I just bought a house near st louis, MO (my first house ) it has Geo thermal and was built in 1987, i found paper work that the compressor unit was replace in 2004. its a mammoth 4.5 ton unit. I has 2 pumps in push/pull config. I was told there are 3 wells that are 320 feet each. the house is about 2500-2800 square feet. in July when it was 100+ every day the unit was one and would shut off for 5 minutes and turn back on. I learned the 5 minutes is built in to stop compressor damage so it was really running all the time. The power bill is $525 the loops are warm, the hottest day when it 108 outside the loop coming out of the unit i could not hold with my hand the return loop from the ground i Could. (115/105) temps with my IR thermometer. I don't know what maintenance needs done to these and if it has been done. what do i need to do (other then filter changes witch i buy Merv 13 filter for it because of my allergies) I do know i need insulation in the attic (only 4 inches ) also it uses an old mercury thermostat, i want to replace wit ha digital one that is preferably Z-waze compatable as i plan to install z-wave in the house. (2 stage heat and one stage cooling)
dunno Z wave, but can tell you most of the thermostat offerings of "smart" house products are very unsophisticated. Not quite sure what to make about a potential service problem. Nor do I have any base line to determine if that electric bill is out of line. I would need to know what is interupting the system- high pressure, low pressure, poor staging etc. First thing I'd probably do is jump the thermostat to rule that out.
Bill seems high for a house that size. I see no good stopping the system for 5 minutes - that's the last thing one wants to do to a compressor, stop and start it for no good reason outside normal temperature control of the home. Entering water temp above 100 sounds like a problem - system could be a bit underlooped, coupled with extraordinarily hot weather. Or, one of the loops may be air-locked - no water flowing so it is not participating, overloading the others. I'd also want to know why a house that size needs 4.5 tons of capacity...come to think of it, that's a strange size...are you sure of that figure? Is there anything that can be done to reduce cooling load - film some windows, fix some airleaks, augment attic insulation? Has anyone checked for duct leaks? If ducts are in unconditioned space, that could be huge. I'd say you need a competent energy audit followed by a competent tech to figure out why your loop fluid is so hot.
