  We present the analysis of XMM-Newton European Photon Imaging Camera (EPIC)
observations of the nova shell IPHASX J210204.7$+$471015. We detect X-ray
emission from the progenitor binary star with properties that resemble those of
underluminous intermediate polars such as DQ Her: an X-ray-emitting plasma with
temperature of $T_\mathrm{X}=(6.4\pm3.1)\times10^{6}$ K, a non-thermal X-ray
component, and an estimated X-ray luminosity of $L_\mathrm{X}=10^{30}$ erg
s$^{-1}$. Time series analyses unveil the presence of two periods, the dominant
with a period of $2.9\pm0.2$ hr, which might be attributed to the spin of the
white dwarf, and a secondary of $4.5\pm0.6$ hr that is in line with the orbital
period of the binary system derived from optical observations. We do not detect
extended X-ray emission as in other nova shells probably due to its relatively
old age (130-170 yr) or to its asymmetric disrupted morphology which is
suggestive of explosion scenarios different to the symmetric ones assumed in
available numerical simulations of nova explosions.
