Dometic VT2500 vacuflush toilet

[John and Liana Fox]

On 10/08/2020 at 09:20, jonesthenuke said:

The other spare which will save money on these toilets is the microswitch used on the cassette present and pressure switch positions. This is the item required from RS as a fraction of the Leesan price at  £4.23 plus VAT etc). These switches do wear out and cause all sorts of problems. http://uk.rs-online.com/web/p/door-interlock-push-button-switches/0575539/

Jones, 

I have ordered two new microswitches, although mine seem to be working. Thank you.

John Fox

[John and Liana Fox]

Hello Pearley, Jonesthenuke and fellow toileteers,

Right. I have been to the boat. On switch on, the toilet pump works for about fifteen seconds, then stops. Yellow Led on, green led off.

 

The vacuum built goes as Some water is sucked into the tank, but The Pump Does Not Switch On Again, and doesn’t if you press loo pedal. The only way to get the pump on again is to switch off supply, wait, then switch on, when the above happens again.

If holding tank off, red light on.

If magnet held near reed switch, it clicks and Red Led comes on.

If holding tank off but tank on micro switch pressed, yellow led comes on, but no motor after that initial 15 seconds. There is no vacuum, but motor does not come on. If you move the vacuum switch micro switch to stop it being pressed by the lever, the Green Led does come on, but no motor.

So ...... as far as I can see, all three switches and motor operate. The motor does not stay on Long enough, so a Full vacuum is NOT created in the holding tank to make the vacuum switch operate and switch the pump off. 
1. Why does the pump cut out after 15 seconds and not come on again, so a vacuum is Not maintained for the loo to operate?

 

 

[pearley]

I did have a situation with mine where the pump micro switch was worn so it wouldn't work when the cassette was inserted but would if it was fully pressed by hand. Does it still stop after 15 seconds if you just hold switch in?

 

As you have changed PCB then it looks like a pump problem.

[jonesthenuke]

The other cost saving trick with Vacuflush loos is to clean out and refill the filter cartridge on the pump vent line rather than buy new ones.

 

Remove the filter, pull out the foam rubber plug at the inlet, shake out the carbon filters, wash out, refill with new activated carbon pellets and put the foam plug back in.

 

New carbon pellets are very cheap, look for cooker hood filter pellets on Ebay etc.

 

This saves a fortune. I forget what LEESAN used to charge about 30 quid each I think?

[John and Liana Fox]

I cut out most of the top of the plastic carbon filter carefully, clear out old carbon pellets and dry it out, refill from cheap big bag of carbon granules, place the plastic side on top and secure with wide plastic gaffer tape. Works ok.

[jonesthenuke]

1 minute ago, John and Liana Fox said:

I cut out most of the top of the plastic carbon filter carefully, clear out old carbon pellets and dry it out, refill from cheap big bag of carbon granules, place the plastic side on top and secure with wide plastic gaffer tape. Works ok.

You take the side off? Does it not leak?

[John and Liana Fox]

I cut off most of the top big flat side (Leave 7mm around the edge, say), refill and replace it in position , and stick the thick plastic duct tape wound round the whole box so it covers and overlaps the whole Top, so there is no air leakage.  As the smelly air blown through is damp, it is a good chance to dry it out too.

Edited August 12, 2020 by John and Liana Fox

[John and Liana Fox]

13 hours ago, pearley said:

I did have a situation with mine where the pump micro switch was worn so it wouldn't work when the cassette was inserted but would if it was fully pressed by hand. Does it still stop after 15 seconds if you just hold switch in?

 

As you have changed PCB then it looks like a pump problem.

I find it may only work once with the tank fitted, but with tank off,  With tank micro switch pressed, the pump switches on and off fine if you put your finger over the vacuum sensor hole. I have ordered new microswitches in case mine is malfunctioning like yours, when the tank is fitted.

[jonesthenuke]

Just now, John and Liana Fox said:

I find it may only work once with the tank fitted, but with tank off,  With tank micro switch pressed, the pump switches on and off fine if you put your finger over the vacuum sensor hole. I have ordered new microswitches in case mine is malfunctioning like yours, when the tank is fitted.

With worn switches the setpoint changes and they lose there hysteresis (the difference in plunger position between switch on and off). The original switches are relatively cheap items used on washing machines etc and do not last indefinitely. It's easy to change them if doing other work on the loo and is worthwhile in my view to get long term freedom from faults.

 

[jonesthenuke]

I see Leesan have entered the "complete rip off" part of the boat maintenance market. 34 pounds for a switch that can be sourced for 4.32 from RS and 50 quid for the carbon filter. I may have to start selling spares!?

[RivetStreamer]

On 10/08/2020 at 08:21, jonesthenuke said:

Yes thats a typo. I will have to check that one.

Any measurements on the input pipe to cassette base seal dimensions please?

[jonesthenuke]

If you mean where the pipe from the loo pushes into the base unit its 40x6mm (I assume you mean this and not the seal on the spout of the base unit where it plugs into the cassette?)vacuflush toilet spare parts list (dragged).pdfvacuflush toilet spare parts list (dragged).pdfvacuflush toilet spare parts list (dragged).pdfvacuflush toilet spare parts list (dragged).pdf

Edited January 30, 2023 by jonesthenuke

[RivetStreamer]

Great thanks. O rings ordered and also ordering ‘switch recognition cassette’ part. Just hope I can fit it easily enough. 

[pearley]

I've got an unused printed circuit board if anyone wants it, although it may take me a while to find it.

[RivetStreamer]

1 hour ago, pearley said:

I've got an unused printed circuit board if anyone wants it, although it may take me a while to find it.

I’ll nab it as a spare unless anyone’s need is greater. Happy to cover postage of course

[pearley]

1 hour ago, RivetStreamer said:

I’ll nab it as a spare unless anyone’s need is greater. Happy to cover postage of course

Send a message with your address. Won't be immediate though as it's buried under the floor of my wife's wardrobe.

[jonesthenuke]

If changing the O rings etc get some silicone grease. Plenty on Ebay, look for "silicone grease plumbing" that way you will get reasonably sized tubs for about £10 as opposed to small tubes. I put some on the big ball valve at the bottom of the pan every couple to months. It reduces friction and helps with the sealing.

 

 

Edited January 30, 2023 by jonesthenuke
Typo

[RivetStreamer]

2 hours ago, pearley said:

Send a message with your address. Won't be immediate though as it's buried under the floor of my wife's wardrobe.

I’ve just joined this forum as I found this thread after much googling. So I need a few more posts before I can message you. Would you mind sending an email to  talkers-07-mop@icloud.com and I’ll get back to you. Thanks!

Edited January 30, 2023 by RivetStreamer
Contact added

[John Ray]

Hello did you rectify this problem as I have exactly the same issue with mine. The vacuum builds for a short time but after flushing the vacuum has gone. Amber light constant on wall panel. 😢

[blackrose]

I've still got a full set of o-rings for the vacuflush if anyone wants them? Send me a PM

[jonesthenuke]

13 hours ago, John Ray said:

Hello did you rectify this problem as I have exactly the same issue with mine. The vacuum builds for a short time but after flushing the vacuum has gone. Amber light constant on wall panel. 😢

Loss of vacuum could be from a number of things. What have you tried so far? Does the seal in the toilet keep water in the bowel after flushing?

[blackrose]

15 hours ago, John Ray said:

Hello did you rectify this problem as I have exactly the same issue with mine. The vacuum builds for a short time but after flushing the vacuum has gone. Amber light constant on wall panel. 😢

 

After flushing the vacuum should have gone, then the pump kicks in and builds up the vacuum again.  Do you mean it won't hold the vacuum for very long after that? As asked above, is it holding water in the bowl or is it draining? If it's draining you need to clean the ball & seal and possibly replace that seal.

 

You need to check all your o rings and seals including the double o ring inside the spring loaded pipe that goes into the cassette. Remove the cassette and push back the outer part of the pipe to get to it. Clean it with a wet wipe or damp cloth and apply silicone grease all around or you might need to replace the o ring. If it's not that then there's nasty connection where the shit pipe from the toilet enters the back of the cassette docking station. There's a big fat o ring there that also needs silicone grease. That connection can get quite messy. That's why I ended up getting rid of mine. Servicing them is a horrible business.

 

I assume you switch the vacuum pump off if it's not holding a vacuum? If you don't the pump will keep cycling and just wear itself out.

[John Ray]

Hello thanks for your responses.The toilet bowl holds the water fine and when you insert the cassette you can hear the vacuum pump engage but only for a brief time, about 10 seconds. The toilet flushes ok then (albeit not as powerfully as normal) and the contents does flush away. 
 

the vacuum pump does not engage after this and the toilet will no longer flush. In order to get it to work you have to remove the cassette again and then after a short time re engage it and the whole process is repeated. 😵‍💫

Also the amber light is constantly on at the wall monitor. 

[pearley]

Get down on your knees with cassette out and press the bottom right micro switch. Pump should run constantly. The put finger over hole in vacuum tit top centre and press switch again. Pump should run for a few seconds and stop.

3 hours ago, blackrose said:

 

 

 

If it's not that then there's nasty connection where the shit pipe from the toilet enters the back of the cassette docking station. There's a big fat o ring there that also needs silicone grease. That connection can get quite messy. That's why I ended up getting rid of mine. Servicing them is a horrible business.

 

 

As the large pipe on mine went through 90° and was unsupported I made a bracket to stop any unwanted pressure on this seal. Packed with silicone grease and it was the only deal that never gave me trouble.

[Ken X]

6 hours ago, jonesthenuke said:

Loss of vacuum could be from a number of things. What have you tried so far? Does the seal in the toilet keep water in the bowel after flushing?

Many thanks for brightening a rainy morning. 🙂 .  Gotta luv a spearchucker.😄