Issues are piling up now. My second unit (E060TL101NBDSSA) has the water flow light flashing. What is the cause of this flashing light? This unit is not piped with a DSH. Filter recently washed but I washed it again to be sure, no change. If it's low fluid, how do I check? If not low fluid, what is it?
This is a temperature switch on your incoming water. This indicates either poor water flow and/or low entering water temperatures.
What would be the cause of either? Low water level? Low ground temperature? Too shallow a loop field? What should the ideal range of incoming temperature be?
it is possible that your loop temp has dropped so low that the water leaving your heat pump is freezing. Any idea what kind and how much antifreeze is in the loop?
No idea about the type of liquid in the loop but it smells like sweet alcohol? The loop on that unit is in a very wet area so with this cold and lack of snow, I wouldn't be surprised one bit. That side of the property is also very rocky, bedrock would be fairly shallow too.
On some systems "low water flow" alarm light is set by a low temperature sensor at the refrigerant / water heat exchanger. Low refrigerant charge can fool the sensor and control board into posting the low water flow alarm.
I guess the first thing to do is measure the EWT ( temp of the water coming out of the ground, going into the heat pump). If close to 30°, then check the antifreeze to see how low you are protected.
I believe the subject sensor may be in or on the refrigerant line near where loop water leaves the heat exchanger, so leaving water temperature may offer more insight / diagnostic elimination toward resolving this. Stated another way, if entering water temperature is a relatively healthy 50*F+, but flow has somehow dwindled below 1.5 GPM per ton, leaving water temp may well be nearing the freeze point cutoff (if not freeze protected and trip point reduced from 30 to 15) OTOH if leaving water is well above 30*F (assuming water only, not antifreeze) then look to a loss of refrigerant charge or TXV / metering fault. Mark's two pounds down / need-a-new-airside-coil incident is not uncommon, unfortunately.
