RM69 Holding Tank Problem

[multihullsailor6]

On my boat I have a RM69 toilet with the 25L buffer / holding tank.

Despite all the valves being in the right position and using the bowl stop my holding tank is not emptying!

I am not getting any help from Raske & Van der Meyde themselves, emails are not being answered - have they gone bust?

Has anyone experienced this problem - is this a design fault?

I can only think of two problem areas:
1) A faulty RM 3-way valve (but it works in the other two positions)
2) The loop in my exit hose is too high - the maximum height of the loop above the three-way valve exit is 60cm - is that too high?

[peghall]

Most likely your tank vent is blocked. That will cause the pump (pumpout or o'bd discharge pump) to pull a vaccumm that prevents anything from being pulled out of the tank. A particularly strong pumpout can even pull hard enough to implode a tank.

The two most common locations for a tank vent blockage are the thru-hull and the connection at the tank. Reaming both out should solve your problem.

[DtM]

We had the same problem and a couple of swift and solid hits to the tank near the outlet unclogged the "stuff" at the base of the tank and to great relief the tank emptied (we were offshore so not pump out). If there is stil some "space" in the tank try pouring ina bucket of water through the deck fitting to stir up the bottom of the tank.

[bluetriguy]

peghall has it - the vent is probably blocked. A real solution would be to switch your septic system entirely to something like (or actually a) Airhead. This is a composting toilet that doesn't even have a black water tank (so no pump outs ever). I switched on my boat (not to the Airhead brand - but it's great) and have never looked back. Lots of folks here probably will make comments cause let's face it, bodily excrement jokes are good fun, but a composting system really is amazing in a boat. No stench, no flushing (so no pumps or hull penetrations) and no odor from poop saturated hoses. Two people can use the loo for a couple months before needing to do anything at all. Since AirHead can probably explain it better I'd suggest you g**gle them. Again, I don't own one (mine was built by my grandson on a Norwegian design) or have anything to do with the company but it is the future of marine toiletriness... what? Oh. OK I'll stop. (seriously, look up composting toilets on g**gle) - AND you can actually install a bidet 'on top'...

[DeepFrz]

Pour in a bucket of hot water and some High Efficiency Detergent. Sail for a while and then try. That will help quite a lot but you still may have to take a dive with a wire to get the flow started.

[DeepFrz]

I understand composting toilets are great until you get a bug infestation.