I frequent the Dish Network forum at SatelliteGuys. I have read MANY times there that all you need to do is call and have Dish put the DHHP on your account (Dish Home H? Protection), It's about $6/month. Then after you get your warranty receiver, you can cancel it. Here's the first thread from a search for DHHP and it, too, mentions that you can call to put on the protection and initiate the service call at the same time.
Monthly Service Plan-Worth the $6?
I realize this sounds bizarre for a company to let you buy warranty service when you already need it, but (as I said) I've seen it posted too many times.
I have DHHP on my account (ever since my first receiver with a harddrive) and don't bother to remove it after I use it, but I could. There's no charge (usually) for shipping.
I did just have a $15 service call ($95 if you don't have DHHP) because I was having difficulty aiming a dish I bought for my RV. I could get the 119 satellite easy enough but couldn't get the second sat (110). I called on a Saturday morning and the tech was there before 3 in the afternoon (and I live WAY out in the country). With his fancy meter (I own a cheap one) he showed me the error in my aim.
[on edit] reading through the thread I linked to, it seems Dish charges $25 for you to stop DHHP now. I haven't been keeping up on the DHHP threads since it's something I didn't intend on stopping. And THAT mainly because I figured if I stopped it, and then needed a new receiver, I'd hear "...sorry, the rules have changed".
There were posts in that thread about receivers being replaced for free + $15 shipping so I don't know if that'd apply to your 722.
[after reading more] it's DHPP -- Dish Home Protection Plan
Phil