What i she sequence when backwashing---Backwash - Rinse - Wash ? I have a Vari Flo

if you have a sand filter or de filter turn system off then turn multiport to back wash turn back on let run until the backwash glass is clear turn off then turn to rinse turn back on for about 20 sec then turn off then turn multiport back to filter then turn back on

Does it filter? Does the pump have full prime? I'm not clear about how when the valve is put in the backwash position nothing happens.

Reference your pressure gauge as the 12:00 position. Going clockwise-
12:00 is Filter, normal running position
2:00 is Waste, water goes from pool and exits the waste line, bypassing filter.
4:00 is Closed, used only when servicing equipment
6:00 is Backwash, reverses water through the filter and goes out the waste line.
8:00 is Recirculate, water bypasses filter and returns to pool.
10:00 is Rinse, water goes through filter and exits to waste line, used briefly after backwashing to clear sediment from filter.
Note that the "pointer," not the handle that you grab, indicates which setting you are on.

IF your filter is really the EC75 that's listed in the heading, then it's not a sand filter, its a DE filter. See link to manual:
http://www.haywardnet.com/products/Manuals/pdfs/Manual257.pdf
If this is not the correct number, then you can find the correct manual on their web site. So did it have a multi-port valve already? or did you install it. IF it is a sand filter then there is something plugged inside the filter (small fingers on spider?) If that's the case locate the manual on their web site and follow the assembly insturcitons.

The sand is clogged and needs a backwash or change.

SHUT OFF PUMP TAKE HANDEL AND MOVE TO DIFFERENT POSITIONS TO SEE IF THERE IS CHANGE THERE IS A WHEEL UMDER HANDLE THAT MAY BE OUT OF POSITION TRY A COUPLE OF ROTATIONS START PUMP AND THERE SHOULD BE A CHANGE NEVER TRY TO MOVE HANDLE WITH PUMP ON

it is not seated all the way try turnig to different positions several times if this does not work it probably sprocket wheel under handle assembly is bad or unseated make sure pump is off when changing positions

Do you have a 'Earth' (dirt) filter system.

If - yes - these get block v-quickly (v-quickly!)
* Try to minamize 'vac'ing your pool, (or clean filter each time after 'vac'ing Or Vac on waste setting)
* Use pool skimmer box filter socks.

Check to make sure the plumbing is in the correct inlet/outlet on the valve head. Sounds like it's plumbed backwards. Inlet is from the pump, out to pool...