Atwood hot water heater -- Too darn hot

dougrainer wrote:

1. I always wonder where people think there is a "code" or "Legal Limit" for things. THERE IS NO LEGAL TEMP LIMIT FOR WATER HEATERS. There is a 125 psi PRESSURE limit in most codes for water heaters.
2. The REASON for 130/140 Auto set Tstats on 12 volt DSI RV water heaters is simple. To get the MAXIMUM amount of hot water(mixing cold with hot) they use the 130/140 auto set Tstats.
3. There are RV water heaters that have a 160 degree tstat and that model has a auto-mixing valve on the exit on the back of the water heater that drops the temp to about 120. BUT, it is adjustable and you can fiddle with the adjustment to get hotter or colder output water.
4. Pilot Controlled RV water heaters do have an adjustable Tstat.
5. The BEST solution for the OP is to buy the aftermarket Adjustable Tstat kit. Doug

https://www.amazon.com/Atwood-93105-Adjustable-Electronic-Thermostat/dp/B001BZ36HM

I tend to shy away from absolutes. There are laws in some states and local areas. For instance the state of washington. According to inspectopedia, a number of states have adopted codes with a 120 degree maximum. I believe some locations, especially other countries, have minimum temperature regulations to prevent bacteria and legionnaire's disease.
I know there will be another set of people who want to argue over whether these apply to RVs. Personally, I don't think most of us are really concerned about "regulations".

I'm also hesitant to make blanket statements about what is "BEST" because everyone's situation is different. BEST for you is what works for you and there are many factors that go into deciding what's best. For many, as some have suggested, "BEST" is to do nothing and mix more cold water with the hot. It's certainly the cheapest and requires no physical changes. But there are obvious drawbacks of potential scalding hazard and not being able to keep regulated temperatures. Obviously, I think the OP was aware that was an option and was looking for a "better" solution for his purposes.

An adjustable thermostat is cheaper than a mixing valve and doesn't require plumbing changes, but it does have potential downsides. The two biggest are less hot water and the risk of bacterial growth with lower temperatures.

Mixing valve with anti-scald isn't cheap, but it's cheaper than a new water heater. It does require plumbing though. More work to install. For my purposes, this is a better solution. The OP will obviously have to decide what the "BEST" solution is for his situation.