This paper presents an experimental investigation of combustion instabilities for a laminar premixed flame stabilized on a slot burner. For certain operating conditions, the system exhibits an unstable mode locked on the Helmholtz mode of the burner. It is shown that the instability can be controlled and even suppressed by changing solely the temperature of the burner rim. A theoretical model accounting for this parameter in the flame transfer function is devised and the physical mechanisms for the temperature dependance of the flame response are investigated.