Egro - pump life enters into the decision loop. More winter than summer, so its all good when the HP cools at an efficient cost. The problem is you can't turn it off in the 100 degree summer days - just reduce its intrusion into the home. For anyone wondering about the effectiveness of passive solar - if the sun shines, I've had it heat the home to mid 80s in zero degree temps. Home is passive solar and loss of HP function in 100+ summer heat or loss of heat in freezing winter temps a concern. My heat exchanger is now leaking, I tried contacting the company who installed it but they no longer service geothermal units, ( the tech who worked on them left the company). Would deeply appreciate your input - do you see any issues or impact on older HP or loop on changing out the 26-99 single speed with a variable speed pump? Does the pump itself determine pumping speed demands or would that come from the HP unit? If from the HP, how would I determine the HP ability to monitor/regulate AND would the VS pump need to be wired differently to the HP? 5 Post Likes Command Aire Geothermal Heat Pump I have a command aire geothermal heat pump model GSSD03010F00010C. A bit worrisome in making decisions regarding changes to original configuration. But the age of the HP and manner of loop, headers - not manifolds, confuses the younger geo-techs from the nearest HVAC company. I live in a small town of less than 7 thousand that has no Geo HP HVAC trained techs - after 31 years, original installer retired.
