[Wanderman]

Tom,
Got it.. are they all 12-14v DC or are some 120V?

[kaptain]

Today is my first time turning on Aqua-Hot to check and see if the heating system operates normally, since my purchase of coach 701 several months ago
I see the temperate gauge start to rise, but the display appears to be having a problem - not all digits are displayed fully. See the photo attached. The "6" at the last position is missing the "_" at the bottom, and the 6 in the second place is missing a "|". 
Reading this thread, I learned the replacement part I need is M9113R, which comes with a sensor (sending unit). I see M9113 is available with other color options available too, white (M9113W), green (M9113G), and blue (M9113B) if someone wants a different color. And I found several sources to buy it
https://www.quadratec.com/p/intellitroni...e/in-white
https://www.amazon.com/Intellitronx-M911...B072N8PMXD
https://www.napaonline.com/accessories/i...s/1eaf39a9
https://www.ebay.com/itm/292299385445


   
   
Now, my questions are:
1) do I have to replace the sensor when I replace the digital display? Or can I use the existing sensor and wire with a new display?
2) If the sensor (sending unit) needs to be replaced together with the display, does anyone know the size of the bushing typically used on a Newell coach? I ask this because I see the item listed on eBay, the seller described the sensor bushing sizes are available in 2 different sizes:  "Sending unit (S8013) included (Please send a note to seller if you need a 3/8" bushing because we send the more common 1/2" bushing--otherwise, you will have to supply the bushing on your own);"

[Richard]

When I replaced my display with an Intellitronix unit, I used the existing sensor and wiring. It worked great.

I would at least try that before I removed the old sensor and replaced the new. Remember, if you replace the sensor you will need to partially drain the coolant from the system.

[kaptain]

When I replaced my display with an Intellitronix unit, I used the existing sensor and wiring. It worked great.

I would at least try that before I removed the old sensor and replaced the new. Remember, if you replace the sensor you will need to partially drain the coolant from the system.

Richard, thanks a lot for your feedback. When you say to drain the coolant when replacing the temperature sensor, I wonder, do I need to drain the engine coolant from the rear of the coach or from this plastic container that sits in the same compartment as the Aqua-Hot unit?  
       

The plug on this plastic container looks broken, I need to find a replacement for this. Any thoughts or suggestions?

[hbens]

Joe,
That plastic jug is the overflow container. When your aquahot is cool the level will be low. When the AH heats up and expands the internal coolant goes into this jug. When the AH cools down and the coolant contracts it pulls from this jug back into the AH.
It works like the overflow tank in a car radiator cooling system. Somewhere on the top of the AH tank there is a radiator cap.
I'm not at my coach and I don't have pics of it on my phone so I can't tell you any more.

[Richard]

The big tank inside the stainless cover on the Aquahot is full of coolant (Aquahot calls it boiler fluid). The sensor for the temperature probe is threaded into that tank so that it reads the temperature of the coolant. If you simply removed the sensor, you ARE going to get a lot of fluid pouring out, so the level of the tank must be drained below the sensor level. Easiest way for me is to insert a tube into the radiator cap on the AH tank and siphon it out.

Don’t worry about that plug on the overflow tank.