Hi, I recently bought a house and it has geothermal heating. They said its the most efficient you can get....BUT i dont think it is. My house is 100% electric so the bill in the summer with the system off is around $150. In the winter, the unit runs almost all the time when its cold, and my energy bill is in the $400-$500 range. This cant be the "efficient" normal. Question is, where do i start looking or troubleshooting the system? I dont have a trusted geothermal tech close. Thanks
Figure out if the compressor is actually running. And figure out if you have backup (electric) heat running. Start there.
If your backup heat strips are turning on a lot, that will significantly affect your electric usage as they will require approximately 3 to 4 times as much electricity as the heat pump for the same amount of BTU output. Your heat strips are controlled by your thermostat. Do you keep the thermostat constant or do you raise and lower the temperature night vs. day? If you lower the temperature at night too much, then raising the temp too much it in the morning can cause the heat strips to automatically kick in. Your thermostat may also be adjustable to allow setting the differential temperature higher where the heat strips kick in which will reduce their run time. A low differential setting can cause the heat strips to turn on sooner which can improve comfort but cost you more in electricity usage. What make and model heat pump do you have and what make and model thermostat do you have? Does your system have multiple zones?
Arkie is right on. Don't make the system jump too high or it will use the quick, but expensive energy. I have two units; in the main house, I leave the temperature constant and it purrs along just fine. My mother-in-law suite was a different story. MIL insisted on cooler temps at night. It took me a thermostat upgrade and program tweaking to get it right. Now heat stays 71 daily, drop to 67 at 7 pm to coast down for bed-time. Ramp to 68 @ 5 am, 69 @ 6 am, 70 @ 7 am, 71 at 8 am. Works great. Generally stays in stage 1, bumps to stage 2 as needed, and rarely uses electric heat.
This reply is a year after the thread ended - so this for newer lookers: My system did exactly the same 2019- ran too long and aux or emergency heat often kicked in. High cost is related to the heat strips heating the home. On reversing HP for summer, constant run with register temps at 78 + degrees and house not cooling. I checked the HP and the compressor was running and Reversing valve could be heard moving if I changed cool to heat. Non-geo HVAC came - found low freon level. Added and the HP was cured with register temp readings at 57 or less degrees. Not everything is a Geo HP type fault - sometimes its an HVAC system thing. The system doesn't appear to be losing capacity so either its very very slow freon leak or was a maintenance overdue item. Start simple.
Had the same experience - unit needed aux. heat to meet set temp and ran too much. Reversing for summer cool, the unit ran constantly and register temp at high 70s. HVAC found low freon also. Added gas immediately fixed the problem. Winter, the heat strip came on late in the evening and took a while to catch the aux light function on. As above - no noticeable loss of function after the freon recharge. Air at the register mid 50s - waiting for winter to monitor between this vs last year kW usage.
