descaling a tankless water heater

Feb 28, 2009 17 Replies

We remodeled and put in a tankless water heater in fall of '06. The guy who installed it was here to do a small plumbing job and mentioned that the factory recommends a descaling flush once a year (which he'll do for $200). I can't find anything in the manual about such flushing so am wondering what any of you who might have had experience with these systems have to say. I don't doubt that there'll be scale build- up over time; I'm mostly wondering about frequency (and cost).



Thanks.



Lynn Willis San Diego


I have one, a Bosch Aquastar 117000 btu unit. I would do it every year or more if needed. have a valve instaled at the top that allows you to enter a delimer. And a drain valve to flush it at the bottom.

Sounds more like decashing your wallet.

Repost problem sinnce you contacted me, but its DIY

Here is just one of the kits to flush your tankless. Notice it takes the solution AND the pump kit. Basically about a $210 kit. Is it needed? I dunno. Probably, but check your manual and contact the manufacturer. Bubba

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arent tankless wonderful..........

I'd want to do some internet research, first. See if any of the manufacturers reccomend that. Since tankless have such a small water capacity, I doubt they would have much scale build up. Just for fun, you could ask the guy what's the procedure, and let us know. Might be a good scam alert.

Very helpful information. Thanks.

Lynn

He told me that they hook up to a circulating pump and run a deliming solution through the tankless system for an hour. Sounds like the $210 kit that Bubba described. Also sounds like this is a do-it-yourselfer. I plan to call Noritz on Monday to see what they say about deliming.

Lynn

Tankless only heat when the water if flowing unlike a water tank. I never heard of descaling a water tank where scale is more likely to build up with standing water while heating.

Oh great!

A $200/year added expense to the "money-saving" tankless scheme.

yeah arent they wonderful:)!!!!!!!!!!!!!!!!!!!

Yup. There's always a catch, although if this procedure turns out to be a necessity (I'll let you guys know what I learn from the Noritz folks), AND it's something a klutz like me can do, it'd probably be worth buying the pump. Then it costs only for the deliming solution. We shall see.

I'll be back...

Lynn

Exactly. They cost a lot to purchase including cost of the unit plus possible electric or gas supply upgrade. Now it seems these flush solution kits are showing up at $200 a pop. I dont have one and dont know but personally, my situation doesnt require a tankless. For the most part, if you are in need of a virtually endless supply of hot water, a tankless would be one alternative. Just not my alternative. I like my tank full of hot water. Bubba

I wonder if the deliming solution which is probably a acid will lead to a leak one day?

yeah i like my tasnk full of hot water too:)

I remove sediment from toilets with muratric acid it works well

aaronrobertson had written this in response to

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: Descaling is necessary with most tankless units every year to maintain efficiency and lengthen lifespan. It's not difficult. Just fill the heating chamber with vinegar or CLR or LimeAway, let it soak, and flush it out. DO NOT pay someone $200 to do that for you. Webstone makes special valves that connect to the inlet and outlet - they make the process much easier.

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You're correct, on all counts. Noritz recommends the annual cleaning and suggests that it be done with a recirculating pump. Recirculate or not, the job is a do-it-yourselfer, so I think I'll tackle it myself and see what happens.

Thanks to all for the comments and suggestions.

Lynn

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