Macerator toilet system to replace entire vacuflush system

Topic: Macerator toilet system to replace entire vacuflush system (Read 4122 times) previous topic - next topic

Re: Macerator toilet system to replace entire vacuflush system

Reply #25 – March 02, 2025, 10:59:07 am

The macerator pump used in Dometic toilets delivers a flow rate of 3.9 gallons per minute.

If calculation is correct, 1.5" pipe times 3.9 gpm = 18.38 psi. Gallons Per Minute to PSI Calculator Online

This one says 3.9 GPM with specific gravity sewer water of 1.4 (max) = 5.46 psi (but no pipe diameter mentioned). GPM To PSI Calculator – Convert Flow Rate Quickly – This to That Calculator

Oately ABS to PVC green transition cement is my plan (with PVC purple primer as well). These cements are intended for use in cementing transition joints between ABS and PVC materials in non-pressure applications only (25 psi (170 kPa) or less). Oatey® ABS To PVC Transition Green Cement | Oatey

The issue is that connecting to the black 1.5" ABS is outside diameter apprx 2". The white sanitation hose is 1.5" inside diameter.

In the white pic below is a dometic product converting from ABS 2" (apprx) outside diameter to slightly under 1.5 inch outside diameter for the 1.5" ID hose to slip over. The product pictured is white and my assumption is that means PVC.

Once the green Oatey cement is dried, I "could" add a layer of JB weld around the abs to pvc transition. Edit: I had JB weld on hand so reinforced the outer connection of the ABS to PVC connection. Doubt it was needed, but 3 minute job.

From article linked: The ABS to PVC connections with purple primer were as strong as the PVC to PVC connections with purple primer, if not stronger.

Re: Macerator toilet system to replace entire vacuflush system

Reply #26 – March 02, 2025, 08:31:21 pm

Quote from: Michelle – May 25, 2023, 12:23:12 pm

No more duckbills to replace every 3 years (I would guess the macerator system doesn't use them)

They do have them. When I had my toilet apart I replaced them after 9 years since I had the toilet apart.

Re: Macerator toilet system to replace entire vacuflush system

Reply #27 – March 02, 2025, 09:04:42 pm

Quote from: turbojack – March 02, 2025, 08:31:21 pm

They do have them. When I had my toilet apart I replaced them after 9 years since I had the toilet apart.

In this model they label it a check valve. One single 1.5" duckbill is used. Dometic MasterFlush 385311620 check valve (duckbill valve)

Re: Macerator toilet system to replace entire vacuflush system

Reply #28 – March 03, 2025, 09:25:21 am

Ahhh. The Turbo Turd 3000.
I remember it well! Actually, it gave us very few issues. But it would always be my preference to have a direct drop situation. NOTHING kills a good time faster than having the commode go sideways!

Re: Macerator toilet system to replace entire vacuflush system

Reply #29 – March 04, 2025, 07:16:54 am

I'll post before, prep, and after photos.

Control box will go in hamper behind toilet
Toilet should arrive Thursday. Ups Ground out of New York. I just ordered it this weekend.

Inside before pics

Re: Macerator toilet system to replace entire vacuflush system

Reply #30 – March 04, 2025, 07:30:52 am

More items ordered in advance:

180 degree 1.5" U for basement plumbing.

https://www.homedepot.com/pep/NIBCO-1-1-2-in-ABS-DWV-180-Degree-Hub-x-Hub-Return-Bend-Elbow-C5879/100347877?clickid=0bCW53SGKxyKRE5QXuxjq1NJUkswL63WxV%3AS080&irgwc=1&cm_mmc=afl-ir-2003851-1420157-EdgeBingFlow

Picked up a couple extra feet of 12 gauge stranded red and green wire (hot and ground) in case needed from existing wiring to control box. edit - it was needed). Control box itself uses red hot, black ground. Also a short 20 amp fused 12 gauge wire. Already a 20 amp resettable breaker in basement, just a redundant fuse to the control box.

2 feet 1.5" sanitation hose flexible for inside, in case needed versus existing. Edit - it was needed, but 1' enough in my case. Existing sanitation hose does not bend easily, and might be too short. New toilet sanitation discharge will go from verticle to rear discharge under hamper. Edit: the delivery box included a 90 for this - but it did not work out as detailed later).
Dometic/Sealand | 1 1/2" MaxFlex Hose (per Foot) | 306341116 - Environmental...

Existing toilet 4 bolt to floor, new 2 bolt to floor. Drill bits tile: Amazon.com: KURSTOL Masonry Diamond Drill Bit - 10pcs 1/4"-1/2" Concrete...

Clamps for sanitation hose, basement and inside: Amazon.com: Roadformer 1.5" Worm Gear Hose Clamp - SAE 24 Size, Full...

As fulltimers we want the least possible downtime for this change. I'd rather have leftover / un-uneeded parts than downtime. We are in a small town with an smaller sized Ace hardware.

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.

Re: Macerator toilet system to replace entire vacuflush system

Reply #31 – March 04, 2025, 07:20:20 pm

Before project photos, basement.

Saw here in our Escapees co-op park I used to cut the ABS pipe.

Limited height (apprx 5") with lots of obstructions (hoses, pipes etc) in basement where removing old ABS pipe and inserting new pipe. (bottom pic)

Approx 19" of abs pipe and 1.5" sanitation hose in the limited height part of basement above the black tank (to left) and grey tank (to right) (pic 2)

You can just see the sanitation hose behind the white wire tie, and the drop into blank tank is behiind the first drop, back where I put the yellow foam for location. (pic 4)

Better pic of sanitation hose start postion (with clamp on it), and drop into black tank behind that (where yellow foam is). (pic 3)

Pic of ABS and sanitation hose leaving above tank area into more open space. (pic 5)

This is the rest of the abs piping. sanitation hose, and vacum geterator. All will be removed that is in this pic. (pic 6_)

Re: Macerator toilet system to replace entire vacuflush system

Reply #32 – March 04, 2025, 07:36:52 pm

The old plumbing in post immediately above is what concerned me most about doing this project. I spent a bunch of hours figuring the solution, planning, and getting all materials in advance so no dead ends on install day. Only a small hardware store here.

Next pic will be "most" of the plumbing solution to replace everything in the post just above.

The drop pipe into black tank is not inserted into the grommet. 1/4" will be exposed when fully inserted.

The open end of the abs 180 degree turn will have the fitting to adapt to 1.5" inch ID sanitation hose.

The middle part of bottom pic is the adapter to glue into the ABS. Purple primer on the white part, then green transition cement on both is the plan for now to glue the adapter.

The 180 will be on top of grey tank to left of "wall" in pic 5 above. May put a foam pad under it.

"Likely" will have to cut the ABS mess in the open area to pull the rest out for limited space area.

Then just cutting the sanitation hose to correct length (I have a hose cutter up to 1 5/8)

edit: go 14" on straight pipe in pic not 12"

Re: Macerator toilet system to replace entire vacuflush system

Reply #33 – March 04, 2025, 08:18:42 pm

Install day plan:
Bleach mix through toilet into plumbing and vacum generator.

Turn off water to toilet (outside bay)

Service mode toilet to let vac generator suck everything out and push as much as possible into black tank

Power off to entire vacuflush system (toilet/vac generator), then pull power connector in basement off vac generator

Pull old toilet out, clean all around, run wiring to masterflush status sensor around the corner and up to where vacuflush display panel is now. Edit: no status display with flush handle version of masterflush - and not needed.

Install control box in hamper (location already chosen), run cables / wiring out rear discharge hole in wood

Use provided template for new toilet exact postion (did 'nt use, had to adapt offest). Drill new mount holes

The existing 1/2" NPT water supply line is plenty long to reuse (used new hose
that came with masterflush)

Plan the new discharge hose and mount to toilet

Mount toilet

Outside remove white sanitation hose from vac generator, place into bucket

Test flush twice before cutting old ABS plumbing in basement (in case have to remount vac toilet to solve some problem)

Remove old basement abs, and install new ABS pipe/connect trimmed sanitation hose

Remove vac generator (10 minute job)

Lots of details and prior planning. Fulltimers, want it all done in one day with few issues along the way. I decided NOT to hire help. New toilet and old approx 68 ppounds each to get in and out stairs will be fun.

One more "just in case" part ordered. Not 100% sure of the the other one. Dometic/Sealand | Custom Hose Adapter | 385320017 - Environmental Marine

Re: Macerator toilet system to replace entire vacuflush system

Reply #34 – March 04, 2025, 08:24:06 pm

Looking good ... thanks for all the pictures and updates!

When you pull the old toilet (in case you never have), the zip ties in the floor mounting holes were OEM. They were there when I removed the toilet to change the lower seal and one of the linkages. In fact I may have added a couple of more to get the base to cinch down, no one wants a wobbly base

Re: Macerator toilet system to replace entire vacuflush system

Reply #35 – March 05, 2025, 07:09:06 am

One function we will lose is full tank toilet shut down system.

The vacuflush has a full tank sensor that stops the toilet from flushing. In seven years plus, we have only hit that full tank shutoff 2 to 3 times when boondocking or in parks with electric and water but no sewer drop.

Dometic sells a optional full tank sensor system for the Master Flush macerator. We will not get it. No access to top of tank to add it to black tank, hassle running wiring, and some people have had issues with false system shutdown and clipped the wires.

I had added See Level Garnet tank `monitoring in the past, one display in basement by dump valves, one inside coach.

I will replace one of the two monitors with blue tooth capable Garnet BTP-709. Same size display, just some wiring change right at monitor, so easy change. Introducing the All-New 709-BTP7 – Garnet Instruments

BTP-709: Available for both iOS and Android devices, the app enables users to access real-time tank levels, set customizable alerts for when tanks are too high.

We only use fresh, grey, black, and battery functions. We will just ignore the alt and water pump switch on the new monitor. We will set alerts via blue tooth app for fresh, black and grey tank levels.

Existing monitor to replace:

Re: Macerator toilet system to replace entire vacuflush system

Reply #36 – March 05, 2025, 05:50:31 pm

For anyone in the future doing this conversion, these two 1.5 hose adapters (1.5" OD for the hose end) are exactly the same.

If using all ABS except for the hose adapter, buy the single adapter instead of the 90 degree and 2 hose adapters.

90 and two adapters: 90 degree Bend Kit, 1.5" - Marine Sanitation & Supply
Single hose adapter: Dometic/Sealand | Custom Hose Adapter | 385320017 - Environmental Marine

Re: Macerator toilet system to replace entire vacuflush system

Reply #37 – March 06, 2025, 11:04:14 pm

Pic 1" control box and wiring harness(s)

Pic 2: back of master flush after I changed discharge from bottom eject to rear eject Edit: had to change back to bottom discharge, details in later post

Pic 3: in the box were fittings for bottom discharge, rear discharge, and 1"/1.5" santitation hose connections. Pic includes the "duck bills" (one included and set for bottom discharge as delivered).

Same exact duck bill as used in Vacuflush. I have 4 on hand which were for future maint on the vacuflush, so I have 5 total. We are set for many years.

Pic 4: I "thought" a status display would be included for the masterflush to replace the vacuflush staus display pictured.

Not included in box - optional seperate order item. Not required since we chose the flush handle version and did not do the tank full seperate purchase.

I will blank out the vacuflush status display in the next week.

Re: Macerator toilet system to replace entire vacuflush system

Reply #38 – March 07, 2025, 07:02:24 am

To change from bottom discharge to rear discharge takes 2 adjustable water pump pliers (joint pliers).

The duckbill sits between these 2 white 1.5" fittings pointing down.

Unlike the vacuflush, anything passing through the duckbill has been liquefied by the macerator, so blockages extremely unlikely.

Edit: due to location of the discharge connection on the Foretravel, leave it bottom discharge, buy a 90 Degree 1.5 inch hose connection. Then cut a few short sections of sanitation hose to use for hookup.

Re: Macerator toilet system to replace entire vacuflush system

Reply #39 – March 07, 2025, 10:26:21 am

Thanks for all the details and pictures ... quite the undertaking

With all the parts on hand the real fun part is next !

Re: Macerator toilet system to replace entire vacuflush system

Reply #40 – March 08, 2025, 10:03:53 am

Control box installed in hamper behind toilet:

Re: Macerator toilet system to replace entire vacuflush system

Reply #41 – March 08, 2025, 10:18:30 am

The 1.5 inch sanitation hose goes on some fittings easily, and some fittings with extreme difficulty. Dometic says to use dish soap --that works only on the easy fittings. A hair dryer and heating the end of the hose, then adding the dish soap makes it easier.

One unexpected issue: The vacuflush discharge hose connection is at floor level, and centered on the old toilet. The flushmaster discharge is up quite a few inches, and on right side of toilet as viewed from the front.

Santiation hose is not very flexible at all, especially short sections. I had to mount the new toilet offset to the left compared to old toilet. Note in pic 2 the old mount holes on right side compared to new. Required a 90 degree 1.5 inch fitting, plus 2 sections of sanitation hose even with the offset mounting.

For the 90 degree hose fitting, I ordered a inexpensive Amazon product. It worked, but I am surprised it is not seeping. I'm going to buy a different one to have on hand "just in case" as this size hose fitting is not in all hardware stores.

Not expensive, may or may not be better: https://www.homedepot.com/p/Apollo-1-1-2-in-Barb-Insert-Blue-Twister-Polypropylene-90-Degree-Elbow-Fitting-ABTE112/300814157#overlay

https://www.supplyhouse.com/Everflow-PXLN0112-NL-1-1-2-PEX-x-1-1-2-PEX-Brass-Elbow-Lead-Free
Says for pex only, not sure of the weight on the toilet connections

Others that may or may not work:
Amazon.com: Universal Aluminum Radiator Hose Connector | 90 Degree Elbow |...
Amazon.com: Yoebor Stainless Steel 304 Sanitary Hose Barb 90 Degree Elbow...

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Re: Macerator toilet system to replace entire vacuflush system

Reply #42 – March 08, 2025, 10:52:14 am

Quote from: steve – March 04, 2025, 08:24:06 pm

Looking good ... thanks for all the pictures and updates!

When you pull the old toilet (in case you never have), the zip ties in the floor mounting holes were OEM. They were there when I removed the toilet to change the lower seal and one of the linkages. In fact I may have added a couple of more to get the base to cinch down, no one wants a wobbly base

I had to add zip ties into the 2 new holes for new toilet to get solid connection.

Re: Macerator toilet system to replace entire vacuflush system

Reply #43 – March 08, 2025, 11:59:07 am

Interesting that the outlet is not centered, good to know. Wish they would list the min bend radii for the sanitation hose instead of just saying "flexible".

Glad to know the zip ties remain

Re: Macerator toilet system to replace entire vacuflush system

Reply #44 – March 08, 2025, 03:40:02 pm

In the basement.

Before/after Vac generator gone. New plumbing above the black and grey tanks.

On the right side, the new 180 degree return from toilet to black tank is braced top and bottom so it can't bounce or shift around.

On the left side, the drop into the black tank has a piece of yellow foam jammed above it so it can't shift upward out of the tank.

Re: Macerator toilet system to replace entire vacuflush system

Reply #45 – March 08, 2025, 04:38:42 pm

New system is much quieter than the old toilet/vac generator.

Much less complex as will, with less to go wrong. Parts readily available, and if professional service needed more RV techs familiar with the masterflush/macerator toilets.

We are happy we did the change.

Re: Macerator toilet system to replace entire vacuflush system

Reply #46 – March 08, 2025, 05:16:13 pm

I would do the same as what you did if I had your design but we have the "plop & drop system.

Re: Macerator toilet system to replace entire vacuflush system

Reply #47 – March 08, 2025, 05:18:08 pm

"Plop and drop" beats complex systems.

Re: Macerator toilet system to replace entire vacuflush system

Reply #48 – March 08, 2025, 06:22:57 pm

Quote from: AC7880 – March 08, 2025, 04:38:42 pm

New system is much quieter than the old toilet/vac generator.

Admit it ... you are going to miss the Ka-chunka-Ka-chunka-Ka-chunka

Congrats on getting the job done, that was a lot of work!

Re: Macerator toilet system to replace entire vacuflush system

Reply #49 – March 09, 2025, 09:35:50 pm

The flushmaster is designed to add water by lifting the handle, and flush by pushing down. It was doing just the opposite.

Red wire is flush, black add water, white ground.

First pic is flush handle wiring before I swapped black and red wires, tightened the wire tie for the wires to stay connected, and improved the strain relief wire tie.

2nd pic is toilet flush handle now working as it should be. If you order a master flush check the wire locations before installing (I had to pull the toilet to fix it).

Links to parts photos:
Dometic/Sealand | 8700 Series Flush Handle Assembly | 385311704 - Environment...
Dometic/Sealand | Flush Handle Rocker Switch | 385311290 - Environmental Marine

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