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How I Burned, Blew-up and Flooded My Way to a Tankless Water Heater!




This is a story about how not to install a tankless water heater.

After many an RV trip using only the standard 6-gallon water heater, my family and I were fed up with our quick, cold five-minute showers. I felt it was time to upgrade to a tankless system. Being the amazing handyman that I am, I decided to install it myself.

First things first, I removed the stock 6-gallon tank by draining it, disconnecting the electrical and propane (of course with propane shut off), and removing the outer heater door frame so that I could gain access to the mounting screws. Removal was easy. I had this in the bag.

Next, I sized up the new Attwood 90205 On-Demand Hot Water Heater and found that if I removed the outer flaps, I could still use the original door (this may not be recommended, but it worked for me). After that, it was just reconnect the propane, electrical and water lines.

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This all took maybe 45 minutes from start to finish; however, I was not finished. Not by a long shot.

Everything went very wrong when I decided to check the propane connection with a lighter. Yes, fire. I couldn't tell if I smelled gas or not, so I stuck a lighter up to the connection, and a small 1-inch flame appeared. I sauntered back to the propane shutoff, thinking that this was no big deal, but the flame had been directly under the electrical connection and thus melted all of the wires.


Of course, this then required removing the entire system and repairing the damaged wires. Nothing dangerous, but time-consuming.

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Once the wires were fixed, I reinstalled the system and, this time, checked for propane leaks with soapy water. I found no leaks and proceeded to smugly start her up. I cranked up the heat to enjoy my new endless hot water that was brilliantly installed, and of course it worked perfectly ....

Until it started to drip water from an internal connection. So, with a slightly bruised but intact ego, I bled the water out of the tankless water heater and fixed the leak with some Teflon tape. No biggie, really.

At this point I had spent about three-and-a half hours on this installation. I was still somewhat proud of myself, thinking this time it was done. So I turned it back on and went inside the house to get my wife so that I could show off how hot her next RV shower would be.

And then it happened. *BOOM*!!! Steam started pouring out of the water heater door. I rubbed my eyes and checked to see if I still had all of my limbs and appendages. Once I investigated the accident site, I realized that after draining the water from the system, I had forgotten to bleed the air before turning it back on. I then summarized that the 50,000-btu burner boiled off any water left in the system and then popped the pressure relief valve. Or so I thought.

After letting it cool and reassuring my startled family that I was still in one piece, I reset the high-temp kill switch. I then turned on the water pump and tried to bleed the air from the system. But when I went to use the sink, I wasnt getting any water from the hot side. Still clueless to what had really happened, I left the water pump on and went to investigate what was really going on. Ten more minutes went by before I, and my eviscerated ego, found out the true meaning of that big bang. The hot water connection behind the water heater had blown completely apart and the water line was flooding a void between two storage boxes. The underbelly of my rig was a swimming pool, and I began to regret my brilliant idea.


San Fernando Valley springs are not mild by any means, and I spent three hours, in 102-degree weather, on my back removing all of the water out of that space. It took another two hours to replace the broken water line.


In the end, I did it. I am a mechanic by trade and I do not give up. There were quite a few bumps and booms along the way, but I accomplished my goal.

But I have to admit, on our next RV trip, it took two hours to figure out the settings on the water temperature switch. My family had to stand there naked and angry while I investigated. And yes, I may have had to rush out of the RV in nothing but a very small towel to double check the system when I thought I heard a noise, but that's the way it goes. None of us burned our flesh off, and we then took a seven-minute lukewarm shower. Totally worth it.


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