If you rent the hot water tank you are responsible for having it delivered back to one of Enbridge's yards for disposal if defective. The break even point for a high efficiency water tank is around 5-7 years depending on the cost. If you install your own (which I did) the only warranty you have is factory warranty. Not sure if the door to door is a fly by nighter or not. Sounds fishy to me.
'05 GMC Sierra SLT Z71 CCSB 4x4
'02 Regal LS
'00 740i Sport