Definitely ask questions about the pond loop.
What is expected flow rate (it is in the installation manual) versus actual. They should measure head of the pump(s) and read the flow rate from the pump chart.
Is the pump sized correctly?
What is the temperature in the pond?
What is the temperature of inlet coolant from pond loop after the heat pump starts running? It shouldn't drop by much. Large drop of the temperature is a sign of poorly performing pond loop.
What is the return temperature of the coolant downstream of the HP. Too large differential between inlet and return is a sign of low flow rate.
What is the pressure in the pond loop?
Is it large enough to prevent pump cavitations?
Was all air reliably purged?
Assuming that the loop is filled with propyleneglycol based coolant what is the freeze protection in the HP set to? If it is set incorrectly (in example for open loop) the protection might lock up the heat pump.
Call another geo installer or technical support of the manufacturer of your system and ask about expected temperature differentials, pond loop pressure, flow rates etc.
Knowledge is power. Don't let them BS you.




Last edited by Ladia; 03/04/09 06:54 AM.
We live in a barn (aircraft hanger) converted to a house.
0.7 ac leaky pond.