Turn a burner on the stove on, go up to the propane tanks and turn the valve off, then turn back on s-l-o-w-l-e-y. Just keep trying, mine sometimes takes numerous tries before it lights. I usually wait until I can hear it coming out of the burner on the stove, then I try the fridge next and it does the trick every time.
2008 Chevy Silverado 1500 5.3/ 3.73 Tekonsha Primus brake controller
2011 JayFeather Select 29L
Husky Centerline WDH
w/ active anti-sway