We flew to Florida from Phoenix to purchase a 2019 Thor Vegas 24.1 last week. Proceeded to drive the rig 2200 miles back home. The first night we overnighted in Lake City Florida at a Super Walmart. Great stay and the rig worked great. A cold front was going through the south and the temp was low enough that we had the rig’s furnace on. If we remember correctly the temps were down in the low 40’s. The furnace kept us toasty through the night. Day 2 we drove on I10 into the middle of Louisiana and overnighted at an RV park. The temps that evening got down into the low 30’s. We woke up to a nice and toasty Motorhome. My wife took a shower that morning and enjoyed a nice and warm shower. The rig uses an in-line water heater to give us hot water. The in-line unit uses propane, on demand, for the water heating duties. After the shower we noticed that that furnace was no longer providing heat to our rig. The furnace sounded like it was trying to ignite the propane to create flame but would immediately stop. Then a few seconds later would try to ignite the flame again but failed. We decided to hit the road and discuss the problem. On the third day we drove to Kerrville Texas and called to see if an RV service shop could look at our furnace. Ronnie Bock’s RV service were very kind to take the time and check out our furnace. Of course it fired right up and worked great for the whole time we were there. (Middle of the afternoon 70 degrees) They suggested that the furnace circuit board had been known to cause problems and they had changed out several of them in the past. We bought a circuit board from them but did not replace it, still trying to determine the cause to the problem. Down the road again. Drove a bit further to Junction Texas and ate some very good BBQ. We got permission from the manager to overnight in their parking lot along with another MH. Went to bed that evening with the rig’s furnace on. The temp that night got down into the high 20’s. My wife woke at around 4am and noted that it was a bit cold in the RV (around 56 degrees). This was quite a bit colder than what we set the thermostat the night before. This time we decided to try a do a bit of troubleshooting. I went outside and verified that the propane bottle valve was indeed all of the way open. Then went inside and turned on the faucet to try for warm water. The indicator in the rig indicates the temp of the water as it warms. It was not getting above 52 degrees and eventually gave an error code of E2. We then attempted to warm water in a pan on the propane stove. The flame came on but was not as intense as it usually is and was struggling to stay on. It appears that we are not providing enough propane for our demands when it gets cold outside. What in the propane line would cause this? I was told by an RV service manager that the propane regulator may be the culprit. Any other ideas???