Vacuflush , mineral buildup

Been wrestling with a recurring problem of the vacuum pump not shutting off.
I changed the joker valves about a month ago and noticed that the two before the pump were clogged with chards of mineral deposits. After cleaning the hose and pump, replacing the jokers, it has been working great until recently.
Again pump runs continuously. Pulled it apart today and found same issue. Jokers crammed with mineral " wafers ". Cleaned it all up , reassembled and works great again.
What can I do to dissolve the mineral buildup in the system? If muriatic acid, how much and how often?

Thanks, Bill

Do you have fresh water flush?


Vinegar might do it.


I had VF for 15 years and never had a problem like that. Always flushed multiple times with clean water after each trip and finished with KO left in the hose.


Any acid will kill the bugs in whatever you use to treat your tank.

I use this dont know if you can get it in US?
http://www.bunnings.com.au/clr-1l-calcium-lime-rust-remover_p4460670

Muriatic acid should only be used to CURE, not prevent, mineral buildup. A cupful of UNDILUTED (turn off the water pump) distilled white vinegar flushed through the system once a week should prevent it. Wait 45 min to an hour--no longer...then follow with a bowlful of clean water.

Diluted vinegar won't help much...It won't hurt soft rubber (your duckbills or joker valve in other toilets) if it's just flushed through and then rinsed out after an hour...However, soft rubber left to sit in vinegar even overnight will swell up and distort, so the rinse after an hour is very important.

This is usually a result of not flushing enough water through the system per the instructions. It can also be a result of an improper installation, a situation I confronted when I bought my boat.. too many sharp 90 degree turns in the hoses, outlet from vacuum tank on the side, not in bottom (tank mounted wrong), pump above vacuum tank, not below. Once I remediated all that (and it took a year for it to evidence itself with the same mineral chunks as OP) had many years of carefree service, living aboard full time, master stateroom head.

This is the master stateroom head and we do live aboard. It is a fresh water flush. I checked the pump and vac tank relationship, the outlet is on the bottom of the tank, but is about six inches lower than the input side of the pump.
The outlet side of the pump has to go uphill about another six inches before going forward ( in a declining pvc run) to the holding tank.
will try to post a pic of the detup.

Thanks all for your input.
Bill

errrrrrrrrr........ setup.

and a pic

How long do you leave the pedal down after each flush, Bill? Minimum after JUST urine (no TP) is 3 full seconds...after solids and/or TP at least 7 seconds. At least half a bowl of water should be added ahead of solids.

If you're using much less than that, your problem isn't hard water minerals, it's urine crystals. White vinegar can prevent the buildup, but using a little more flush water to rinse out the system is a lot simpler solution. Cal is right: most problems with V/Flush are a result of using too little flush water...And I don't care what SeaLand claims, a pint of water/flush is nowhere near enough to keep hoses and the vacuum pump rinsed out. I've always found that running a full bowl of clean water through it once a day just about eliminates all problems that aren't due to equipment failure.

Thanks Peggy, I think you are right on. We only use the vacflush for urine and I think we are a little light on the flush water. We have gotten in the habit of using the forward head ( sealand master flush) for the other business dooties.
The forward head is very close to the holding tank.
I think I'll do a CLR 30 min soak and then flush ,flush,flush.

Bill