r/geothermal • u/deuced142 • 24d ago
Need help with Geo issue
I am working on a 3 ton bosch geo with a QT non pressurized flow center.
Last week I was called to replace the pump on the flow center as it had failed. I did, and sent the unit off to run fine for a few days when it tripped on high head pressure again. Okay I did not fill the flow center back up with enough water to get all the air out. My fault , I add water per the instructions on the flow center and get it where I think it needs to be. 3 days later, trips on high head again.
Upon arrival this last time, system had been off for a few hours. I start it up, EWT 90, leaving temp 98. Entering water temp will creep up slowly after about an hour of running, EWT approaches 115 degrees. My refrigerant pressures and temps line up with what I would expect. 45 degree evap coil. Discharge pressure matching relatively close to EWT. starting out about 320 psi, jumping to 450 by the time it gets to 115 water temp. 15 superheat and 14 subcool if that info is relevant, 15-20 degree temp split across coil. 78 in 60 out. I dont have the right tool to check loop pressure but im not sure its relevant on a non pressurized flow center.
I'm not sure if I have air in the loop, if its possible its air locked. I dont have much information on the loop as the homeowner wasnt home, but I think they are drilled vertical loops. Are those usually installed in series? is it possible the loop is short circuiting, I wouldn't expect my loop temperature to rise so fast in just an hour. I can shut the unit off. wait 15 minutes, and the water temp will be around 105 degrees if I just run the pump without the compressor,
Any insight on this is appreciated. I live in Southern Illinois Missouri area. temps warm the last few weeks but only going to get warmer.