Provision is made of a radiant heating pipe 10 which is designed to conduct hot gas through a central portion 14 in a preferred direction of flow SV, directed away from the burner 22, into at least one return portion 16, 18 and preferably at least partially back into the central portion 14, such that a recirculation flow through the radiant heating pipe 10 is produced overall. The smallest flow cross section DA for the gas in a zone 24, close to the burner, of the central portion 14 is smaller than the smallest flow cross section DE in a zone 26 remote from the burner. Preferably, the radiant heating pipe 10 according to the invention has a waist at the transition from a branching portion 13, close to the burner, to the central portion 14.