Troubleshooting Dometic RV Water Heater Producing Water That Is To Hot

Updated 08/15/2025 | Published 08/10/2025

Question:

Installed new domestic hw heater 6 gallon gas/ electric start on gas fired up took about 40 minutes to shut down but water temp is extremely hot and about 160 degrees at tap everything is working as should be but to hot , I believe the thermostat is just set to high ? Thank you

asked by: Michael D

Expert Reply:

Hey Michael,

Typically when a Dometic Water Heater like # DMC33RR is producing water that is too hot it is an issue with the thermostat or thermal cut off fuse. There is a chance it could be a faulty thermostat or that thermal cut off fuse is blown. The cut off fuse is locate near the thermostat and you can test that with a multimeter to insure that is is working correctly. Since it is recommended that this be installed by a professional there is not much troubleshooting we provide for that reason. One thing you could do is try resetting the system by turning it off for a little and back on may give it a chance to reset and resolve the issue.

If those don't work I would recommend reaching out to a professional installer, or Dometic directly to continue to troubleshoot.

expert reply by: Nick S

Michael D.

8/14/2025

Checked Thermo cut off switch and thermostat at hw heater and was told that the thermostat is just making hot water temp too high should replace it . It’s a brand new unit I just received. Can I get a new one sent to me ? Thanks Mike

Nick S.

8/15/2025

@MichaelD That is what I thought it was going to be. I will have someone on our customer service team reach out to you and help get this resolved and get you all set to go.

Michael D.

8/14/2025

Had unit checked thermo fuse good thermostat is working but shutting down at a higher temperature just installed the unit and it is that the thermostat is the high water temperature issue. Can i get a replacement sent to me