Hello again knowledgeable geo fiends, I last left you all in early 2013 debugging a zone issue with my new WaterFurnace 7 Series (3 Ton) unit and verifying the Manual J calculations done by the original installer. Summer with our new home/system was delightful, with electric bill more or less right in line with my simulations for the house. However now that we are back into winter, and a particularly cold winter here in central Maryland I have been getting a regular error, frequently coupled with a lockout. "ERROR E5: Freeze Detect FP1". What strikes me as a little strange is that I have seen the error both when the system is running hard and when it isn't (has happened in all compressor stages 1-8, I have yet to witness anything higher), and is inconsistently coupled with the lockout. I have found that by restarting the thermostat, and thereby giving the system the standard 5 minute power cycle countdown timer the error frequently clears. Sometimes it is back in under an hour, but usually this will keep it at bay for several (6+) hours. Thanks to a contact made here on the GeoExchange forums I have a shiny AID tool to get all the nitty gritty details about the system, but will put them in a separate post to keep things a bit more organized. Thanks in advance for any insight into the problem. Michael
System details: WaterFurnace 7 Series 3 Ton Horizontal loop: Two 225' trenches with two 3/4" pipes in each trench out and back. Total 1800' of 3/4" pipe. IntelliZone2 System with a total of 3 zones for the house AID Details: These are from a random error, taken shortly after it entered the error condition (within 5-10 mins). I probably have (or can get) more detail, but am including just what seems relevant for now. Status: Normal Mode: Heating Faults: E5 Frze Detect FP1 IZ2 Comp Spd Des: 5 Comp Spd Act: 5 IZ2 Blower % Des: 70% Blower Spd Act: 7 FP1: 33 F FP2: 80 F Ent Water: 32.6 F Lvg Water: 29.2 F WaterFlow: 7.8 GPM Brine: Antifreeze Ht of Ext: 12826 BTU Loop Press: NA PSI Ent Air: 72.9 F Lvg Air: 81.7 F Discharge: 255 PSI, 129.8 F Suction: 88 PSI, 35.4 F Htg LL: 82.6 F Clg LL: 33.2 F Sat Evap: 25.2 F Sat Cond: 85.1 F EEV SH/Open%: 10 / 66% SubCooling: -2 F CompAmbient: 74.0 F VS Drv EWT: 32.4 F
Your unit is set to open loop vs. closed loop, so it is doing as it should. Change the FP setting to closed loop.
Be sure loop fluid is properly freeze-protected. The closed loop setting lowers the trip point to 15*F, if I correctly recall.
"Hello again knowledgeable geo fiends......" Freudian slip perhaps? As Curt said, make sure you are freeze protected.
Mike: I'm a EE in southern maryland... I'd like to pick up an AID tool too... what's the approx cost?
They are only a couple/few hundred dollars. I am not sure if end users can purchase them? I am sure your dealer will sell one to you. Also, rumor has it Nov. 1 that you will be able to see all the AID tool settings with the online portal that will be out soon.
