initial condition to boiler modelisation

hello all,

i try to modelise a boiler with simscape. on the moment, i have this code

component chaudiere

% chaudiere

% Ce bloc modélise le fonctionnement d'une chaudière.

nodes
    A = foundation.thermal.thermal; % A:left
    B = foundation.thermal.thermal; % B:right
end

variables
    T = { 0, 'K' };
end

parameters
    Pch = { 0, 'W' }; % puissance de la chaudiere
    Cp = { 4.1868, 'J/kg/K' }; % Cp eau
    Debit = { 0, 'kg/s' }; % debit d'eau
end

function setup
if Pch < 0
    error ('P chaudiere doit etre plus grande que 0');
end
    if Cp < 0
    error ('Cp eau doit etre plus grand que 0');
    end
    if Debit < 0
    error ('Debit doit etre plus grand que 0');
    end

     across( T, B.T, A.T ); 
     % température variable de L à R

end

equations
    B.T==A.T+Pch/(Cp*Debit);
end
end

but the solver can't solve it because there is too much variables.

so i want to put an initial condition for A.T (the input temperature) bu only for the first iteration. after, input temperature will depend of an another output.

How can i do this?

thanks for your responses.