Rheem Proterra Heat Pump Water Heater exchanger iceing up
Hi,
Our Rheem Proterra 60 gallon heat pump water heater has been installed for a year and run flawlessly until now. The HPWH is installed in an open basement space with input air coming from our heated basement at around 19 deg C. Output air is ducted to the outside. Current outside air temp is about 10 deg C. We live in Vancouver, Canada.
I’ve been running the HPWH in Heat Pump Only mode throughout the year. In the past few days I’m now seeing considerable frosting up of the exchanger and continuous running of the compressor after just one shower. Almost the entire input face of the exchanger is covered in frost which grows thicker towards the bottom. I finally switched to the Rheem EnergySaver mode to give the compressor a break. Why is this now happening and what would be the source of the problem? Or is this normal and I just need to let it run until it’s ready to shut off?
Many thanks, Gary
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Replies
One of your thermistors is quitting. Common and an easy fix. The onboard diagnostic will show you which one is bad and Rheem will send you a new one (or a few) for free. Google Rheem thermistor replacement and dive in.
Thanks for the pointer to thermistors. That appears to be the problem. After finding out how to check on the different thermistor temperatures, it seems like one or two are malfunctioning.
Water heater set temp is 49 deg C.
Four thermistor temps:
discharge: 191 deg F
ambient: 77 deg F
suction: 64 deg F
evaporator: 81 deg F
I assume there is some appropriate relationship between these temps that controls the compressor.
Hope to have replacement thermistors in the next few days, in the mean time I'm running mostly in electric mode.