Rebuild all my convectors, replaced hoses and fluid for just over $200

Jeff92

I have a 2016 Tab 320 with an Alde 3010 that has never had the fluid changed and it started having a small leak from one of the convectors.  I noticed a tear in the hose but when I removed it I quickly discovered the aluminum was so corroded it ate holes through it. Turned out all of the connection points were that way.

I found it to be hard to get replacement parts (even hoses with the odd diameter where hard to find) that would ship to the US.  At least I couldn't find any, plus I'm cheap so I decided to cut the corroded ends off of every convector and was able to find some hose on amazon that was heat rated and the correct dimension. Between home depot and harbor freight I had everything I needed for cheap.  The only thing I needed was transfer fluid and that stuff is expensive.  I didn't know how much I would need for the flush and didn't want to spend $70 a gallon for what appears to be the same old style of green/yellow fluid that came out of it.  After researching on Alde's website they state alternative fluid that meets their standard.  One of those is VW Group G12 coolant.  The only difference is the coolant is hazardous if ingested.  I was able to pickup Valvoline Zerex HT-12 Pink which is the equivalent but made in the US.

I put two hose clamps per connection.  One at the edge to prevent fluid from getting in between the aluminum and the hose and the second one closer to the end of the hose.  I also added brass elbows to prevent stress of sharp angles.  I flushed the system with about 12 gallons of distilled water before flushing in the coolant.  I had to remove the hoses going to the overflow tank to do the flush.  Also note there is a check valve in the system so if you try to flush the wrong direction it will not flow and you will essentially be pressure testing your system.  Also I combined parts from an electric pump and a hand pump.  While I used the hand pump I think you can get away with just using the electric pump.

If I'm totally wrong and destroy my system that would suck but I would rip out the Alde system and convert it to a generic boiler system from ebay where it would be much simpler to maintain. I did realize I did distilled water instead of deionized water.  That is important for avoiding metals from getting removed.  I might flush again next winter with deionized since the coolant is so cheap.

Tools Needed:
Pipe Cutter
2 Buckets
Hose Clamp Pliers
Ratchet set
Flash flight
Square screwdriver bits


Parts List:
Hoses $80.94 QTY 3: https://www.amazon.com/dp/B09ZDMTVZ2?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
Hose Clamps $9.99: https://www.amazon.com/dp/B08DJ4JS2X?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
Valvoline Zerex HT-12 Pink $50.00 QTY 2: https://www.oreillyauto.com/detail/c/zerex/zerex-1-gallon-pink-50-50-antifreeze/afza/904683
Clear hose $30.00 QTY 2: https://www.homedepot.com/p/Everbilt-5-8-in-I-D-x-7-8-in-O-D-x-10-ft-Clear-Vinyl-Tubing-T10006013/304185175
Hand Pump $8.00: https://www.harborfreight.com/multi-use-transfer-pump-63144.html
Electric Pump $13.50: https://www.harborfreight.com/battery-operated-liquid-transfer-pump-63847.html 
14 gallons of distilled water $17.76: (Walmart or anywhere you can get it) 

pthomas745

Good for you for all this, and your research.  There are some major long threads about the convector corrosion here, and many owners did the same thing you did as far as modifying the convector stubs.

We also have a ton of info about the glycol.  Many owners have stayed with the Century brand glycol, since all the corrosion evidence points to the poor fitting hoses and insufficient clamping of the stubs that allowed the glycol to corrode the convectors over time.

The only thing you might think of adding to your "stubs" is some sort of coating on the stubs to add some extra protection. There have been several different methods used to do this.  

This is the "Corrosion of the Alde Convectors" thread.

https://tab-rv.vanillacommunity.com/discussion/13226/corrosion-of-alde-convectors/p1

We also have long threads and several files about how to do the glycol change.

No matter, you seem to have sorted out a lot!

The ethylene glycol products that owners search for and discover on the European web pages is not approved for the US Aldes, since it is toxic.

The glycol for the US Aldes is "propylene glycol", which is generally recognized as safe.  

Horigan

@Jeff92
How did you replace the snubs on the convectors?

Be aware that the reason ethylene glycol is not approved in the US in this application is because the fluid can potentially contaminate your drinking water in the Alde boiler.  It takes very little ethylene glycol to be toxic for humans.