Heat Pump Air Conditioner/Water Heater

Ahhh, thanks to both of you for answering this question, I have always wondered where you buy them, now I realize the most expensive part of all this is the "snap tie" wedge that holds it flush against the plywood using wood blocks. I've never seen it done, just the results after the completed job, I need a source of cheap wedges so I can give it a try.

Rancher

 

I noticed the rust when I moved it, I have only had it sitting there a month or two

I wish I had taken the time to get a stand alone unit and a separate tank, I was in a hurry to get moved in so I called Home Depot and had this delivered. My first disappointment with it was when it kicked on the resistance elements even though it was in heat pump mode. I called Rheem and they said the resistance elements would run until the temp reached 70F (or 80 I can't remember) and there was not way to bypass it. I found some 129 ohm elements that would draw less power but it added $100+ to my already expensive unit. Next disappointment came when Rheem refused to tell me the communication protocol of the communication port on the front. I wanted to send the unit a message and tell it to reduce the water temperature when my batteries were low and increase the temperature when they were at full charge. I'm sure I can crack the protocol but it will take a lot of time and I may have to buy the WiFi interface so I can send it messages through their app then intercept them. I have been tempted to gut the electronics out of it and just hook it up to a regular water heater thermostat. Right now I have a 30 amp relay that I will use to kick it on and off as needed with the charge controller aux interface.

I really wish I had bought a 24vdc compressor off eBay and just built one myself.

I am going to hook another water heater to it without power just to store the hot water it makes, it will have the same effect as adding more batteries to our system. I may also wire the resistance elements in the second water heater in series with these to increase the ohms and lower the power draw of the elements just in case it ever kicks them on again. I am hoping I can mount the 2nd heater higher than the first and thermosiphon water into the second tank otherwise I will setup a circulation pump.

 

On a sunny day my batteries are charged by 10 am and the panels are putting out 1600w by noon. On a cloudy day, that is a different story, it seems to do okay but I have been watching it like a hawk. I just put up a windmill to try to compensate on days with bad weather.

Our house is partially underground and sealed up tight so dehumidification is a must. 400w for hot water + dehumidification + cooling + air circulation is acceptable for me.

 

Ben, you are absolutely correct, what may be good for me in AZ won't work in the humid South, or the cold North. But we still want to hear how you did things so we can copy them and learn from your mistakes/successes. Thanks!

Rancher

 

Just put the smallest resistance elements you can find in there.
The smallest I have found that were 240v were 1500w.
You can probably get some 480v elements that will use even less power on 240v power.

 

NAW , just ask a former to lend them , or rent .
They come in (the Ties ) 4, 6 ,8.10,,.9.5 for foam structures , after 10" , then the system changes in thickness .
My dad build a construction company , so I was taugh this

 

I added a pump to pump hot water outside through a coil of pipe then back into the water heater. It runs for 6 minutes every hour and pretty much keeps the water heater pumping out cold air all day. I still need to put a plug nearby, mount the pump and make it a bit more professional looking.

 

I found some 480v 2000w elements that draw about 500w at 240v. I think they are 130 ohm.

 

500w is pretty good for our situation.
Where did you get those at?

 

100109772 - AO Smith 100109772 - Incoloy Nickel Base Premium Screw-In Element, 480V 2000W

 

This thing stopped working last night after 1 year of use. I think it is probably the control board, I am debating wiring the compressor directly to an old school water heater thermostat or replacing the board. I am going to take it apart tonight.

 

That's how mine works.
It wires into the existing hot water heater thermostat. Instead of powering a heating element it powers the heat pump.
No fancy gold plated junk (an old air force term).

 

I got the pump to kick on, I think it has a valve that controls the refrigerant flow and I am afraid to run it until I figure out how that works.

 

I disconnected one of the (500w) elements from the relay on the control board and wired it to be on all the time. It is already wired through a thermostat on the unit for safety. The entire unit is setup to come on when our batteries are charged so hopefully it will start making some hot water today the old fashion way.

I found the part number (RCBD-0016011501-01) that I need to replace but a quick search on the web turned up empty.

 

Perhaps the RCBM number on the stick-on tag? The number silkscreened on boards is usually pretty generic...may be used for a dozen different applications.

 

I finally talked to someone at Rheem and they are sending me a new board.