My open loop water to water geothermal unit seems to be struggling to get up to the thermostat heat temperature setting. I measured the inlet and outlet water temperatures and it is less than a half degree difference. I previously had it dialed in nicely but apparently that has changed. So as I understand it I need to slow down the water discharge to allow longer time for the unit to extract heat from the inlet water, but my question is simultaneously do I need to also increase the amount of water flow into the unit from my well? The Bosch Geo unit is only 4 years old and my water quality always test good.
I would assme what you feed in comes out, so I am not sure that playing with the circulation speed should need to change, since it has been working properly in the past. Not understanding your system properly, it would seem that your heat exchanger is not working. Others here would have better guidance I am sure, but I think that there may need to be more specifics provided. Hopefully its not your only heat source.
If your heat pump is working and extracting heat from the water, then yes, slowing down the water flow will increase the temperature difference in proportion to the flow reduction. However, changing the water flow should not substantially change the amount of heat extracted. So, with only an 0.5 degree delta-t and the system not keeping up, your heat pump isn't working and I'd expect the problem won't be solved by lowering the flow rate.
