My Oasis is "making " fluid

[Texas Clodhopper]

Probably even worse if Oasis went to the engine coolant.

Well, gee, thanks!

 

[d23haynes57]

The weak link in the Oasis is the domestic water heat exchanger. The usual failure is due to freezing. Freezing it will not even try to put up a fight. The ease of this failure is the main reason the units call for non-poisonous boiler fluid. The failure will usually only be internal, you will not see external leakage unless you really swelled it up. To test, you can use a cooling system pressure tester on the boiler cap. If turning on the domestic water raises pressure in the boiler you confirmed the failure. The heat exchanger is a some what off the shelf item. You can source elsewhere and if you want to be creative you can also use a larger one.

 

[Texas Clodhopper]

The weak link in the Oasis is the domestic water heat exchanger. The usual failure is due to freezing. Freezing it will not even try to put up a fight. The ease of this failure is the main reason the units call for non-poisonous boiler fluid. The failure will usually only be internal, you will not see external leakage unless you really swelled it up. To test, you can use a cooling system pressure tester on the boiler cap. If turning on the domestic water raises pressure in the boiler you confirmed the failure. The heat exchanger is a some what off the shelf item. You can source elsewhere and if you want to be creative you can also use a larger one.

The HX may be the weak link but I assure you, mine didn't fail due to freezing. You're correct, the only external leakage was from the overflow tank. As far as replacing the HX, I would need to remove the DM just to be able to get to the HX, and regarding putting a larger HX in the DM, I would guess that would be impossible to do because of space limitations. I guess you could mount the HX external to the DM, but then you've created a plumbing nightmare.