Wheater made two appearances in the non-first class Pro ARCH Trophy in March 2008 against the United Arab Emirates, and made his first-class debut for Essex against Cambridge UCCE the following month.
Wheater spent the first few seasons of his professional career at Essex as understudy to James Foster. Coincidentally, Foster and Wheater were both born in the same town, Whipps Cross.
Wheater spent the winter of 2010–2011 playing for Zimbabwean franchise Matabeleland Tuskers. He made his maiden first class century for the Tuskers during his spell. On his return, he was picked as a specialist batsman twice in CB40 games for Essex with Foster in the same team. Wheater fielded at slip or point while Foster being the more senior and superior gloveman, kept wicket.