About every three months, we clean out our hot water tank by
removing drain plug and flushing with a 'wand' connected to a
hose. We let the drain water flow into a bucket so we can
'capture' the junk that flows out.
Today we had more than a handful of white pieces and size varied
from very fine to 1/4". Even took photos of the collection.
Are these formed because we use a hot-rod 110 volt heating
element to heat water?
The rod always has a white hard coating that I scrape off before
I put it back.
I do not heat water with propane very often, but maybe the same
thing would happen.
Do others drain their propane hot water tank (non-Aquahot)?
And do you see these pieces? Are they calcium deposits?
They have clogged the screen in our hot faucet in the past.
I assume you have an Atwood water heater. If so, read on...
The tank is made of aluminum. Iron and other minerals in the
water cause a galvanic reaction-- the white precipitate is one of the
byproducts. Aluminum is much less noble than iron, brass, etc,
so the aluminum tank acts as the anode, sacrificing itself to "protect"
the more noble metals.
And the presence of a hot rod which is likely iron or other
metal more noble than aluminum does accelerate the process. As does
the presence of any stray electric currents.
Best advice (from Atwood) is NOT to use a hot rod. And to
the tank at least once a year with 50/50 cheap white vinegar/water.
Also, I "vacuum" the debris from the tank bottom with a 5'
length of cheap clear plastic hose that will just fit into the drain. Just
start a siphon and move it around the bottom until nothing else
comes out. You may have to have an assistant "bump" the water pump to
refill the tank a time or two to get all of the precipitate out.
Buy a water heater flushing tool from an RV store. It's a 18"
long piece of 1/8" copper tubing with a bend near the end, with a
valve and hose connection at the other end. After you drain the tank
(every 6 months) insert the tool into the drain fitting and keep flushing
until no more white deposits come out. I've followed this approach
full-timing for years and never had an Atwood water heater fail
from corrosion, using electric most of the time.
We have had your tank flushing tool for many years and use it
about every 3 months.
We drain tank, with pressure-temp safety valve open.
When we use the flushing tool, lots and lots of calcium looking
hard deposits come off.
Sometimes, there is not much debris, so I figure it is the
quality of the water that when heated drops its hardness.
Just we are always are surprised how much stuff is in the tank.
And our outside hot water faucet has a screen in the valve, that
sometimes clogs up.
Thanks for letting us know someone else has seen this.
We also have been doing this for 14 years of full timing and
have not replaced a hot water heater, which includes both Suburban and
One thing, I noticed is just draining and refilling water does
not loosen any debris.
The flushing tool you mentioned is absolutely required,
otherwise there is not much value in draining.
And I guess flushing more often prevents large buildups.
Barry L 7/28/08
I can't compare this procedure to the flushing tool, since I
don't own one, but I've had some success with draining the hot water tank
while I've had external water pressure available. While external water
supply is hooked up, turn it off temporarily until tank is empty
then turn it back on and watch the crud flow out of the tank. Turn
off the water and let the tank drain again. Keep doing this until the
tank drains clear. This is probably not as good as the flushing tool
but it will rid your tank of the majority of "stuff".
Bob Perker 8/28/08