State heat pump water heater keeps running

[Mev]

I have the Sense Monitor and application so I can trace appliance electrical usage. I've searched the titles in this forum, but could not find a match to this problem.
State HPX-66-DHPT installed in basement, lows 60s year round, tank temperature set to 125 degrees, whole house soft water conditioner.
Installed 10/20/2020. Worked perfectly in efficiency mode for almost 2 years. Would run for 1-2 hours per day on average to keep temperature in the tank around 125 degrees. A couple weeks ago I noted that it was running for over 4 hours without a change in water usage (one person living in house). Installer came out on 10/05/2022 and recommended that I switch to the default Hybrid mode which I did. Seemed ok until this morning. I used hot water the afternoon before, but none at night or today. The heat pump has been running now for 6 hours. Drawing around 1.2amps in heat pump mode.
Electric mode works so I have a backup.
Is there anything you can tell me to recommend to the installer to look into? Already paid for one visit.
Thanks,
Mark

 

[Mev]

I called State Water Heater and they were very helpful. Did a couple of tests over a couple of hours, looking at the value of the different temperature sensors. There is a refrigerant issue and I get a free replacement, but I have to pay for labor.
So good and bad.

 

[Sponsor]

 

[WorthFlorida]

If it is determined that the refrigerant is low, that means there is a leak on the low pressure side. Hopefully the tech has a sniffer tool. Hybrid water heater techs need to be air condition technician with a EPA certificate, not a plumber.

 

[Mev]

If it is determined that the refrigerant is low, that means there is a leak on the low pressure side. Hopefully the tech has a sniffer tool. Hybrid water heater techs need to be air condition technician with a EPA certificate, not a plumber.

The State Heater rep was not interested in anyone fixing it, I asked. They just replace. Since I have to pay for labor, it might be cheaper to cut it out and replace instead of the installer chasing the leak down and trying a fix.

 

[WorthFlorida]

I figured that what would happen. Water heating manufacturers are just that, not refrigerator manufacturers. If a refrigerant leak is on the coils around the water tank, they are not possible to get to. Hybrid WH's are nothing but a refrigerator and made without valves to check pressure after manufacture. I think it will be awhile until hybrids can work as reliable as most refrigerators and the need to add sensors to know when the refrigeration side is not working properly, but that just adds cost.

 

[Fitter30]

Looking at the install manual low refrigerant pressure has a failure code nothing else has. Could be simple as a condenser fan motor. Agree plumbers don't usually have epa certification or work on refrigeration enough to keep up with all the changes.

 

[Mev]

I figured that what would happen. Water heating manufacturers are just that, not refrigerator manufacturers. If a refrigerant leak is on the coils around the water tank, they are not possible to get to. Hybrid WH's are nothing but a refrigerator and made without valves to check pressure after manufacture. I think it will be awhile until hybrids can work as reliable as most refrigerators and the need to add sensors to know when the refrigeration side is not working properly, but that just adds cost.

These are the temperature sensors in this unit:
P1 Upper Tank Temperature Measured at outer upper tank wall
P2 Lower Tank Temperature Measured at outer lower tank wall
P3 Coil Temperature Measured at hairpin of evaporator
P4 Discharge Temperature Measured at compressor discharge pipe
P5 Suction Temperature Measured at evaporator outlet pipe
P6 EEV Pulses EEV (Electronic Expansion Valve) opening indication
Are you saying that pressure sensors would also be helpful?

Something about this hybrid water heater is that twice it has jumped out of Electrical mode to Hybrid mode. The first time it happened there was maybe a 10% chance I was remembering wrong about which mode I left it in. But when it happened this weekend again, I'm now positive there is also something flaky in the computerized controller.

 

[WorthFlorida]

Looks like using temperatures can determine refrigerant issues. I just replaced my 15 year old electric water heater with a standard electric for this very reason. Hybrids are great saving energy and even being able to cool down the very hot garage here I Florida. I went standard though hybrids had a $800 rebate was complexities. A standard water heater as only 4 parts that can go bad And anyone can repair it if there are no leaks. 2 heating elements, two thermostat. Fool proof and they've been around forever. I'm 73 and one day if I'm not around and the wife is living alone, a complex WH that can fail multiple ways and very costly shy'ed me away.

 

[Mev]

Well, the original water heater kept jumping back to Efficiency mode out of Electric mode every few days.

Plumber came out and replaced with new on, it has been running about 2 hours a day in heat pump mode (.2-.3KWh/day), so it is working. Only bad thing was the $1100 labor bill to replace. I'll call State and complain, probably won't help other than me feeling better that I complained.
Simple calculations point this heat pump water heater experiment will save me money compared to a same size electric only water heater only if nothing else goes wrong with the heat pump for 7 more years. Won't be holding my breath.

 

[Fitter30]

What is the surrounding temp. Being a heat pump dumping cool air into the space? Is this heater in a basement or utility room?

 

[Mev]

What is the surrounding temp. Being a heat pump dumping cool air into the space? Is this heater in a basement or utility room?

Basement temp around 60.
Utility room, about 16'x16' with an opened door to the rest of the basement, ceiling also open to rest of basement. Inefficient oil boiler right next to it that also heats the utility room during the winter.

 

[Fitter30]

Looks like using temperatures can determine refrigerant issues. I just replaced my 15 year old electric water heater with a standard electric for this very reason. Hybrids are great saving energy and even being able to cool down the very hot garage here I Florida. I went standard though hybrids had a $800 rebate was complexities. A standard water heater as only 4 parts that can go bad And anyone can repair it if there are no leaks. 2 heating elements, two thermostat. Fool proof and they've been around forever. I'm 73 and one day if I'm not around and the wife is living alone, a complex WH that can fail multiple ways and very costly shy'ed me away.

They use temperature because the system hold very little refrigerate just checking pressures if they had a way for access would lose to much in a critical charge unit. Sealed systems in a lab, engineers document dozens of different scenarios to come up with the different temps.