The master head won't drain. It fills up and then over a few days slowly drains to empty. I have run a few gallons of CLR into the bowl with no success. Just poured a gallon a muriatic acid into the bowl, don't know if its drained through or not as I had to leave.

Looks like 2" PVC piped with 90 angles under tub into engine room up to galley maid pump on starboard side engine room floor. Then through a 1" line with a siphon loop, disappears through floor along strake and re-appears in genny room to black water tank.

If I attached a line to the existing 1" line, what could I force through it to de-calcify or unclog if that is where the issue is?

Sky mentions that the old line is held up with cushion clamps every 1', so yanking it out would be a major PITA even if you could access it all. So it the procedure to abandon in place and pull through another line?

Was thinking about replacing galley maid with a new Atlantis Freedom. I'm thinking that if I have to spend $500 having it rebuilt, better $1k for new. Anyone have any experience with these?

thx