I am not familiar with the regulation of Bosch heat pumps, but a few things caught my eye at first glance that have nothing to do with your problem right now, but are not acceptable like this:
- Installation position of the domestic hot water circulation pump is wrong, it won’t last long like this
- Shut-off between drinking water safety valve and storage tank is not permitted (if it is closed and the heat pump heats the storage tank, it can burst)
- Installation position of the drinking water safety valve lying down is not allowed, the discharge pipe is also missing. If the expansion vessel (why anyone still installs such a germ incubator nowadays) is broken, the water will flood your technical room
- Thermal insulation is completely missing
- Whether the Cosmo standing tank is suitable for heat pumps at all due to the small heat exchanger surface should be clarified with a phone call to Bosch Service, I can’t imagine it
- If I see it correctly, the domestic hot water circulation line is connected with a T-piece at the hot water outlet. I lack the imagination of how the pump is supposed to draw the hot water from the storage tank.
If the rest of the system looks the same.