How I came to do the Alde glycol maintenance DIY

jimcenname

I completed my first DIY replacement of Alde glycol in my 2019 T@B 400 with the reservoir in the front left. I purchased a setup of a small pump with hoses, copper pipes and plugs ($150) from a T@B owner on Facebook (Mark Johnson.) At the recommendation of Truma/Alde I purchased the Adle glycol on Amazon ($68/gal.) I purchased 5 gallons and install about 3.6. I'll keep a gallon to top off.

For this service I previously employed nuCamp (~$500), Truma/Alde ($600) and John Schilling (~$400) (San Diego region, nuCamp factory trained.) I learned what I liked and didn't like about each of their processes and I chose to DIY this time. I got what I wanted.

I live in my T@B and the heater and water heater get used every day. I replace my glycol every 12-18 months. I switched from Century to Rhomar/Alde glycol with my second glycol flush. Due to convector corrosion nuCamp replaced my Alde hoses and convectors in 2023. 

qhumberd

Thanks for the post @jimcenname. It seems inevitable that corrosion is going to impact these connections at some point. Is Truma pretty convinced that regular changes with the Rhomar will prevent future corrosion? I am sure your corrosion service for the 2019 400 involved a fair amount of work to access the convectors, which had to be pricey. But when I think about maintenance on a regular house HVAC and water heater, it might be not so bad in comparison.

jimcenname

I had early signs of corrosion, even before the first service. I hoped that switching to the new glycol would stop the corrosion but it didn't. Ultimately I had to replace the convectors and hoses. That appears to have worked. As I understand it the corrosion inhibitors in the glycol diminish with time and the 2 year interval assures sufficient protection. 

pthomas745

There have already been a couple of reports of the "Rhomar" trailers having corrosion in places where the clamping is not sufficient to prevent glycol intrusion under the hoses at the "stub ends".  

In the newer trailers, (I want to say after 2020) the design and setup of the Alde hoses and convectors is quite different compared to the Alde 3010 trailers, with extensive hose runs leading to poorly fitted and clamped convector stub ends, or at places like the "non-return valve" next to the Auto Air Bleed Valve.

This thread has a discussion about this, and a picture of the owner's 2023 check valve that corroded and leaked. If there is glycol under a clamp between the hose and the aluminum, it will corrode over time, even if you change the glycol once a month.

https://tab-rv.vanillacommunity.com/discussion/19751/any-verdict-on-blue-rhomar-water-glycol-and-corrosion

jimcenname

When nuCamp replaced my hoses and convectors they used hose plastic couplers in place of aluminum. Of course the convectors remain aluminum. The recent photo below is of the convectors in the kitchen cabinet. It's representative of others I have recently inspected. It looks good to me, after 2.5 years of use.

AnOldUR

For additional protection, I followed the recommendation to put two spring clamps on the ends of the convectors. One as close to the end as possible to lessen the chance of glycol getting between the hose and aluminum end on the convector.