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:
- 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!
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:
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