I use vivi novas a great deal, mostly all the time. First possibility is that you are not really getting the wicks free of old flavor and that mix can really give an ugly taste - using vodka or vanilla extract or a mix of both to rise them and letting them air dry over night can fix that.
Depending on the juice you use the coils can get very gunked up and rinsing just won't help - sometimes it makes it worse as it moves some of the gunk down on the connection as well as it being all around the connection.
Its time to replace your head - but to extend the life you can try dry burning the coils and blowing the produced ash away. If the coils are really in bad shape dry burning does of the risk of breaking the (not sure if its called burning them out or not) coiled where they make contact with the battery. In that case you have to replace the head but you were going to have to anyway it seems. I keep a 5 pk of vivi nova heads in my supply box so I can switch out once dry burning them a bit ( not like crazy -just enough short bursts to turn the gunk on the coils to a white ash that can be blown away) no longer extends their lives.
You can just replace the head - they are relatively cheap - no reason to dispose of the rest of the vivi nova - but dry burning will extend the life and any thing that saves a couple of dollars for a couple of weeks is worth it.
Depending on the juice you use the coils can get very gunked up and rinsing just won't help - sometimes it makes it worse as it moves some of the gunk down on the connection as well as it being all around the connection.
Its time to replace your head - but to extend the life you can try dry burning the coils and blowing the produced ash away. If the coils are really in bad shape dry burning does of the risk of breaking the (not sure if its called burning them out or not) coiled where they make contact with the battery. In that case you have to replace the head but you were going to have to anyway it seems. I keep a 5 pk of vivi nova heads in my supply box so I can switch out once dry burning them a bit ( not like crazy -just enough short bursts to turn the gunk on the coils to a white ash that can be blown away) no longer extends their lives.
You can just replace the head - they are relatively cheap - no reason to dispose of the rest of the vivi nova - but dry burning will extend the life and any thing that saves a couple of dollars for a couple of weeks is worth it.