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RegGuheert
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How to recharge your heat-pump water heater (HPWH)

Tue Jun 16, 2015 11:22 am

I'm a big fan of the GE GeoSpring Heat Pump Water Heater which I purchased and installed in October 2012. This single unit performs the function of a normal electric water heater PLUS a dehumidifier, yet it consumes about 1/4 of the combined electricity of the other two and it *cools* the room rather than heating it. This unit keeps the basement cool and dry in our humid climate during the hot spring, summer and fall months.

It might seem that such a unit would be a problem in the cold months of winter, but in our application it provides benefits even then. That is because we located our HPWH in an 1100 sq-ft room together with the air handler for our home space-heating heat pump. The result is the heat-pump water heater takes the waste heat from the air handler and puts it into the water, thus turning what used to be the warmest area of the house in the wintertime into the coolest. Since we store a large amount of produce from our gardens in this same room, that is a big plus for us!

Overall, the payback time for a HPWH is about two years when run from the grid. It even compares very favorably against solar water heating when you add in the ~$3000 needed to provide the grid-tied PV required to power it. The cost for a self-install is slightly lower for the HPWH-based solution ($4000 versus $5500) and the product provides 100% of our hot water versus a smaller fraction (~80%) for the solar solution. Hopefully the product life will be better, as well.

But reliability is the reason for this post. Like many early adopters of GE's first-generation HPWH, my HPWH reported a heat pump failure after only two years of operation. While I was not overly surprised by the result based on product reviews I had read, I was still very disappointed.

Fortunately (or so I thought), the unit came with a 10-year warranty on parts, but labor was only covered for one year. So I called the appliance dealer who sold me the unit (along with most of our other appliances). They have an excellent service operation. But they said they do not service the HPWHs they sell. So then I called GE. They, too, said that in my region they do not service the HPWHs that they manufacture. Instead, they have a third-party company which services their appliances. So I called that company, which could not comprehend the conflation of "heat pump" with "water heater". In the end, I decided that paying $99 to roll a truck here with someone who likely cannot spell HVAC was not a good plan. (Are you listening, GE?)

So, here I was with a heat-pump water heater which had likely fully repaid its purchase price, and could function as a normal electric water heater for a long time to come. But that would triple my electricity consumption for water heating. I could replace it and pass on this unit to someone who wanted a normal water heater, but that seemed like a bit wate of money and resources.

I started researching. After a while I found a great resource at WaterHeaterTimer.org which included this link to a complete service presentation on my unit. That presentation told me a few important details about how to proceed:

- This water heater uses the same refrigerant as all of my automobiles: R134A
- The unit could be charged from the process stub connected to the pressure vessel which contains the motor and compressor.
- GE didn't see fit to include a charging port on the unit, even though they did a poor job sealing the units and refuse to service them. (I'm not happy about any of that!)

The presentation says to simply solder on a port to that process stub to recharge it. Really? :?: :?: :?: You mean, pump out all the refrigerant, open the system, cut the stub, solder on a port and then pump it all down and recharge it? O.K. But that will cost a few hundred dollars for the equipment and parts.

So I started searching for the port and I found a MUCH better solution! Here is EVERYTHING you need to recharge a HPWH:

Image

- Line Tap Valve - $5.69
- Air Conditioner Conversion Adapter Kit - $8.61
- R134A Recharge Kit - $32.31
- #2 Philips screwdriver (You're on your own for this one! ;) )

Total: ~$50.00

Here are the steps to recharge your HWPH:

- Turn off the water heater.
- Turn off the circuit breaker to the water heater.
- Use the screwdriver to remove the four screws securing the front panel and remove. (Leave the filter in place to keep the rear cover from falling off.)
- Find the process stub on the right side of the unit. Carefully straighten the 1/8" portion of the stub sufficiently to install the Line Tap Valve. Be sure that you can orient the valve in a way that it can be accessed by the connector on the R134A Recharge Kit. Be sure to not bend the process stub more than absolutely necessary to avoid cracking it and creating a much bigger problem!
- Follow the instructions for installing the Line Tap Valve and clamp it onto the 1/8" portion of the process stub, being sure to orient the unit for access and so that the cover can be replaced. DO NOT PIERCE THE LINE AT THIS TIME.
- Tighten the proper Air Conditioner Adapter onto the Line Tap Valve.
- Fit check the front cover and the R134A Recharge Kit to ensure that they both fit properly before proceeding. Make adjustments as necessary.
- Turn on the circuit breaker.
- Turn on the water heater.
- Ensure the heat pump is running. (Run some hot water if it is not.)
- Read the temperature at sensor T5. The detailed service presentation tells how you can do that. Use this temperature to set the pressure dial on your R134A Recharge Kit for the proper range.
- Without first connecting to the can of refrigerant, connect the R134A Recharge Kit cable to the adapter you have just installed.
- Following the instructions for the Line Tap Valve, pierce the line and then back out the piercing pin ONE TURN ONLY.
- Without pulling the trigger, read the pressure on the R134A Recharge Kit meter. If it is too low, you need to add refrigerant. (Mine read 5 psi when it should have read 45 psi.)
- If you need to recharge, then screw the can of refrigerant onto the R134A Recharge Kit and follow the instructions to add refrigerant until the pressure reading is in the proper range. (For reference, I only added one 12-oz can of R134A to restore the unit to the proper pressure.)
- When you are done, check the readings of the temperature sensors to ensure proper operation of the heat pump. In particular check T3a, T3b and T5. You can find those in the detailed service presentation. It gives some information about the relationships between these temperatures. For instance, the difference between T3b and T3a is the superheat value and should be between 7 and 18 Fahrenheit.
- If all is well, then disconnect the R134A Recharge Kit.
- Screw the cap onto the Air Conditioner Adapter.
- Following the instructions for the Line Tap Valve, carefully screw the piercing pin back in to seal the unit until the next recharge.
- Replace the front cover and install the four screws to secure it.
- Enjoy your like-new HPWH!

Here is a picture of my unit with the Line Tap Valve and Air Conditioner Adapter installed, ready for the front cover to be replaced:

Image

So far it has worked like new since the recharge (perhaps even better, since I bought a display model which may have lost some refrigerant before I even installed it)!

Some of you may have the newer GE GeoSpring Heat Pump Water Heater. I don't know if it has the same problem with refrigeration leakage that the original units had, but I imagine similar procedures can be used to recharge it. For reference, the service manual for the newer unit is here.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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keydiver
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Jun 16, 2015 12:43 pm

This one the main reason why I decided against a heat pump type water heater for my parents house I built two years ago, too many stories of early failures. Unfortunately, I went with a regular old, wasteful electric water heater, and I'm waiting for the technology to mature a bit, or some manufacturer to build one of better quality.
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dhanson865
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Jun 16, 2015 1:18 pm

I bought mine before you, maybe 2010? (I'm at work and the records are at home). It failed for me within the first 2 years but unlike your case when I called they sent someone out with parts and replaced the failed components. He did mention that the first gen units lost their coolant more than they should and that the newer parts didn't have the same issue. I was outside of the first year after installation but they did it anyway.

End result I didn't pay for my service visit, so if you read this thread make the call and check before you do the labor yourself.
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dhanson865
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Jun 16, 2015 1:29 pm

keydiver wrote:This one the main reason why I decided against a heat pump type water heater for my parents house I built two years ago, too many stories of early failures. Unfortunately, I went with a regular old, wasteful electric water heater, and I'm waiting for the technology to mature a bit, or some manufacturer to build one of better quality.


They are already up to the third generation design. Unfortunately they build them overseas and the QC isn't up to par.

I'm not sure if they'll ever get it to 100% reliability but I don't regret getting mine.
Blue 2012 Leaf 195/65/15 tires, 15" Rims
Silver 2012 Leaf 16" stock wheels
wiki/index.php?title=Real_World_Battery_Capacity_Loss
(efficiency 3.x KW vs 6.x KW)
please join Truedelta.com and input your repairs.

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RegGuheert
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Jun 16, 2015 2:17 pm

keydiver wrote:This one the main reason why I decided against a heat pump type water heater for my parents house I built two years ago, too many stories of early failures. Unfortunately, I went with a regular old, wasteful electric water heater, and I'm waiting for the technology to mature a bit, or some manufacturer to build one of better quality.
Understandable. Still, I scolded my sister today for replacing hers with a normal water heater recently. Their basement is somewhat "dank" and they run a dehumidifier nearby. What a waste!
dhanson865 wrote:I bought mine before you, maybe 2010? (I'm at work and the records are at home). It failed for me within the first 2 years but unlike your case when I called they sent someone out with parts and replaced the failed components. He did mention that the first gen units lost their coolant more than they should and that the newer parts didn't have the same issue. I was outside of the first year after installation but they did it anyway.
What I don't understand is why they leak. GE makes outstanding refrigerators with sealed systems that last for DECADES. Granted this is a heat pump which includes a thermal expansion valve to provide superheat, but I don't see where the additional leakage would come from.

Your repair is about two years old now. I'd be interested to hear how things are holding up. Would you mind following the procedure starting on page 92 of the service presentation and record what you read for the following sensors while the compressor is running?

T2, T3a, T3b, T4 and T5

You can use that information to compare against the data on page 82 to see if it is still functioning properly.
dhanson865 wrote:End result I didn't pay for my service visit, so if you read this thread make the call and check before you do the labor yourself.
That's good you didn't have to pay, and good advice!
dhanson865 wrote:They are already up to the third generation design. Unfortunately they build them overseas and the QC isn't up to par.

I'm not sure if they'll ever get it to 100% reliability but I don't regret getting mine.
One reason I wanted to hold onto this one is that often the first-generation units are built like a tank. I don't mind adding refrigerant every year or so, but I'm a bit frustrated the service was so non-existent AND there is no port provided for recharging.

At the end of the day, I have to believe that these heat-pump water heaters should hold their charge for a decade or more. How they can lose half of their coolant in two years is beyond me. Perhaps it leaks out around threads for the black sensor with the blue wire that you can see in the picture.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

dhanson865
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Jun 16, 2015 6:18 pm

My wife is in the shower, unit is running in eHeat mode

T2 116.4F
T3a 36.3F
T3b 81.1F
T4 163.0F
T5 81.2F

Unit was installed in 2010 June so the repair has to be over 3 years ago.

I read most of the PDF service manual then went back to check again, shower ended while I was reading.

T2 112.8F
T3a 37.3F
T3b 80.2F
T4 164.0F
T5 80.3F

and I checked the error code status screen is all zeros.
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RegGuheert
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Re: How to recharge your heat-pump water heater (HPWH)

Wed Jun 17, 2015 4:03 am

dhanson865 wrote:T2 112.8F
T3a 37.3F
T3b 80.2F
T4 164.0F
T5 80.3F
Those numbers are VERY CLOSE to what I would see before I recharged my unit. I think you will need a recharge soon. Note that T3b - T3a = 42.9F. According to page 82 of the service presentation, this difference should be between 7F and 18F.

Also, at 80.3F ambient temperature (T5), T3a should be somewhere around 57F. Yours is about 20F lower than that.

Here is a set of temperatures from my water heater this morning (after my wife's shower :D):

T2 110.5F
T3a 52.8F
T3b 67.6F
T4 150.2F
T5 71.2F
dhanson865 wrote:...and I checked the error code status screen is all zeros.
All zeros does not mean there have been no faults. It means that you have more cases when it does not fault than it does. This is because a successful run (without T3a staying below 20F for more than 30 minutes) will *reduce* the count of faults by 1.

The good news is that it is quite easy to recharge the unit. You might want to go ahead and do that, since it runs much longer when the charge is low, making the efficiency much lower.

One thing I forgot to mention in the OP: It takes less than one hour to do this recharge the first time. Probably will take less than 30 minutes on subsequent recharges.

BTW, I hope your wife had a nice shower! ;)
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

jongig
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Nov 10, 2015 6:32 am

I have searched all over the web and this is the best information yet on my first generation Geospring which was installed 11/2009. I had mine break 4 years ago and they replaced parts plus added a port for charging the refrigerant. I complained enough that they paid for the service as well.

My settings for hot water are 125f and on eHeat only.
My readings for temperature from the sensors are as follows:
T2 - 120.9f
T3a - 31.4f
T3b - 63.6f
T4 - 182.1f
T5 - 71.6f
No fault codes.

My unit is running most of the time and so I decided I'd better look into why. I also noticed that the condenser is ice at the bottom and nearly room temperature in the middle which suggests to me that there is not much heat/cold exchange. Also the fans run constantly on high which is very noisy.

My questions to you are as follows.
1. You used refrigerant from a auto parts store and are they the same since I thought that the refrigerant in cars has lubricant in it?
2. How do you know when the unit has enough refrigerant without complicated test gauges?

My thoughts are that maybe I'd consider buying a new generation one since they're now made here in the US. Lowes has it for $999 and I can get a $400 rebate from our electric company. The unit I have is still under parts warranty but I doubt that any parts are bad except obviously there is a minor leak somewhere. probably from the shrader valves. There is no obvious leak this time like there was last time it broke. On the other hand I think this unit will work properly again with the right amount of refrigerant but calling a technician will probably cost me $300 or more and I'm not sure I should pay this when a new one is $660 ($60-tax).

Thanks for the very well put together post.

John

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TomT
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Nov 10, 2015 9:17 am

Actually, they used to... Modern G.E. refrigerators have poor reliability records (look at CR)...

RegGuheert wrote: GE makes outstanding refrigerators with sealed systems that last for DECADES.
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RegGuheert
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Re: How to recharge your heat-pump water heater (HPWH)

Tue Nov 10, 2015 12:52 pm

jongig wrote:My questions to you are as follows.
1. You used refrigerant from a auto parts store and are they the same since I thought that the refrigerant in cars has lubricant in it?
That is what is specified on page 78 of the service manual I linked in the OP. Yes, it contains lubricant, which is required for proper operation.
jongig wrote:2. How do you know when the unit has enough refrigerant without complicated test gauges?
The compressor must be running in order to recharge it. So I watched the temperatures T3a and T3b to see that they came down into the range specified (10 degrees difference between them). For me, that turned out to be a single can of the refrigerant shown in the OP.
jongig wrote:Thanks for the very well put together post.

You're welcome! I'm glad it was useful to you!
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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