Don't worry too much for the criticism. There are many really stupid ideas of how to heat pool water just by searching "redneck pool heater" and the attached picture is a hilarious example. At least you are taking the time to really think this through.
I think everyone is a bit concerned seeing a gas heater mounted directly to the side of a wood deck. As a contingency plan, if the wood deck catches on fire, it will melt the vinyl wall of your pool instantly dumping thousands of gallons of water on your burning deck to extinguish the flames.
I think everyone is a bit concerned seeing a gas heater mounted directly to the side of a wood deck. As a contingency plan, if the wood deck catches on fire, it will melt the vinyl wall of your pool instantly dumping thousands of gallons of water on your burning deck to extinguish the flames.