Quote: the water heater and/or the water pump allowing you to blow out the lines and refill with antifreeze.

... so when you live in the colder areas how often do you change your antifreeze??

Every winter when we winterize... I was referring to the fresh water system. Some folks add antifreeze after draining.

Actually I hate the taste of the antifreeze and it takes forever to rinse out in the spring. I just drain and blow out the lines on my coach.

As for engine coolant, the Cummins has a coolant filter which has internal additives that dissolve over time. The filter has a bypass valve and can be changed with mininal coolant loss (just what's inside the filter)

As long as the coolant tests OK you can run it for a long time. I would change every five years anyway.

quote:

I would change every five years anyway.

Not me. I prefer Ethylene Glycol. Been in my home heating system for over 20 years. No need to change it if you do not let any oxygen in to break the ethylene glycol down. I am sure there are folk that agree with you Steve VW. My coach holds 17 gallons and I have no intention to change it since it is rolling around 5 years now. Coolant recovery plastic bottles work for me. I just do not change antifreeze till there is a leak. Same goes for air in my tires. I do not change the air in my tires till there is a leak.

All coolants except the pink RV stuff are ethylene glycol based. Only difference is the additive package. (Pink stuff is propylene glycol) They used silicate based additives until recently, lately they use some other stuff to increase protection of aluminum components.

I would be concerned with internal corrosion in the engine over time. The coolant filter in the Cummins has a sacrificial additive that releases over time. Cummins recommends regular coolant additive testin to prevent corrosion and scale buildup.

The house system runs lower temps. The engine has cast iron, aluminum and the radiator can get scale in it. The dissimilar metals promote internal corrosion and scale formation.

Five years is plenty long in an engine.

Do NOT use the pink stuff. It should be called Death Cool instead of Dex Cool. Really screwed up my 98 V-6 Chev engine in a S-10. It would go to a rolling boil in 3 blocks ! Just google - gm dex cool lawsuit - and read the horror stories. I'll spare you the details but it was very hard to get it flushed out of the engine and radiator. It turns to orange goo! Use GREEN ANTI-FREEZE. There has never been an engine failure caused by a coolant system full of 50/50 GREEN anti-Freeze. Lou, FMC #120

Propylene glycol was never meant for engine coolant. It is used for freeze protection in fresh water plumbing.

As you discovered it will not work at engine operating temperatures. It is used in water systems because it is considered less toxic than ethylene glycol. (Neither are good for you, they both make the water taste like s#!t and are hard to rinse clean. Personally I prefer alcohol products for the water lines, or just drain and purge with air.)

My local shop refuses to use DexCool, although other long-life products are safe. I've used NAPA's product in all three vehicles without issues.

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As for engine coolant, the Cummins has a coolant filter which has internal additives that dissolve over time. The filter has a bypass valve and can be changed with minimal coolant loss (just what's inside the filter)

Sleeved cylinder engines require extra additives not needed by native blocks.