Hybrid Electric Water Heater

I encountered a couple today & just thought I would share with those who may not have experienced them yet.


The bottom ¾ is much like any other unit with 2 heating elements while the top ¼ is a mini heat pump. This heat pump has an air filter on top, an exhaust on the side & a condensate line (white pvc) that drains outside.
The cold water comes into the room, up the wall to an anti-siphon device (required by our local AHJ) then back down to the bottom of the unit where it enters next to the drain port. The water is heated by the 2 elements, kept hot by the heat pump & then exits from the middle of the tank.
The TPR valve is located on the side & plumbed to the outside with cpvc (off white pipe)

Takeaways for inspecting:
Inspect much like any other electric water heater
-elecrical disconnects per usual
-shutoff valve on cold water per usual
-TPR valve & plumbing per usual
-expansion tank required per the usual (missing on these units)
-the higher discharge line is a condensate line, no need for special piping material
-the cold water feeds in from the bottom
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This looks crazy but isn’t really all that different. As far as the condenser, I check that it runs, (usually comes on when I discharge the TPR valve) has filter, air intake & exhaust has proper clearance, condensate drain plumbed correctly.

Happy Inspecting!

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Thanks for sharing, Brandon!..always learning. :smiley: :+1: :upside_down_face:

My pleasure! Hopefully this helps someone the next time they run across one.

Great Information, Thanks!

Wow great breakdown in your post💪

How do you verify the heat pump is actually maintaining the water temperature? other than simply running.

Good question!
I do not & describe both verbally & in my report that hot water is present, however, since there are multiple heat sources & testing resistance on elements and/or voltage on the thermostats is not part of my home inspection service, I cannot verify the operation or efficiency of the heat pump or individual elements.
I started to include that in the original post but felt it was clouding it up.

This is an area of inspection that other than the unit not putting out hot water, leaking, rusted, missing safety valve, etc. , this is an area where unless you are trained in servicing that piece of equipment, you are not certified to inspect it and qualify it. Unlike an HVAC system inspection, a home inspector does not measure amperage draw or check line pressures. If you are also an HVAC tech, then go ahead inspect it, but it should be done outside and in addition to the envelope of the Home Inspection.

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Just a couple of additional notes. With Hybrid water heaters, room volume is very important as is orientation of the exhaust ports. The way the 2 are set up in the pic, they wouldn’t be nearly as efficient as they could be. They pull air in from the top and exhaust the dehumidified cooled air from that port on the right upper of both units. You reduce the efficiencies if they are recirculating the air in a small room, or if the exhaust is blowing against the wall which can lead to condensation problem. These work best when they are in large areas(think unfinished basements or attic space in warm climate zones. I ducted mine to pull outside air in the summer and discharge to the air return on my furnace, so it also provides make up air for the house in my case. Winter time, I can either pull from the den where I have a wood stove that has its own external air supply or from a duct through the attic space. Most of these units can function with intake air down to around 40 degrees F but of course are more efficient if the intake air is over 80 degrees F. These do have an air filter that requires Maintence but its a simple pull, rinse and replace. They are also wifi enabled and Rheem has an app that allows you to control the water temperature, heating mode(heat pump only, HP and elect elements, Elements only and vacation mode), along with telling you the actual power consumption by the hour or day. Average yearly operating cost is only $110 for a 50 gallon unit!!
My only gripe with them is the engineer who designed them picked the worst pipe placement for all the connections. T&P, water inlet/outlet and condensate seem haphazard and difficult to make for a clean install.