Porter - I run freshwater through the pump so scale/lime isn't really affecting me. Pump still dies prematurely.
The Frigoboat UK spec'd pump (4105-343 Flojet) is 24v and flows 3.3gpm. The Frigoboat compressors require 1gpm per the VECO documentation. Per my earlier post from Penguin UK, the concept is that a 24v pump running on 12v will be acceptable for continuous duty - that is not the case obviously.
Rudolf - Mohammad Shirloo, in the Med, has the same longevity as you. Apparently his pump has lasted over a decade. But two things help explain that:
1) Neither of you are full time.
2) Both of you are in the cooler Med.
Oliver said that after he changed the insulation on his galley freezer, his pump was running 15% (or thereabouts) duty cycle in Portugal. Now that he's in the tropics, it's up to 75% duty cycle. This mirrors my experience as my Flojet pump lasted far longer when I was in the Med.
It appears the combination of higher ambient temperatures and higher water temperatures when he left the Med increased his pump usage by 5x.
Curious - do you run the freezer? We often run two fridges and the freezer. With the three "unsynchronized" compressors, the pump runs nearly 24/7.
And with longer continuous running periods, the brush temp goes up a lot. And above a certain temp, brush wear appears to be exponentially higher.
Based on this, we are trying to find a brushless solution.
