It does sound like you may need to reduce and restrict his area until litter habits are reestablished. You may need to add in some extra litter boxes. Really, as many as it takes, including filling up his floor space in his restricted area if needed.
[ Tablet users, try the "web" version by clicking on "web" at the bottom of this page for a better, user-friendly format . ]
rabbitsindoors.weebly.com
From your previous thread (sorry I missed your response), couches are tricky things with rabbits. Couches and beds really absorb our scent, more than anywhere else, so some rabbits can't resist adding theirs. And some rabbits can't resist peeing on soft things.
A few things to try. Get your couch professionally cleaned so as much scent is removed (may or may not work). Try putting a blanket up there with your buns scent already all over it. Put a litter box up there. Try catching your bun pre urination and usher directly to the litter box and/or a place for a 'timeout' (you're claiming the couch as yours essentially). Cover the couch with a waterproof cover. Block access, or immediately remove your bun from the couch when he tries to get up there, then sit on and 'claim' that exact spot (how rabbits claim space).
Here's what the experienced bunny moms do to stop this frustrating habbit.
bunnyproof.com
Is your rabbit peeing on the couch all of a sudden? Read on to understand why and find out what you can do to correct this unwanted behavior.
myhouserabbit.com
Lastly, if your bun is peeing in random places, dribbling urine, has thickened urine, blood in the urine, or straining to urinate, this is a likely medical issue and you should immediately get your bun checked by a knowledgeable rabbit vet.
Urinary disorders in rabbits.
wabbitwiki.com
Veterinary emergencies. What to look for, preparing for a visit to an emergency center, and links for rabbits.
wabbitwiki.com
wabbitwiki.com
rabbit.org
