I am seeking information and help, so I am posting this to the most diverse well informed group of people I know.
I installed a geothermal heat pump system when I build my home back in 1988. Not sure how much preliminary information to put here, so this is a short summary. The system has a closed loop water+ propylene glycol source loop. Originally I had a 6 ton water to water heat pump that I purchased used. It quit working after 20 years. I now have two 3 ton units. The heat pumps take heat from the source loop to keep a 50 gallon tank in the basement between 95-100ºf. (in summer this is reversed and the tank is 38-43ºf) Hot water from the tank is then distributed as needed through the radiant heat system in the floor of the house. Each room has its own heating thermostat and floor loop (In summer the cold water is pumped through air handlers for cooling with one thermostat). The two heat pumps are staged so that only one runs unless there is a very high heating or cooling load, then the other one kicks in. I went with two separate units instead of a dual compressor model so if one unit fails, the other one can still function.
Here is the problem. The controller on one of the heat pumps is failing. I am not able to find a replacement. The heat pumps I got are were made by Florida Heat Pump. (WW036-1USC-FXX) They are now out of business. Apparently they were taken over or purchased by Bosch. I contacted Bosch and got no response. Each unit has an ICM controller. (LPR-AM7805, 641-190). I contacted ICM to see if they could provide a replacement. Their response is they made those controllers for FHP and have no replacements and nothing similar.
These heat pumps are not rocket science. They are just a collection of standard components you could get at any good HVAC supply house; Copeland scroll compressor, compressor contactor, reversing valve, heat exchangers, control circuit transformer, a temperature sensor, high and low pressure sensors and the controller.
What I am seeking now is a solution to this problem, either by some other manufacturer or homemade.
Any ideas would be appreciated.
Thanks for your time,