Proper way to drain domestic water system?

rapscallion

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The water in my newly purchased used boat's domestic water tank is old. I need to drain the tank and refill it with fresh water. Opening sink valves will cause the pressure pump to want to re-pressurize the system. What's the best way to drain the tank without running the pressure pump dry? Or is it okay to run the pump dry? Will the pump need to be primed after refilling the tank? Will water gravity feed from the tank to the pump to prime it, or is there some other special way to prime it?

The boat's domestic water system does not include a tank tender or other monitoring system to tell me how much water is in the tank.

1982 Carver 3007. System includes a 12 gal. Raritan 120V AC water heater with a heat exchanger from the engines.

Advice would be appreciated.
 
Personally, 2-3 times a year I just open the sink fauscets and let them run until I start to get air. As long as water is flowing the pump will not over heat.

I don't have a monitor either. I use the "Lift the floor panel and look" method. :)

Bob
 
I've emptied my water tank, but it was by accident! Make sure the line to a forward faucet is full of water. then loosen the plastic hose from the faucet and lower it into a bucket or such. The water in the tank will siphon out.

But I didn't have a bucket. In fact I didn't know the water was siphoning out into the cabin until the following weekend when I arrived at the boat!!!! Sure was a mess to clean up.....
 
Whether by siphoning or by faucet, draining the tank will still cause the pressure pump to want to pressurizing the system while the tank's draining. For the other posters, do you simply start refilling your tank with fresh water before the last of the old water drains out? Let some of the fresh water pump through before shutting off the faucets?
 
I just let it run until I see some air coming through. At that point it's not completely empty. Then close the faucet and fill the tank. Then open the faucet again and bleed out the air. Doesn't hurt the pump.

Bob

quote:

Originally posted by rapscallion

Whether by siphoning or by faucet, draining the tank will still cause the pressure pump to want to pressurizing the system while the tank's draining. For the other posters, do you simply start refilling your tank with fresh water before the last of the old water drains out? Let some of the fresh water pump through before shutting off the faucets?




 
Pull the hose on the tank, drain it, I guess I have to say hook it back up, and then refill.
 
Look at the sticky by Vic William regarding recommisioning your water system in the spring.

Bob
 
quote:

Originally posted by JimPend

Pull the hose on the tank, drain it, I guess I have to say hook it back up, and then refill.





That's far too simple! [:-eyebrows]

I drained the water tank on my Glastron each year to winterize it from 2003 until I sold it a couple months ago. I didn't ask anyone, I just looked at it and figured that if I unhooked the hose at the bottom of the tank, the water would run out all by itself. I was right, it did. ;)

BTW: The water heater has a drain also. Open a hot water valve to let air in so the tank will drain. Make sure electrical power is off to the water heater or the element will burn out when you drain the water.

One more thing: If the water pressure pump runs when you don't want it to, shut it off. There should be a switch. If there isn't, trip the circuit breaker, remove the fuse, or turn the main battery switch to "off".
 
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