Installing a hot water tank for the bathroom - pressure equalization?

I want to install an open hot water storage tank (non-pressurized) in the bathroom instead of an instantaneous water heater. There are two 1/2 inch water connections in the wall, one for hot, the other for cold, connected to the sink and shower. I want to connect the boiler to these connections. When the water heats up, it expands; how do I handle the pressure compensation? Can I install a low-pressure fitting at the sink and blind one of the three hoses?

Hello

Non-pressurized hot water tanks are usually intended for only one outlet point.

Why not use a pressure-resistant tank?
Connect the leak water pipe, for example, to the drain of the [WT].

Olli

Hello, thank you for the response. I had already used the [druckkosten Boiler] and cannot return it anymore.