i installed a 15 tube evacuated solar hot water tube heater
been working great 13 years now

my question is where the copper tips go into the manifold with the thermal transfer grease, how often does this thermal grease need to be cleaned of and replied.

i have not pulled a tube out and looked so i don`t know what condition the grease is in?

any ideas?

Cheers,
Richard

picture of the tubes in the manifold (yes i did install lagging on the copper joins)

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HI Richard, I have a solar hot water system. It uses twin walled glass tubes with a tank attached. I recently moved mine to a better place on our roof.
I tried to remove the tubes but they seemed pretty fixed in place by the rubber grommets. Rather than create leaks I just moved the whole system as on piece.
I would think that the rubber grommets on your system would be similarly tight on the glass.
I have seen heatsink compound go dry and hard over time, unfortunately I don't have an answer to that question.
I would go with , if it is working leave it.
Pete

i don’t think i will create any leaks as such by removing a tube as my system uses a header/manifold system,  (1 litre manifold and a pump to a lower 200litre holding tank) and the tips of the tubes just poke into the copper jackets where the thermal paste hopefully is still there and doing it`s job

I do have 4 spare tubes, so if i do venture into looking at the condition of the thermal paste and i break a tube, i can replace it.


but barring any other ideas from others.... yeah it isn’t broke done fix it!!

Cheers,
Richard