Heat Pump H20 Heater - Please Help :(

[adeyo]

unfortunately, no leaflelt found inside the shroud

[NiHaoMike]

How much did you pay for it?

[adeyo]

Originally Posted by NiHaoMike

How much did you pay for it?

$350 ....I was told by management that it only needed heading elements. the guy in charge was a real jerk when I tried to return it saying I bought it as is. tried fighting at corporate level to no avail.

[NiHaoMike]

Good deal if the compressor runs, OK deal if it doesn't. (That assumes the tank is good and not a reject, of which there's a high chance since they bothered to install the compressor.) Worst case is that you have a heat exchanger hot water tank with electric backup (as might be used for solar hot water), along with an evaporator coil assembly.

Assuming the compressor runs, you just have to add back missing parts, change the oil and liquid line drier, pull a vacuum, and charge it up. For the controls, just a thermostat will work, although you can certainly build up a controller with an Arduino if you wanted something better.

[adeyo]

Originally Posted by NiHaoMike

Good deal if the compressor runs, OK deal if it doesn't. (That assumes the tank is good and not a reject, of which there's a high chance since they bothered to install the compressor.) Worst case is that you have a heat exchanger hot water tank with electric backup (as might be used for solar hot water), along with an evaporator coil assembly.

Assuming the compressor runs, you just have to add back missing parts, change the oil and liquid line drier, pull a vacuum, and charge it up. For the controls, just a thermostat will work, although you can certainly build up a controller with an Arduino if you wanted something better.

Thanks! I guess i'll check that pdf for what parts are missing. But, i'm hoping to use parts i can pick up from my local plumbing supply store (and not order replacement parts from GeoSprings which are way to expensive). so, i have a few questions...

1) Without the computer board, how do i supply the electricity needed for the compressor and fan to run the heat pump?

2) Also, how do i supply electricity for the heating elements? do i simply wire them just like a standard hot water heater to a thermostat, which i assume i can set to have it kick on when the water hits a certain degree and then stop when it reaches a certain degree?
(i.e. completely independent of the heat pump? or would i need to somehow make the heat pump a priority and only have the electric kick on after the heat pump attempts to run its course?)

3) Once i have all running properly, (w/ sufficient electricity, charge etc). How do i hook up a thermostat to the heat pump to direct its on/off cycle? do i get parts for a window AC unit or something? or again, a simple thermostat provides power or cuts off power when the water reaches the desired temp?

Thanks for all your help. I know I'm a novice, but once i grasp the concepts and instructions i don't think i'll have a problem getting it all to work. It seems like i don't need to fancy control board, but really just 3 independent systems tied into separate thermostats: heat exchanger, upper heating element & lower heating element. Correct???

IF i am completely lost, please redirect my thinking. Thanks!

Adam

[NiHaoMike]

I suggest just using a regular hot water thermostat, but use it to only operate the compressor. You can ignore the heating elements for now. Keep in mind that the lower you keep the temperature, the higher the efficiency. (That's true of all water heaters, but especially so with heat pumps.)

If the fan motor is ECM (which I remember was the case for a GE), you may need a PSU to run it. Something as simple as a wall wart might work.

[adeyo]

Originally Posted by NiHaoMike

I suggest just using a regular hot water thermostat, but use it to only operate the compressor. You can ignore the heating elements for now. Keep in mind that the lower you keep the temperature, the higher the efficiency. (That's true of all water heaters, but especially so with heat pumps.)

If the fan motor is ECM (which I remember was the case for a GE), you may need a PSU to run it. Something as simple as a wall wart might work.

Ok, here is what the manual has...

1. Fan cycles on/off w/ compressor: fan single speed, 240v (pic attached)
2. Wiring Schematic attached
3. Compressor Schematic attached

[adeyo]

Also, here are a couple of pics showing what i have on my fan/compressor in the way of wires... attached...

1. wires out of fan are brown and grey (it is grey although hard to tell from pic) the grey wire is cut. where should it go? (i think it went to the control board) brown wire goes into the compressor (start capacitor??) Also, notice blue wire coming from compressor is cut (where does it go?)

2. brown wire seen going to compressor (again, start capacitor??)


So, this leaves me with figuring out what to do with these wires in order to run the fan and compressor to test the heat pump portion of the hot water heater. Anyone know the answer?

[jeff5may]

Ok, wiring is no big deal. It looks like your 220v unit runs off the 2 hot lines, no neutral, and ground. As such, both lines going to and from components will be hot, so you have twice the risk of being shocked. 110v stuff always has a neutral wire, which is in theory the same potential as ground. I could be wrong, but be careful. Don't get hurt.

All the components should be labeled as to their respective power requirements. They may or may not run on 220v. Check first, because electricity is one of the most unforgiving forces in the world. Letting magic smoke out of a fresh new component, especially an expensive one, is disheartening to say the least. Make sure you feed the thing what it wants (or less to test).

That being said, the wires you mentioned are all power wires. The compressor has its own integrated start cap, so according to the 3rd pic, the yellow wire will connect to L2 and the blue will go to L1 thru an overload and control relay. The fan motor looks the same way: the brown goes towards L2 and gray towards control and L1. From this general design trend, I am guessing that GE is using L2 as a "hot common" line and exercising control through the connection to L1. In this case, the heater elements would have similar connections. One leg would tie to L2 at the yellow compressor wire and the other leg would be controlled on its journey to meet L1.

The unit looks pretty darn brand new. I don't trust it. Before you go energizing all these components, I would definitely leak check everything. Plug up the tank, pressurize with air to 5-10 psi and let it sit overnight. Same thing with refrigerant loop, although at higher pressure. Come back in the morning and verify nothing leaked down. This testing will most likely make or break the unit, since there is a large part of the tank( and condenser coil) that is not serviceable.

Also, I have questions about the heat pump circuit.

What refrigerant does this unit use? Like Mike said, the newer units have variable speed fans in them and use R410a. This older unit has a constant speed fan, so who knows what gas it uses? The main factor here is the oil. Different gases like different oils, and the newer oils absorb water when exposed to atmosphere. With your unit, an oil change is obvious, especially if it runs off R410a.

The unit has an electronic expansion valve in it. Without a digital control board made for this line of unit, how will you control the valve? This is a science project in college engineering by itself. I honestly don't know what to tell you about that one. Good luck?

[stevehull]

Jeff makes excellent points as they are easy to do.

I doubt the tank has a leak, but this is the simplest thing to check so do it first.

The condenser coil (refrigerant loop) is the killer. If it has a leak, the tank is useless, but you may have a good compressor!

Check those two exactly as Jeff said and get back in touch. All else can be fixed . . .

Steve