  B-Physics anomalies have recently raised renewed interest in leptoquarks
(LQ), predicted in several theoretical frameworks. Under simplifying but
conservative assumptions, we show that the current limits from LHC searches
together with the requirement to explain the observed value for $R_{D^{(*)}}$
constrain the $R_2$ leptoquark mass to be in the range of $800 \leq m_{R_2}
\leq 1000$ GeV. We study the search for $R_2$ at the LHeC via its resonance in
the $b\tau$ final state by performing a cut-and-count analysis of the signal
and the dominant Standard Model backgrounds. We find that the LHeC has an
excellent discovery potential for $R_2$ even for couplings to the first
generation as small as ${\cal O}(10^{-2})$.
