diff --git a/CHANGELOG.md b/CHANGELOG.md
index f9c492050e..66030fb2f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@
 
 ## Bug fixes
 
+-   Add missing separator thermal parameters for the Ecker parameter set ([#1226](https://github.com/pybamm-team/PyBaMM/pull/1226))
 -   Raise error if saving to matlab with variable names that matlab can't read, and give option of providing alternative variable names ([#1206](https://github.com/pybamm-team/PyBaMM/pull/1206))
 -   Raise error if the boundary condition at the origin in a spherical domain is other than no-flux ([#1175](https://github.com/pybamm-team/PyBaMM/pull/1175))
 -   Fix boundary conditions at r = 0 for Creating Models notebooks ([#1173](https://github.com/pybamm-team/PyBaMM/pull/1173))
diff --git a/pybamm/input/parameters/lithium-ion/separators/separator_Ecker2015/parameters.csv b/pybamm/input/parameters/lithium-ion/separators/separator_Ecker2015/parameters.csv
index b1f6cf21a9..d51a852b4d 100644
--- a/pybamm/input/parameters/lithium-ion/separators/separator_Ecker2015/parameters.csv
+++ b/pybamm/input/parameters/lithium-ion/separators/separator_Ecker2015/parameters.csv
@@ -4,3 +4,6 @@ Name [units],Value,Reference,Notes
 Separator porosity,0.508,,
 Separator Bruggeman coefficient (electrolyte),1.9804586773134942, Solve for permeability factor B=0.304=eps^b,
 Separator Bruggeman coefficient (electrode),0,No Bruggeman correction to solid conductivity,
+Separator density [kg.m-3],397,default,
+Separator specific heat capacity [J.kg-1.K-1],700,default,
+Separator thermal conductivity [W.m-1.K-1],0.16,default,
\ No newline at end of file