Epson Wf-3540 w/ Ciss prints blank pages

I love the idea of CISS but have nothing but pains from them, currently the $400 I put towards a printer and CISS set printed beautifully for 3 months then after a random head clean decided to print perfectly blank pages.
I managed to get black back temporarily then again after a head clean to restore the other colors they all vanished.
I have the CISS on the same level as the printer and the airplugs open, I printed every two days and tried to do everything instructed all to no avail. I've now purchased a $25 cleaning solution off ebay that has brought no joy either. Incidentally the CISS is from MIR AUS , now I'm contemplating buying the Wf-3520 that would be compatible with the CISS as one last throw of the dice.....maybe I'm just a glutton for punishment as this is the second CISS system that has not performed as I'd hoped - and destroyed the printer.

Wait a minute: the only difference between the WF-3520 and 3540 is the extra sheet feeder and duplex printing. The upper printing and scanner system is actually the same. Now could you check wether or not the tubing is somehow jammed by the scanner lid, causing ink flowing to a halt somewhere. Why not use 2 sets of refillable cartridges and a resetter?

Thats the reason I'm getting the WF-3520 as it would at least be compatible with my CISS which is sitting with almost full tanks and will be binned otherwise. I kept the printer lid open just to ensure there were no jams, I've tried the original cartridges back in the printer and they print blank as well so the heads are gone. Tried soaking the heads overnight with some wf3540 ink cleaning solution with the same result.
The refillable cartridges might be an idea - however I've already spent so much on the CISS and was hoping it would do the job, the mfr's website indicated air plugs haven't been removed or the tanks need to be balanced , but they were sent full unless I pour ink out this isn't possible so both air compartment and ink compartment is full , with the airplugs open.

Well I bought the WF-3520 , if there are any CISS experts here and have tips on not ruining the second printer please let me know.
Cheers