Hey everyone! New pool owner here. Bought a house with an existing 33k gallon in-ground pool with a Pentair Mastertemp 300 which has been working flawlessly for almost two seasons that I've owned it until I decided to clean it and I messed things up royally. 
First off, I was installing a wire mesh to prevent rodents that love to build nests inside. The picture shows one winter of nesting. It was simultaneously disgusting and impressive at the same time. Luckily, nothing seemed to be chewed up and the heater has been working normally. The previous owners told me that they spent like $6k after chipmunks wrecked it a few years back. Anyway, before I installed the meshing I hosed off the exterior and a bit of the interior plastic walls too but it appears I may have gotten water on some internal sensors or something. I just can't leave well enough alone. I should have just put in the mesh and called it a day rather than try to make this thing sparkle like it's brand new again. Mea culpa. There's my OCD in full swing. I'm a doofus. I know. I've been kicking myself for days now. It was a dumb idea to bring the hose anywhere near an exposed pool heater. What was I thinking. (Though the mesh looks professional so I am proud of my handiwork).
When I put everything back together though, the temperature readings were fluctuating wildly, like 96, 106 and 124 when I pressed the heater on button and the heater refused to kick on. It also showed some R=? I don't remember the code and I should have taken a picture but I didn't have my phone on me at the time. I didn't know what else to do so I unscrewed the circuit board from the top to make sure I didn't get any water in that. I didn't. It was bone-dry. However, I scraped one of the lines on the flimsy flexible flat data cable that connects the membrane keypad to the board. After that, the unit was unresponsive. Except...when I pressed this yellow switch on the back of the circuit board it came alive with some number like 264 and then went off. I must have pressed that 3-5 times I wonder what that does? All I knew was that all hope was not lost since it indicated it was sort of still alive.
So I went ahead and replaced the membrane keypad (bought a cheap Chinese brand on Amazon) a few days later it arrived after the heater got a chance to dry off thoroughly in the August heat. Incidentally, I took a leaf blower and hot air gun to the thermistor and other electrical components on the day I hosed it on the intake side of the heater to make sure all the connections were dried out (after reading a ton of posts here about that). Well, after I replaced the membrane keypad everything seemed like it was back to normal. Accurate readings of the pool water temp (70 degrees) which I verified and set point temp at 85. The LED is good, and the heater was kicking on! I thought I was in the clear.
Except I wasn't. The water coming out of the pool jets was barely lukewarm still warmer than the frigid cold pool but not like the spa-like hot water that used to come out before my cleaning fiasco. Oh, and the exhaust air is mad hot! Way waay waaaay hotter than it ever used to be. It almost burned me that's how hot. It seems the heater is burning gas alright but not to heat the pool water instead it's just burning it up into the air for some reason.
My question to you all is, could I have messed up some sensor or something in my hosing down episode that is preventing the heater from heating the water properly and just burning gas up because it has to go somewhere. Or is something else wrong that coincidentally is conspiring to punish me through some sort of pool heater karma?
Note: Please refrain from calling me any names in spite of me deserving it. I feel bad enough and now dealing with a partially working heater. Expensive mistake so take this as a warning to anyone looking to clean the heater prior to rodent-proofing it. Don't use a hose or water! (full disclosure I am an electrical / computer engineer so I am used to breaking/fixing things my whole life - AND YES I SHOULD HAVE KNOWN BETTER!!!) :/ Please help.

First off, I was installing a wire mesh to prevent rodents that love to build nests inside. The picture shows one winter of nesting. It was simultaneously disgusting and impressive at the same time. Luckily, nothing seemed to be chewed up and the heater has been working normally. The previous owners told me that they spent like $6k after chipmunks wrecked it a few years back. Anyway, before I installed the meshing I hosed off the exterior and a bit of the interior plastic walls too but it appears I may have gotten water on some internal sensors or something. I just can't leave well enough alone. I should have just put in the mesh and called it a day rather than try to make this thing sparkle like it's brand new again. Mea culpa. There's my OCD in full swing. I'm a doofus. I know. I've been kicking myself for days now. It was a dumb idea to bring the hose anywhere near an exposed pool heater. What was I thinking. (Though the mesh looks professional so I am proud of my handiwork).
When I put everything back together though, the temperature readings were fluctuating wildly, like 96, 106 and 124 when I pressed the heater on button and the heater refused to kick on. It also showed some R=? I don't remember the code and I should have taken a picture but I didn't have my phone on me at the time. I didn't know what else to do so I unscrewed the circuit board from the top to make sure I didn't get any water in that. I didn't. It was bone-dry. However, I scraped one of the lines on the flimsy flexible flat data cable that connects the membrane keypad to the board. After that, the unit was unresponsive. Except...when I pressed this yellow switch on the back of the circuit board it came alive with some number like 264 and then went off. I must have pressed that 3-5 times I wonder what that does? All I knew was that all hope was not lost since it indicated it was sort of still alive.
So I went ahead and replaced the membrane keypad (bought a cheap Chinese brand on Amazon) a few days later it arrived after the heater got a chance to dry off thoroughly in the August heat. Incidentally, I took a leaf blower and hot air gun to the thermistor and other electrical components on the day I hosed it on the intake side of the heater to make sure all the connections were dried out (after reading a ton of posts here about that). Well, after I replaced the membrane keypad everything seemed like it was back to normal. Accurate readings of the pool water temp (70 degrees) which I verified and set point temp at 85. The LED is good, and the heater was kicking on! I thought I was in the clear.
Except I wasn't. The water coming out of the pool jets was barely lukewarm still warmer than the frigid cold pool but not like the spa-like hot water that used to come out before my cleaning fiasco. Oh, and the exhaust air is mad hot! Way waay waaaay hotter than it ever used to be. It almost burned me that's how hot. It seems the heater is burning gas alright but not to heat the pool water instead it's just burning it up into the air for some reason.
My question to you all is, could I have messed up some sensor or something in my hosing down episode that is preventing the heater from heating the water properly and just burning gas up because it has to go somewhere. Or is something else wrong that coincidentally is conspiring to punish me through some sort of pool heater karma?
Note: Please refrain from calling me any names in spite of me deserving it. I feel bad enough and now dealing with a partially working heater. Expensive mistake so take this as a warning to anyone looking to clean the heater prior to rodent-proofing it. Don't use a hose or water! (full disclosure I am an electrical / computer engineer so I am used to breaking/fixing things my whole life - AND YES I SHOULD HAVE KNOWN BETTER!!!) :/ Please help.