A search for a heavy resonance decaying to Zγ, with the Z boson further decaying to pairs of electrons or muons is presented. The search strategy is to look for an excess above the non- resonant Standard Model background on the l+l−γ invariant mass spectrum. The search is based on 13 TeV proton-proton collision data collected with the CMS detector, corresponding to the integrated luminosity of 12.9/fb.