We had one in our caravan ... it worked ok for awhile and then it started to lose the vacuum and it would keep on cycling about every 10mins. I replaced all the O rings, cassette cap and the big seal under the seat. In the end it just wouldn't pump up the vacuum ... the vacuum pump wouldn't stop.

After ringing Dometic and finding out they stopped supplying these about 2 years ago ... and no other replacement loo to be had ... scary. With design of our van we couldn't get an ordinary toilet installed, it had to be vacuum. They did however give me a contact for 'Sea Breeze' a company in Norwell, near Jacob's Well. They have a certain amount of spares for the VT2500, but better still a different brand ... 'Sealand'

We towed the van to them  they installed the new holding tank and pump and it with no fuss and I found the price extremely reasonable. They normally install the units in boats, but starting to install quite a few in RV's, replacing the VT2500. It has been installed and looks and works terrific. It's only a small company, but very professional. If you have a problem with your vt2500, ring Colin Albright and 'Sea Breeze' The best phone I made.

Cheers

Alby