Non-continuum subtracted H₂O spectra for the detection of the west and east and the non-detection at the position at the HzRG and H₂O moment-0 map. Top left panel: H₂O line detected ~50 kpc to the east of the radio core, has a 3.7σ significance. The emission is located due west of the knot A in the radio jet. The fitted Gaussian is over-plotted in orange. Top middle panel: spectrum at the position of the radio core, shows no detection of H₂O emission – only continuum emission. A small separation between the two spectral windows results in the gap in the continuum between − 1300 and − 1500 km s^-1. Top right panel: H₂O line detected ~25 kpc to the west of the radio core, showing a 4σ H₂O detection at the expected frequency for z = 2.161. The emission is located at the bend of the radio jet, B4 (Pentericci et al. 1997). The best-fit Gaussian is over-plotted in orange. Bottom panel: moment-0 map of the H₂O emission (without continuum subtraction), overlaid with the 246 GHz continuum emission in green contours. The orange ellipses show the H₂O emission and the orange-red diamonds the positions of the knots in the radio jet, given by Pentericci et al. (1997).