I installed my new hot water heater and hot water heat pump this weekend.  Works perfectly (Almost)! I decided to purchase an 80 gallon Whirlpool lifetime tank and a heat pump unit from Air Generate. Together the total cost was about $1100. $600 for he water heater and $500 for the heat pump. Since my old unit was not in the best shape I could deduct the cost of the tank, but I switched from gas to electric and you can buy smaller gas water heaters because the recovery time is usually better. I figured on about $400 dollars for a new gas tank. That would make the upgrade cost about $700.

Installation was a trip to say the least. Actually, the biggest problem was removing the hot water nipple from the new tank. The nipple only extends maybe a half inch from the top of the tank. In the end I had to buy a huge 16″ channel locking pliers, set the tank on the floor and use my weight to finally get it to come off. The nipple was destroyed but I was not needing to use it again anyway. That fiasco took over three hours.


After the nipple was removed the remainder of the process was very straight forward. The instructions do a good job explaining everything. Air Generate also has an installation video on their website. After everything was done I only had one leak. It was from the fitting that passes the thermostat wire outside the tank. I just added some Teflon tape and tightened it down. No more leak.

Some time ago I purchased an extra Kill-a-watt. Now I can see exactly how much electricity this unit uses! With that,  I filled the heater full and bleed out all the air. The heat pump ran for a little over 6 hours and used 3.33kWhrs of electricity. The temperature was set to 115 degrees. I just looked at the Kill-a-watt and it now reads 12 kWhrs over 72 hours. That would be 4kWhrs a day. But, I also raised the temp setting to 125 degrees. The main reason for raising the temperature is because the tank is so big and the current thermostat has a 15 degree on/off hysteresis. My I take a shower cold water enters the bottom of the tank. Then ,when the wife jumped in an hour later the tank temperature would even out to around 100 degrees. She did not like taking a shower at 100 degrees. So I had to turn it up.

The current thermostat is only 26″ long and the new one will be 38″ long. This will allow it to extend further down the tank. Thus after a shower the unit should turn on. Also, the new thermostat will have a on/off hysteresis of only 10 degrees. After I install the new thermostat I will go back down to 115 degrees. This should bring the electricity usage back down. (I found out about the new thermostat after I called about the leaking fitting. They are sending today. Customer service was very good and helpful. On the phone and Email!)

One more important thing to note. I DID NOT PLUG IN THE WATER HEATER! That is correct. This is just a storage tank. The tank has a lifetime warrenty. So hopefully, I never need to mess with another tank again.