Hot water heater calcium deposit advice needed

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OK2NV

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May 14, 2018
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Hello all, I am looking for some advice on cleaning calcium deposits out of a gas/electric water heater. Didn't think to look at the make and model of the hot water heater but it is in a 2003 Fleetwood Revolution. We have had sporadic issues with our bathroom faucet getting stopped up with calcium deposits before but this past week we camped for 5 days over the Thanksgiving Holiday and by Sunday everything but the toilet was down to a trickle and the bathroom sink faucet is completely stopped up. Has anyone had good luck getting calcium deposits out of their hot water heater? We are in Kentucky so I know our water is hard.

I was contemplating mixing up a solution of CLR and running through the hot water heater but after a quick Google search I don't think that is a good idea. Some people mentioned using vinegar and others mentioned just flushing the system out with normal water so I am not certain what to do. Any suggestions? As of right now we aren't scheduled to camp anymore until February but would like to remedy this before I winterize. Thanks.
 

Henry J Fate

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Vinegar works fine. You will need to isolate the tank and let the mix sit in there for a couple of days then flush it out with a flush tool. Camco sells one but you can make your own.

If the water heater is bad then certainly other components are probably in need of attention. Each faucet has an aerator at the faucet end and should be removed cleaned or replaced. While you have those off, flush each hot and cold line out.

There is at least one backflow device (possibly 2) in the plumbing of the hot water heater that could be acting up from the high calcium levels.

Calcium at proper levels is healthy but like anything, too much will cause problems. If I plan to camp at a known high calcium water hook up, I always fill my fresh water tank with some good water before I leave and try to use that supply. Filtering calcium out of the water is a little complicated and requires more than just an ordinary filter system.
 

Rene T

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Not all water heaters have a back flow protector. I had a King of The Road fifth wheel and it had a three valve bypass system so no need for a check valve.
 

House Husband

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Your Fleetwood coach has an aluminum Atwood water heater. Yes it has a check valve on the outlet port, and uses a 3 way ball valve for winterizing by-pass.
I use 1/4" copper tubing, smashed mostly closed with a slight bend on the end to flush out deposits, through the drain port.

Richard
 

Kirk

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Do not use CLR in any place that you may ingest the water. The first thing to do is to turn off the water heater and let it cool and then drain it and use a flushing tool on your water hose to flush out the collected calcium deposits in the bottom of the water heater tank.
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I do this annually and am always a little bit amazed by the amount of calcium deposits it will remove. By rotating the tool around you can spray it up into the burner area and it will know a lot of the deposits loose but there will also be quite a collection in the bottom of the tank. On occasion I have also done a flush with white vinegar to clean up the interior, but as a general rule it is only needed after an extended stay where water is very hard. Directions for that here.
 

Henry J Fate

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Not all water heaters have a back flow protector. I had a King of The Road fifth wheel and it had a three valve bypass system so no need for a check valve.

There should always be a check valve in the cold supply line to the water tank. That check valve prevents the hot water from getting into the cold water lines which is caused by thermal expansion.

Some designs have placed another in the hot water line at the tank. That check valve can affect how bypass valves for winterizing are set up.
 

8Muddypaws

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The bad news is that the Atwood has a mixing valve on the back of the tank that gets deposits too. Not hard to change if you have access to the back of the tank. Might be time to replace the electric element as well.
 

Gary RV_Wizard

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Only the XT model Atwoods have a mixing valve. The standard 4/6/10 gallon models don't do any mixing.

Mineral salts from hard water collect in the bottom of the tank and around valves, so the answer is to flush them out periodically. With the heater off and water supply off, remove drain plug and flush with a hose (others have already discussed this). Refill the tank, cycling the winterizing valve to direct water thru its various positions, removing any loose grains of salts there. You can soak the tank inside with a vinegar solution, but it's not going to do much with the aluminum Atwood tank liner. Any minerals are either stuck there or fell to the bottom of the tank already.
 

Mark_K5LXP

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Photo below of what came out of my water heater the first time I used the Camco wand. Not sure if this is water scale or the interior of the tank sloughing off. I do know that the PO did some full timing in it so the water heater has probably seen some extended use. I ended up buying a combo anode rod/drain plug and we'll see if that makes any improvement going forward.

Mark B.
Albuquerque, NM
 

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Kirk

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I ended up buying a combo anode rod/drain plug and we'll see if that makes any improvement going forward.
This is good advice for a Suburban water heater but not for an Atwood as they use an aluminum tank and the addition of an anode will violate the warranty and destroy the tank.
 

Mark_K5LXP

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This one is specified for Atwood:

Camco 11533 4.5” Anode Rod with Drain for Atwood Aluminum Water Heater​

  • 4.5” Magnesium Rod for Atwood style aluminum hot water heaters
  • It preserves the life of the water heater by corroding itself so the water heater tank doesn't

Mark B.
Albuquerque, NM
 

Aaron5er

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I bought a used 2013 rig this year and flushed the water heater back in the spring after getting it home.

The anode rod was disintegrated and clogging the threaded nipple. I used a flush wand and got a cup or two of trash out of the tank like Mark did, along with the rusted steel rod.
I wonder if it's ever been flushed by the previous owner.

We were on the road 4 months this summer, winterized last week and flushed it out again.
The new anode was about half gone, flushed about a quarter cup of trash out.

I'll flush it again really good when de-winterizing and clearing out the antifreeze from the pipes.
Never hurts to keep it as clean as possible.
I only use water through the wand like Kirk and Mark.
 

Gary RV_Wizard

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Photo below of what came out of my water heater the first time I used the Camco wand. Not sure if this is water scale or the interior of the tank sloughing off
It's just normal mineral salts that precipitate out of the water during heating cycles. Nothing to worry about but good to wash aways in case it builds up enough to clog something up.

That Camco Atwood anode is totally unnecessary and just a ploy to take some money from you.
 
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