Hot Water Heat Pump Hybrid

The Hot Water Heat Pump Hybrid basically consists of a “heat pump” combined with a hot water tank. The one I’m familiar with is the A.O. Smith Signature model 900, 50gal Tall (HPS10-50H45DV). This one has the heat pump mounted on the top. It does contain a standard type Hot Water tank under it which is complete with the two standard electric element heaters and wired to 240v. If you are replacing a standard tank, there are no “AC service” modifications required.
I currently have about 6 years of historical data on running the standard 50 gal tank that was a RHEEM. My hot water usage runs about $30 a month, as measured. The rate per KWh includes all infrastructure and delivery charges. = 16 cents per Kwh.
$30/.16 = 187 KWh per month : Power Usage on the old RHEEM
We have measured several other A.O. Smith similar models and found usage to be in the $5 a month category, which translates to 31.25 KWh per month, about 1/6 the RHEEM. This is significant!

In your sense information, how does your Hot Water heater rank? My RHEEM was like 40% of my monthly electric consumption. It was the number 1, THE HOG!

The HWHPH (Hot Water Heat Pump Hybrid) actually has multiple run modes. In Hybrid mode, It will operate the Heat Pump first, if there is a significant draw down from the hot water tank, the Hot Water element heaters kick on to catch up. So basically, you have the heater elements ready as a backup when you need it. This mode operates like your original HW heater. The difference is that much lower sustaining power is used to keep your Hot Water at the temperature you usually have set.
Here is the added benefit, and additional cost savings. Most people have a “Dehumidifier” in their basement to dry up the unwanted moisture. Well, unplug your Dehumidifier and add that monthly electric cost to your savings. The Dehumidifier is the heat pump! It’s built in. You actually get both a hot water heater and a dehumidifier.
Pretty hot, huh? Wow!
:wink:

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What my 40 gallon rheem used over 2023 according to sense:

and according to the rheem econet app itself:

So don’t expect Sense to reliably detect the electricity usage of the hybrid water heater.

Sense: 283 kWh
The unit itself: 930 kWh

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Interesting capture and comparison.
Rheem app recorded 930 Kwh and Sense app recorded 276 KWh.

Were you able to determine if the element burn time was combined in the Rheem app as compared to the Sense maybe just sensing the Heat Pump usage?

I am in southern Cali so coldest temp winter temperature is about 20F/-8C.
I have it set to heat pump only mode so I don’t think that it ever used the healting elements.
I once had an error condition with regards to the compressor part and when I looked with sense I saw a 4500 watt heating element active.
After power cycling the Rheem the error went away and never returned [knock wood]
So may 30 minutes of heating element usage in the multiple years I have used it.

I’m experiencing the same thing with my Rheem and Sense. Sense is logging a fraction of the usage.

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Hi Adam PM me if you want me to discuss this or have me look more into it. If you want you can share some points of the discussion with me after I just want to make sure I don’t expose any personal info.

Thanks.

James,
My new heat pump HW has not been detected by Sense.
I installed it over a month ago. Can you look into this issue?
A. O. Smith Signature model 900, 50gal Tall (HPS10-50H45DV)

thanks,
-tony

My Rheem HPWH in HP only mode was detected by Sense, but took a while. Give it more time, eventually it will detect it.

Hi Tony,
I very much apologize for the delay in response:

Heat Pumps and Heat Pump HW can be tricky to detect due to the kind of signal data they produce.
If you want me to look further into this issue, I would suggest writing a support ticket and requesting to talk to me directly.
You can do that here: https://help.sense.com/hc/en-us/requests/new

The best way to monitor your heat pump HW is to use DCM. I know this is an extra cost, but it’s the best, most direct way to monitor your heat pump / Hot Water Heat Pumps.

@JamesDrewAtSense, what is DCM?

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Dedicated Circuit Monitor that Sense has.
I understand, if you have an unused solar port, that is a DCM to monitor a single device. Check with James… I haven’t configured one.
-tony

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Ok. I have solar CTs occupying that port. Maybe one of these days Sense will have a multiport unit like Emporia

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