AquaHot heat exchanger

[rheavn]

I am currently working on the heat exchanger that services the vents in the dash & salon. My fan has not worked for this zone since I purchased the coach. It appears the motor is bad. For any one who may have this problem in the future the heat exchanger is a Komfort EXX-D16-200. There is a motor kit that is available- Komfort EXX-D15-241. The cheapest prices I have found on AquaHot parts is from this guy who I have bought from before: http://www.parts.rvhydronicheaterrepair.com/

If anyone has replaced this motor on this heat exchanger & has a set of procedures I would sure like to have a copy.

Thanks...........................

[Neweller]

Steve, what is the model number for the Aqua-Hot itself? Does it start with AHE-? or something?

[rheavn]

Model # 431 XE-12 Manufactured in 1998

[tuga]

Good post Steve - I'm sure sooner or later we will all need that info

Thanks!

[rheavn]

In learning more about our AquaHot systems Roger Berke sent me a AquaHot service bulletin that describes how the dual elements are handled in our AquaHot systems. There is also a wiring schematic that shows how the two element system is wired. The high limit thermostat is rare & I believe only used in Newells--at least in this configuration. AquaHot part number is ELE-WHL-402. List price is $175.00 This bulletin effects at least '94 to 2000 Newells with this AquaHot system.

Couldn't figure out how to attach file as it is too big. If you want a copy of the service bulletin send me an email or private message.

[Neweller]

Steve, we are working on a major update for the forum and with it, we planned on setting something up to accommodate the upload of diagrams and such.

Also, I believe there is a possible recall on Aqua-Hot water heater units of your year. Regarding the premature failure of the burner tubes. Not sure if yours had already been addressed or not. I do have a link pertaining to it.

Ken

[rheavn]

Received the new motor yesterday & installed it today. System now works as designed. It took 2 1/2 hours to remove from the coach, install the new motor and reinstall in the coach. It looked like the heat exchanger case would split in half, but I didn't figure out how. I was able to remove the bottom squirrel cage fan from the bottom & then remove the motor through the bottom, while leaving the top squirrel cage fan in place. Reassembly in reverse went very easy.

One thing on the AquaHot systems that gets overlooked is checking the coolant PH. Since the coolant system is a closed system there is no changing interval, but older coolant can turn alkaline. PH test strips are available and takes only a minute to check. This check should be done at least annually. As long as the test is above 7.5 PH you are good to go. If it falls below 7.5 PH it is time to change the 16 gallon system.

Hope this helps someone....................

[Richard and Rhonda]

Steve,

The rust inhibitor in coolant can also weaken with time. After working on another owners Aquahot and seeing first hand that the boiler had rusted out from within, I added a pint of coolant rust inhibitor to my system just for grins.

It's kind of a mystery to me why all the engine manufacturers recommend changing coolant anywhere from 3 to 10 years. As a ChemE I know ethylene glycol does not go bad or deteriorate with time, so has to be one of two things. Either the additive package which contains rust inhibitors and pH buffers is used up, or the system is contaminated with wear products from the coolant system. Perhaps both. Just wondering out loud.