometime this week and will post my results.

Any other ideas or suggestions of things to check would be greatly appreciated..

Thanks