FWT and HWT Question

[Murph60]

I drain the water tank, by the drain knob next to the tire. Do I need to do anything with the red and blue pipe with the white caps that are closer to the front of the TT?

Also, how do you know when the fresh water tank or hot water tank are nearing empty. Is there another way other when no water comes out of the faucet? I would think that would be more of an issue with the hot water tank so you don't fry the heater.

Thanks

[PapaGlenn]

Originally Posted by Murph60

Also, how do you know when the fresh water tank or hot water tank are nearing empty.

We have a 15 gallon tote tank for GW. When it’s full, we know we’ve got 5 gallons left and it’s time to think about filling FW.

[NavyLCDR]

The red and blue pipes with the white caps are low point drains for the hot water and cold water side of the plumbing system. You should only open those when you are going to winterize.

You drain the fresh water tank through the fresh water tank drain that you are currently using. You can watch the level on the fresh water tank on your monitoring panel. It's empty when water stops coming out of the drain.

To drain the hot water tank, you need to remove the plug in the bottom of the tank located on the outside behind the panel covering the water heater. The plug will probably have the anode rod attached to it so be prepared for the weight of the anode rod when you remove it. That is the only real way to drain the hot water tank. Make sure the hot water side is depressurized before removing the plug by opening a hot water faucet. You want the controls for the electric and gas side of the water heater turned off before draining. And also you don't want to be messing with the drain plug until after the hot water has cooled.

If I remember correctly the drain plug/anode rod takes a 1 1/16" socket. You'll probably want a short extension and a breaker bar, the plugs can be tight. I used an impact wrench to loosen mine the first time. They don't have to be gorilla tight when you re-install. Use a couple wraps of teflon tape on the threads to reinstall, and moderately tight so there is no leakage, just like any other pipe-thread joint.

[Murph60]

Originally Posted by NavyLCDR

The red and blue pipes with the white caps are low point drains for the hot water and cold water side of the plumbing system. You should only open those when you are going to winterize.

You drain the fresh water tank through the fresh water tank drain that you are currently using. You can watch the level on the fresh water tank on your monitoring panel. It's empty when water stops coming out of the drain.

To drain the hot water tank, you need to remove the plug in the bottom of the tank located on the outside behind the panel covering the water heater. The plug will probably have the anode rod attached to it so be prepared for the weight of the anode rod when you remove it. That is the only real way to drain the hot water tank. Make sure the hot water side is depressurized before removing the plug by opening a hot water faucet. You want the controls for the electric and gas side of the water heater turned off before draining. And also you don't want to be messing with the drain plug until after the hot water has cooled.

If I remember correctly the drain plug/anode rod takes a 1 1/16" socket. You'll probably want a short extension and a breaker bar, the plugs can be tight. I used an impact wrench to loosen mine the first time. They don't have to be gorilla tight when you re-install. Use a couple wraps of teflon tape on the threads to reinstall, and moderately tight so there is no leakage, just like any other pipe-thread joint.

Thanks. Since I don't have a monitoring panel on this Aframe, I guess I just have to keep an eye on the tank. Can you harm anything by just waiting till your faucets are dry?

Thanks

[NavyLCDR]

Originally Posted by Murph60

Thanks. Since I don't have a monitoring panel on this Aframe, I guess I just have to keep an eye on the tank. Can you harm anything by just waiting till your faucets are dry?

Thanks

What exactly is the goal you are trying to accomplish?

[Murph60]

Originally Posted by NavyLCDR

What exactly is the goal you are trying to accomplish?

My first intent on this post was confirm what valve controls the FWT drain when I am done camping. That has been answered.

My follow up question was do I run the risk of damaging anything if I run the tank dry during normal use while camping and whether I need to monitor the water level before the faucets run dry. If I let the faucets run dry and the hot water heater is still on, don't I run the risk of frying the heater?

[OYO]

Originally Posted by Murph60

My first intent on this post was confirm what valve controls the FWT drain when I am done camping. That has been answered.

My follow up question was do I run the risk of damaging anything if I run the tank dry during normal use while camping and whether I need to monitor the water level before the faucets run dry. If I let the faucets run dry and the hot water heater is still on, don't I run the risk of frying the heater?

I think I answered the HW question in your other thread. Short answer is no.

If your FW tank went dry you could/would burn up the pump. But it's going to start making a racket once the tank gets low. If you're running water you're gonna be in the camper. It would be hard to miss the pump noise.

[NavyLCDR]

Originally Posted by Murph60

My first intent on this post was confirm what valve controls the FWT drain when I am done camping. That has been answered.

My follow up question was do I run the risk of damaging anything if I run the tank dry during normal use while camping and whether I need to monitor the water level before the faucets run dry. If I let the faucets run dry and the hot water heater is still on, don't I run the risk of frying the heater?

I'm sorry, I misunderstood the second part of your question. RV water pumps are diaphragm type pumps. They will not be damaged by running them dry. The pump will actually be quieter when the FW runs out, the pump will run faster, but quieter. That being said, there is no need to run the water pump with the FW tank dry, so as soon as either the pump runs fast and won't shut off, or you get air out of your faucets, you should turn the pump off until you refill the FW tank. Then it will take a little bit of pumping air with the fresh water pump (with a faucet open) in order for it to prime itself.

The water heater should not be damaged by pumping the fresh water tank dry either. There is a check valve in the bottom (cold water inlet) of the water heater that will keep water from flowing from the tank back into the cold water side. The hot water outlet is at the top of the tank. So, if you should pump your freshwater tank dry, and open a hot water faucet, air will get pumped into the bottom of the tank and it will rise through the water and be expelled through the hot water outlet. There should be enough water that stays in the tank to keep it from being damage if the heating source is left on.

Again, though, this should not be a normal practice. As soon as you know you are running out of water in the fresh water tank you should turn off the water pump and turn off all sources of heat to the water heater. But, if you don't and things run for a while with the fresh water tank dry, nothing should be damaged.

[Murph60]

Thanks Navy. That makes sense.

[NavyLCDR]

Go ahead and try it intentionally so you know what happens. When I want to drain my fresh water tank, I intentionally pump it dry with the built-in water pump. I normally pump the water into black tank flush connection (through the outside shower hose) just prior to going to the dump station to dump tanks. I turn off the water heater before doing so, though. There will be residual water in the fresh water tank, so if you want to get all the water out, you still need to open the tank drain.

Of course, I have to watch the black tank level and stop pumping into it when it lights the full light on the monitor panel.