My Oasis is "making " fluid

[newmarokie]

Okay, I know it is not making fluid. I have the wet bay torn apart replacing tees, elbows, and valves. I had the pressure off of the system for about 75% of the time. When I check in the morning for leaks one of my leaks was the overflow tank overflowing on the Oasis. I put a clean jug under the overflow tube and left it overnight. The next morning the 2.5 quart jug was brim full. I siphoned about 3 quarts out of the overflow tank and started the Oasis and let it warm to temperature. I siphoned another quart of fluid out. I turned the fresh water off and left it overnight. This morning it was up another 1 1/2". I took the radiator cap off of the tank and it had light pressure on it and was completely full. With the system powered completely down the domestic pump was running. They only two things I can think of that is happening is (hopefully) a bad radiator cap or a bad heat exchanger. I am under the impression that the heat exchanger is two completely separate lines running through the aluminum fins so there can't be any incursion between systems. I am going to try to get the radiator cap replaced locally and see if that cures the problem. Any thoughts or advice would be appreciated.

 

[Richpatty]

Do you think it looks like oasis fluid? And is it watered down?

 

[SteveMA]

consider air bubbles in the oasis plumbing. temp (overnight) will cause expansion and contraction of volume. I recently purged my oasis system for air bubbles (did not see much if any) but the overflow tank variation has subsided significantly.....

 

[Sealyn]

Boiler fluid circulates thru the domestic hot water heat exchanger. Sounds like you have an internal leak in the heat exchanger allowing fresh water into the boiler fluid.

 

[newmarokie]

I am refilling right now with a new radiator cap. Fingers crossed. Sealyn , I really think the heat exchanger is not “wet”. I think it is two separate lines. One for boiler fluid and one for domestic water. The heat transfers from fluid to water across the aluminum fins. A wet system is like the oil cooler on a diesel engine. A line failure puts water in the oil or oil in the water

 

[newmarokie]

What I really need to know now is should the domestic water loop pump be running when everything is powered down

 

[Texas Clodhopper]

The one confusing thing is that with your water supply off, you still had fluid built up in the overflow tank.

I just replaced the Oasis DM 12 module because water was leaking into the thermal fluid, causing the overflow tank to overflow. According to Bryan with Oasis, the only way this could happen is that the heat exchanger is leaking. FYI, the DM12 module is $2500, and replacing it is not for sissies.

 

[Richpatty]

So you had to replace the DM12 due to the heat exchanger leaking? Interesting. I have the NE-S so I don't want to think about if mine went...where the heat exchanger is integrated. I guess the whole unit would have to come out... I will block that from my mind for now.

 

[Texas Clodhopper]

To replace just the heat exchanger, I would still need to remove the distribution module, basically gut the unit to get to the heat exchanger, then put it all back together and reinstall. Trust me, lying on my stomach or side in a confined space was no picnic. Just removing and reinstalling all the hoses was crazy. Of course, all of the hoses had spring hose clips except for the fresh water in and out lines, which were Pex. At least I'm now the proud owner of a Pex tool.

 

[newmarokie]

hopper, was that for the entire module, or just the heat exchanger? Is just the exchanger an option to your knowledge?

 

[newmarokie]

Sorry, I didn't see your last post

 

[osuallen]

I am refilling right now with a new radiator cap. Fingers crossed. Sealyn , I really think the heat exchanger is not “wet”. I think it is two separate lines. One for boiler fluid and one for domestic water. The heat transfers from fluid to water across the aluminum fins. A wet system is like the oil cooler on a diesel engine. A line failure puts water in the oil or oil in the water

Actually the HX has 3 completely separate pathways. 1. Domestic water. 2. Oasis fluid. 3. Engine coolant.

 

[Texas Clodhopper]

Actually the HX has 3 completely separate pathways. 1. Domestic water. 2. Oasis fluid. 3. Engine coolant.

And where my DM is located, removing the engine hoses was the most difficult part.