dickandlois Report post Posted June 16, 2015 Recently needed to find a hotshot control/thermostat for an Atwood water heater and the OEM part is no longer available. The part number was 91853. This is the replacement I found: Vangard #15A524 or Robert Shaw # 5600311. In some regards they are better specification wise. The OEM part was set up for just 120 volts AC and the replacement is a direct footprint match that is used on residential electric water heaters is set up for 220 volts. This allows it to be used with the 2 heating elements found in residential style water heaters. RV water heaters are not set up with 2 heating elements that are required for fast recovery. When using this unit one only uses one side on the control to maintain the preset temperature(between 125 and 130degs). Tested the unit over a 2 week period and it maintained a water temperature of 132degs. when drawing a limited amount of water, the temp will drop as hot water is used. So if one is taking a shower or washing dishes the LP portion of the system will need to be enabled to maintain the required recovery rate. Not all water heaters us the same system control boards. There are models that use modules that control both the Electric and LP for the water heaters. As always, if you are not up to speed when working with electrical wiring; get help !!!! Rich. Share this post Link to post Share on other sites
jleamont Report post Posted June 16, 2015 Good info Rich. So what did you do? Here's my story around hot water heaters in RV's Our last coach had a 6 gallon Atwood gas only hot water heater. I removed it and tossed into the trash, honestly the DW told me if she ever takes a cold shower (and she likes to shower long) the coach will GO AWAY. So after testing it a few times and only having hot water for a few minutes I decided to pull the unit and replace it with a tankless, best idea I ever had (i got to keep that coach for 6 years. The unit required no regular maintenance and was very efficient on propane. Now with latest coach it has the Hydronic system we still have the ability to take long showers, but she picked this coach so if it could not not keep up with her showers I would hang my hat on that....I am still sure I would loose. Share this post Link to post Share on other sites
