knight39
Posts: 2
Joined: Wed Jul 06, 2016 7:17 am
Delivery Date: 06 Jul 2016

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

Wed Jul 06, 2016 8:23 am

Hello everybody, the only Nissan I ever owned was a 1975 280Z. I turned 70 yesterday and just wanted to share some old man wisdom. Bringing up the temperatures on the Geospring to figure superheat is kind of tricky. It is easier to look at the evaporator to "see" what's going on. If the lower tubes are becoming frosted and the higher tubes are dry, your unit is low on freon. If the tubes are sweating, but not all the way up, you are probably leaking some freon and the unit could use a charge. My Geospring seems to like about 40 psi on the low side after the compressor has been running for thirty minutes. At that point, all the tubes on both sides of the evaporator are sweating and the output air is very cold. Check the evaporator now and then to look for these tell tale signs.

Regards, Larry

User avatar
RegGuheert
Posts: 6419
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

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

Wed Jul 06, 2016 9:45 am

Thanks for the tips, Larry! I'll look at those things next time I have the cover off.

BTW, the last time I recharged, I used the R139A with leak stopper and lubricant. I'm thinking perhaps I should just go with pure R139A with no additives next time to avoid adding too much oil. What do you recommend?
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

knight39
Posts: 2
Joined: Wed Jul 06, 2016 7:17 am
Delivery Date: 06 Jul 2016

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

Wed Jul 06, 2016 11:31 am

Hello RegGuheert, I have traveled the same road with "leak stopper" and it helped. The oil situation is more difficult to monitor. I have read where oil can become acidic and harm the compressor. There are those who do not recommend "leak stopper" for the same reason.
http://hvac-talk.com/vbb/showthread.php ... l-test-kit Some interesting reading. Also -
https://www.google.com/search?q=hvac+oi ... 8&oe=utf-8 Everything in moderation, right? You meant to refer to R134a, correct?
Google "oil test kit in refrigeration" for more info. I am also going to use straight R134a and test the condition of my oil.

Regards, Larry

Trbodon21
Posts: 1
Joined: Wed May 29, 2019 6:06 am
Delivery Date: 29 May 2019

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

Wed May 29, 2019 6:22 am

I know this post is old, just wanted to say the this has been the most informative location for info regarding this HPWH. I've been struggling to come up with a realistic solution to repair due to labor costs. GE sent me parts for free since I'm under warranty, but estimates for work came in around $500-$700.
Failure code F-C was displayed. Unit is 8 years old installed 2011.
I had about 5 psig of refrigerant in system. My T3a temp was about 10 F with T3b around 65 F.

I followed instructions with line tap valve and had some issues getting the unit to charge. Was very slow and only able to get the pressure to about 35 psig. T3a is now about 45 F with T3b about 70 F. No frost on coils and condensation up about 1/3 of the way, but I'm thinking something is still wrong since the charge was very slow and I can't get a full charge.

Regardless unit is working much better, so thanks for info!

Return to “Off-Topic”