Note: This post is for reference for residents of my neighborhood community. It might also be helpful for anyone who has electric water heaters with solar water heater assist.
Many of us now have brand new shiny, not yet iron-choked water heaters. While I give Frank Sayne of Just Water Heaters high marks for efficiency in his installation skills, he was rather brief on the tutorial front of how to use the new product. When asked, he and his co-worker did explain everything they could to me, but they were pressed for time to change so many tanks. I do believe he did a good job but we can certainly maintain them better than we have in the past.
Allow me to tread these warm waters for you. Also, if you haven't joined the water heater swapping party, I (and the rest of the Structure and Maintenance Committee) greatly encourage you to consider replacing your tank if you haven't done so in the last 8 years. Most of us had waited 16 years and they were well past due.
For evidence, I took a picture of the old tanks after they had been removed. See the evidence for yourself!
The first thing you should know is that we have a different system than most other homes. We have electric dual element water heaters with a supplemental solar water heater (SWH) that feeds into it. In order to constantly blend the hot water coming from the SWH to the tank, we have recirculation pumps installed on the pipe that uses electricity to pump water in and out of the tank throughout the day. Your recirculation pump is likely brown and has the brand name Taco on it. It also has a black chord hanging out of it going to a yellowed plastic box mounted to your wall. On the front of this wall mounted box is a plate you can remove with a flat head screwdriver. Behind that cover is are two adjustors. One is for the frequency or time of day the pump will operate. Mine is currently set to 12. Other options are 6, 18, and 24. You simply swivel the red dial to change this setting. The other red knob is for the thermostat on the recirculation pump. My pump has always been warm but after they put in my new tank, my pump was unbearable to touch - something like 150 degrees. That seemed to be not right. Frank had already left so when he came back the next day to work on other homes I asked him to come look at it. He did and agreed it was too hot. His specialty is replacing tanks he does not specialize in unusual systems nor does he cater to trouble shoot issues with parts he doesn't normally deal with. Rather than remove my pump and disassemble it for inspection, he suggested we just replace it, which he did. The new one was also very hot, but I suggested we adjust the thermostat on the pump and when I did that, it instantly cooled off.
Something important to note about electric water heaters is that they have two thermostats. One up high and one down low on the tank. This is because there are two heating elements to keep the water evenly heated. Gas water heaters don't need this because the flame at the bottom is strong enough to heat the entire tank (I'm guessing here) but electric tanks need these two elements. Our recirculation pumps also have their own thermostat so that's three thermostats total. Here's the important thing,
You need to have all three thermostats adjusted to the same temperature or you risk burning out one of the elements because it will be working harder than the other two. To access the tank's thermostats, first turn off the power to the water heater by turning off the breaker switch on the circuit breaker panel in your downstairs hallway. Then, take a flat head screwdriver and remove the two screws of the upper cover plate on the side of your water heater. You'll see two foam insulation pieces like this.. Pull those out and you'll see something like the second picture.
In the center of that opening, you'll see a small bolt that looks like a screw. This is the thermostat. There is a guide next to it. If you want to change the temperature of your water, use your flat head screwdriver to adjust this thermostat to the desired temperature. Deciding exactly what is the proper temperature is up for some debate.
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| Recirculation Pump Control Box with Thermostat inside. |
The manual that came with the water heater says that homes with small children should not have water hotter than 120 degrees. It even suggests considering adjusting your water temperature less than that to avoid any chance of scalding. Certainly by having water warmer than 130 you will increase your risk of injury and use unnecessary energy to keep that water very hot. I have read online however that water heater tanks need to keep the water in the tank at a minimum of 130 degrees to prevent bacteria from growing in the tank and not doing this can potentially lead to Legionnaires Disease and other health problems. From what I've read, if your tank is set to 130 degrees, then the water will actually cool off about 10 degrees as it makes its way in the pipes to the nearest tap, and that water will then be a safe 120 degrees when it finally touches you.
The EPA says your tank should be set at 120 degrees but OSHA says it should be at 140 degrees. It really comes down to how susceptible are you to illness? If you're not extremely susceptible, you can likely do fine with 120 degrees.
The manufacturer preset my tank to 125 degrees and I chose to leave it there. However, my recirculation pump was at 140 degrees and likely led to it being so hot. We also noticed that my original pump was not making any noise, possibly indicating that it had ceased to function. After Frank changed my pump, we heard the new one working and after I adjusted the temperature on that, it cooled down right away. Bottom line, adjust all three thermostats to the same temperature and periodically check the temperature of your Taco pump to make sure that it isn't too hot.
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| Thermostat and timer for pump (red knobs). |
The manual also recommends periodic maintenance of the tank by occasionally bleeding off some of the water from the pressure relief valve. This is an "emergency door" for the hot water in the tank. In the event of an emergency of too much pressure, the tank is designed to send the excess pressurized water out the pressure relief valve. It's like when your car radiator cap finally pops open, that keeps the radiator from cracking. I believe the discharge for this pressure relief valve is on the side of our homes, where it would come out one of the random plastic pipes we have sticking out of our walls. Forewarning, if you do lift this pressure relief valve, and that is recommended once per month, make sure that no one is standing near or under the discharge pipe as hot water will come out of it. I believe you simply lift the silver tab to release water out the discharge pipe. You don't need to do it for very long, just a short burst to ensure that water can flow out if needed.
Then there's the flushing of the tank. Just to make you feel better, let's pretend that, like you,I've never done that before. Here's how, as explained by Roberto and Frank. At the bottom of your tank, you'll see a pipe with threads that looks like a garden spigot with no handle. I think this should actually have a cap on it but they forgot to put mine back on. I will ask them for it again. At least every six months, connect a garden hose to this threaded pipe. Drag the other end of your garden house down the staircase and into the downstairs shower or tub where it can send the water down the tub drain. Use your flat head screwdriver to turn the tiny handle (screw) only 1/4 turn to open the valve. The water heater does not need to be turned off to do this. Only leave the valve open for 15 seconds. Then close it and wait two minutes. The tank will be refilling itself and the 2 minutes will allow more particulates to settle to the bottom of the tank. Then open the valve again for only 15 seconds. Then close it and wait 2 minutes. Do this a total of three times and then you should be good. 
When done flushing the tank, make sure the valve is closed (1/4 turn) and then disconnect the garden hose. It's best to coil the hose from the attic, lifting it as you go downstairs as this will force the water in the hose to drain properly into the tub.
Finally, for additional energy savings, you can purchase pipe insulation at Ace Hardware, like the picture above, to better insulate the hot water pipe and prevent some of the heat from escaping.
Another important piece to our system is the expansion tank. This is the metal round water bottle sticking up from your tank or possibly on the side of it. Inside is a rubber balloon that expands and contracts to give the water a place to go when there's a sudden change in temperature or pressure. If you hear your pipes going, "thunk" loudly when you shut the water off at a tap, that could indicate that your expansion tank is not functioning properly and you should have it looked at.
I think we have gotten good units this time around. I think the installation was much better than the first time. I believe Frank knows his stuff and with a little more awareness on our own part, I don't think we should have to worry much about these units until it's time to replace them in about 8 years.
One final thought on the issue of hot water in our community. I know there have been many lessons learned since we first broke ground. Hindsight is always 20/20 but looking back at our experience with hot water, I would caution future developments against the system we used. Solar water heaters don't seem to be able to tolerate the hard water we have in this region. The boxes are too heavy to deal with on our tricky roofs and having the boxes up there required us to have the water heaters in the attics. Though there's not much point in reviewing something that can't be fixed now, it makes me wonder what projects we will take on in the future and how we can learn from one experience to continue to guide our wisdom in another, despite uncertain technology and improved design.
