Tank (TL) and Tank (G-TL) modelling

I have made several attempts to model a group of tanks. Ultimate goal is to model liquid stratification within a tank using Simscape.

Best option I could think of was to use several tanks (either Tank(TL) or Tank(G-TL)) interconnected. The tank(s) are being heated using an external energy source via a liquid circuit. Another liquid circuit is drawing heat from this system for space heating purposes. It all works well, until I attempt to connect either circuit to circulate within one of the tanks. The purpose is to heat up quickly 1st tank, while the liquid is being circulated through all of them via the 2nd liquid circuit.

The liquid circuit shown on the left is circulating through the 1st tank. The liquid circuit shown on the right is drawing fluid from the 1st and discharging in the 3rd tank. When the left circuit is drawing from the 3rd tank, I can run the simulation but cannot get desirable results. The error I receive is the following:

• ['tank_f/Solver Configuration']: Transient initialization at time 697.1347861939707, solving for consistent states and modes, failed to converge.
• Nonlinear solver: failed to converge, residual norm too large.
• Here is the set of components with unconverged equations: 'tank_f/Tank (G-TL)1'Equation location is: 'C:\Program Files\MATLAB\R2018b\toolbox\physmod\fluids\fluids\+fluids\+interfaces\+tanks_accumulators\two_port_gas_two_port_dynamic_liquid.sscp'(no line number info) Equation location is: 'C:\Program Files\MATLAB\R2018b\toolbox\physmod\fluids\fluids\+fluids\+interfaces\+tanks_accumulators\two_port_gas_two_port_dynamic_liquid.sscp'(no line number info) 'tank_f/Tank (G-TL)1'Equation location is: 'C:\Program Files\MATLAB\R2018b\toolbox\physmod\fluids\fluids\+fluids\+interfaces\+tanks_accumulators\two_port_gas_two_port_dynamic_liquid.sscp'(no line number info) Equation location is: 'C:\Program Files\MATLAB\R2018b\toolbox\physmod\fluids\fluids\+fluids\+interfaces\+tanks_accumulators\two_port_gas_two_port_dynamic_liquid.sscp'(no line number info)

Your support would be much appreciated.