[en] Gas recycling has been studied in a large number of tokamaks for several years. On TFR, a previous experiment with an inconel limiter had shown that, after many discharges in hydrogen, when we change the working gas to deuterium the wall adsorbed isotope accounts for less than 5% after a few shots. In order to have a better knowledge of the gas recycling we have done similar experiments with two different limiters -an inconel limiter and a graphite limiter- at room temperature and with hot walls (250⁰C< T<300⁰). With the graphite limiter, when the filling gas is changed from 100% H₂ to 100% D₂, the isotopic ratio H/H+D is between 25 and 30% after five shots and reaches the limit for approximately 12% after ten shots. This ratio decreases more rapidly with hot walls but the lower limit is higher: 10 and 20% with inconel and graphite limiters respectively, instead of 5% and 12% at room temperature. The recycling coefficient is a always higher with hot walls; this consequently should reduce the plasma edge temperature. The sputtering and the thermal load on the wall and the limiters might then also decrease