Tankless Water Heaters does Anyone Decalcify Them

[DouglasReid]

I just changed out my old Girard Gen 1 Tankless WH for a Furrion model with digital temperature control.

While researching just which one to buy I learned something Id Never heard before. They need to be decalcified.

The burner, heating the water so fast so hot, causes calcium in the water to be deposited on the water side of the heat exchanger. The buildup causes a decrease in the efficiency of transferring heat and can lead to leaks in the heat exchanger and over pressure devices.This makes perfect sense to me I just never thought of it before now.

There is a process to decalcify the burner........ALL the brands should have this done on some sort of regular basis.

Does anyone else here do this to your tankless water heaters? Or are you like I was, floating along in ignorant bliss?

[montelovers]

I'm on the same boat as you floating on the same lake. I'll have to do a bit more research on this... curious on everyone else's opinions on this.
Makes sense though as a home on-demand water heater does need at least yearly maintenance so I don't see why these wouldn't need the same maintenance.

[DouglasReid]

They do need it, but since the WH in an RV heats much less than a home WH (unless you are Full Time I guess) maybe less often?

The problem is access, the hoe units have a set of bypass valves specifically designed to do this procedure, my Girard had NO such valves.

You would have had to disconnect the lines at the back of the WH and attach the lines from the descaling apparatus. Then reconnect the lines when you were done. A HUGE PITA.

When I installed the Furrion I put in two valves that will allow me to do this from outside the camper, so I think Im set. I just wanted to get others who were maybe not happy with their tankless WH to realioze what may be the issue.

[dblr]

We were upgraded from the Girard 2 to the Truma and yes it need done, Truma has tablets for theirs and the process takes a couple of hours, the control knob flashes when it needs done.

[DouglasReid]

Originally Posted by dblr

We were upgraded from the Girard 2 to the Truma and yes it need done, Truma has tablets for theirs and the process takes a couple of hours, the control knob flashes when it needs done.

Ive heard really good things about that Truma, but it is very pricey and they will not allow you to install it yourself. We went with the Furrion unit.

How long have you had the Truma and how often have you had to decalcify?

[dblr]

Originally Posted by DouglasReid

Ive heard really good things about that Truma, but it is very pricey and they will not allow you to install it yourself. We went with the Furrion unit.

How long have you had the Truma and how often have you had to decalcify?

You are correct about the price and installation, we were lucky to have had it done at the FROG Rally in 2018 courtesy of the manufacture. We average around 100 nights in the camper a year and have had to decalcify twice that I remember. I heard it depends on how much water you use but do not know how the unit knows, I just do it when the light flashes. I try to always keep a pack of tablets on hand. I figure with how much we use it plan for at least once a year or maybe every other year. Hope this helps some

[DouglasReid]

Originally Posted by dblr

You are correct about the price and installation, we were lucky to have had it done at the FROG Rally in 2018 courtesy of the manufacture. We average around 100 nights in the camper a year and have had to decalcify twice that I remember. I heard it depends on how much water you use but do not know how the unit knows, I just do it when the light flashes. I try to always keep a pack of tablets on hand. I figure with how much we use it plan for at least once a year or maybe every other year. Hope this helps some

First, it helps a LOT, Many Thanks!

No other WH that I know of has that tablet type of declassification process available, certainly not the old Girard Gen1 unit I just removed, nor the Furrion I replaced it with.

We camp around 60 days a year so I was planning on decalcifying by pumping vinegar through the WH like is done for residential units. Im planning on doing this every spring when Im readying the camper for the new years season.

[G Hollingsworth]

Our rig came with a Truma which notifies you when it must be decalcified.

In my world all manuals are obtained, read and required maintenance is always done. It’s preferable to inconvenient break downs and equipment failures.

[Doc Burry]

Our home Tankless Water Heater came with instructions to have it flushed out with white vinegar. A recirculating endeavor, with 4 gallons of white vinegar running through it, from a recirculating pump and a five gallon bucket for 3 to 4 hours. Works just fine and wise to consider doing this to yours.

[Sbosserman]

I’ve been a home inspector now for 22 years (retiring in December) and I’m not a fan of tankless water heaters in residential homes for several reasons.
1. They are 3 times the price of a tank type water heater
2. Homeowners aren’t accustomed to decalcifying their water heater, so most tankless waters don’t have that procedure performed as per manufacturer’s specifications. So failure to do that required maintenance will void the warranty.
3. My experience has been that when the tankless units do not get decalcified, they then fail at about 5 to 6 years.
4. The gas line that went to their old tank type water heater is typically only 1/2 inch and often must be either 3/4 or one inch gas piping (that must be run from the meter and can be costly) Not sure about RV propane line size requirements for tankless types.
5. Unless you have a bunch of teenagers taking long showers, do you really need one, wasn’t your old tank type sufficient in supplying you with hot water?
6. Most tankless units (unless they are very over sized) will NOT produce very hot water (over 120 degrees). Some older dishwashers (non energy star rated) will not clean dishes properly without higher water temperatures.
7. Not saving any money by buying an expensive tankless water heater after all costs are tallied (gas line, decalcifying, etc.) Remember that the average RV owner & the average homeowner will have to pay a professional to decalcify tankless units. A few of us are able to do that task ourselves. If you aren’t able to do that maintenance yourself, I’d not recommend a tankless unit.

Just my opinion for what it’s worth.

[DouglasReid]

Originally Posted by Sbosserman

I’ve been a home inspector now for 22 years (retiring in December) and I’m not a fan of tankless water heaters in residential homes for several reasons.

[QUOTE]1. They are 3 times the price of a tank type water heater

In this case the cost of the Furrion Tankless WH and the cost of a 10 or 12 gallon WH were very comparable.

How well I know. I too was clueless about this maintenance requirement. Any builder or plumber who installs a tankless WH and does not give this information to the homeowner at or before closing should be strangled.

This is one major reason I started this thread; to help educate many whose campers came with a Tankless WH about the necessity to decalcify. Our camper came with a Girard Gen 1 WH and nowhere in the owners manual did I see the concept of decalcifying mentioned at all.

Failure to maintain equipment will often cause premature failure won't it?

The units in RVs all seem to be able to obtain the necessary gas volume from a 3/8" copper line so that does not seem to be an issue.

Again some have no choice,the manufacturer puts them in, then the dealer, who is probably as clueless as I was fails to inform them of what maintenance their unit needs.

In this case the modern ones will keep the temp up to and including 125 degrees and up to 2.4 GPM,plenty to take a shower and run some other outlet in the camper.

In my case I replaced one older tankless, that does not have some of the current features, with one that does. Time will tell if I made a good decision or not.

We all have them and yours are as valid as anyone elses....Maybe better based on your experience.

I do have one question for you though.........How do you feel about a well maintained tankless WH as opposed to say a 6 gallon conventional RV WH?.

[CampinGpa]

How do you do the maintenance on this tankless hot water heater I have a 2018 Cedar Creek Hathaway Edition that has it and works good did not know anything about any type of Maintenance that needed to be done your help is very appreciative

[Leadbouncer]

My electric stopped working. Now I just run the gas. September appt coming up. Not looking forward to it.

[Sbosserman]

I don’t think you read my opening sentence: “I’m not a fan of tankless water heaters in RESIDENTIAL HOMES for several reasons:”

Tankless water heaters haven’t been used in Rv’s for very long, so they really don’t have much of a track record. They have been used in standard residential homes for some time now and HAVE begun to develop a track record. THAT is where my experience lies and I was trying to extrapolate that experience into what people should expect from their RV tankless units.

The costs I was referring to are RESIDENTIAL tankless units versus RESIDENTIAL tank type units, NOT RV units. Residential tankless units ARE easily 3 to 4 times the price of tank type units especially when you consider ALL the installation costs (gas line size increase, etc.)

Failure to drain & flush tank type water heaters annually has not had much of an impact on their life. Just ask yourself when was the last time you flushed you home water heater tank? How long did it last? I’ve never flushed my tank type and it is from 1986. My point here is that tank type water heaters are forgiving for lack of maintenance, tankless units are NOT.

My reference to 1/2 inch versus 3/4 or one inch gas lines were Referring to RESIDENTIAL units as they have a MUCH LARGER capacity than RV units.

As to maintaining 125 degrees, I’m thinking that you are again referring to RV tankless units. That may be the case as I haven’t had experience with the RV tankless units, only the residential units. I was trying to make a comparison between the two. But, the only time I have seen residential tankless unit be able to maintain a water temperature high enough that you couldn’t hold your hand under for 5 minutes, was when it was very much oversized above the manufacturer’s recommendation. Typically, residential tankless units put out very warm water, but not hot enough to burn you.

Only time & experience will tell with RV tankless water heaters. But I’m VERY skeptical due to my experience with residential units. Maybe because the RV units typically only get used for several weeks per year on average, they may last a reasonable time. But don’t kid yourself about the decalcification requirement, you’d better be doing it or you’ll be shocked at the shorter life, because tankless units are unforgiving for lack of that maintenance!

[DouglasReid]

Originally Posted by CampinGpa

How do you do the maintenance on this tankless hot water heater I have a 2018 Cedar Creek Hathaway Edition that has it and works good did not know anything about any type of Maintenance that needed to be done your help is very appreciative

There are numerous You Tube videos about how to descale tankless water heaters but unfortunately they are all about residential tankless units. The good news is that descaling an RV unit is precisely the same, sop says the manufacturer of my new WH, Furrion.

Their instructions is to pump vinegar through the WH to decalcify it. The only way this could be done is to have access to the rear of the WH. Then disconnect both the Hot and Cold lines (after blowing them out with air so the water in the hot and cold lines does not leak all into your camper) from the from the WH and connect up the hoses there. NOT an easy or fun task in most RVs. Then flush out the vinegar with fresh water and reconnect the water lines to the WH.

You will also need to shut off the gas. You need to close the bottles then burn out the residual gas by turning on ,say, your stove until the residual gas pressure in that system is used up. NOT difficult but it needs to be done so the unit does not fire up during the decalcification process. You also need to turn the power switch to the WH OFF.

I was fortunate, I have good access to the plumbing through an access in our pass through and I was installing a new tankless WH. I connected up two 3 way ball valves to use to isolate the WH from the rest of the system, and ran two lines to the exterior cabinet where my fresh water connection and dump valves are. Now connecting the pump and vinegar will be easy and done external not internal to the camper.

If you are interested I can post a link to the install thread if you like.



Happy Camping

[DouglasReid]

Originally Posted by Sbosserman

I don’t think you read my opening sentence: “I’m not a fan of tankless water heaters in RESIDENTIAL HOMES for several reasons:”......................................... .........

Only time & experience will tell with RV tankless water heaters. But I’m VERY skeptical due to my experience with residential units. Maybe because the RV units typically only get used for several weeks per year on average, they may last a reasonable time. But don’t kid yourself about the decalcification requirement, you’d better be doing it or you’ll be shocked at the shorter life, because tankless units are unforgiving for lack of that maintenance!

I read your post and fully understand you wee referencing residential Tankless units, those with which you have had experience.

I was merely pointing out the differences between the residential units (in a previous life I was a Residential Building Contractor) and RV units. No intent to discount your input, in fact it was all helpful I think.

It seems the RV units are getting much more sophisticated and powerful. My old Girard Gen 1 put out a max of 32,000 BTU, my new Furrion puts out 60,000, able to heat 2.4 GPM up to its max of 125 degrees. We have it set on 115, and our first trip with it is next weekend,...we shall see.

As for the skepticism, that old Gen 1 was one of the main reasons the previous owners sold the camper, they Hated it. It was finicky and temperamental.........which is why I replaced it.
We are sort of on the same sheet of music here

[nomad297]

Most residential tankless manufacturers will not honor a warranty on (at least) the heat exchanger if the water being supplied to it measures more that four grains of hardness per gallon. There’s not too many municipal, and even fewer well systems that provide water with less than five grains of hardness. This is something that is almost always overlooked or ignored by installers of tankless water heaters. With just about every tankless water heater installation, a water softening system should also be installed, increasing the overall installation cost by a couple/few thousand dollars. This is a dirty little secret. Most people wanting to convert their tank-type water heater to a tankless water heater wouldn’t do it if the installer was honest or knowledgeable because the cost would just be too much.

Then there’s the gas supply thing. Too many installers just ignore the undersized gas system. On a standard low pressure gas system, right from the get-go, there is a sizing problem. Most residential gas meters for low pressure systems are designed to provide 250CFM (250,000BTUH) of gas. Most standard residential tankless water heaters require around 190,000BTUH, so that leaves about 60,000BTUH available for all of the other gas appliances in a house. So, in the winter when your furnace is pulling, say, 80,000 to 110,000BTUH, your gas fireplaces are pulling 30,000BTUH each, your gas dryer is pulling 40,000BTUH and your oven and range are pulling whatever they are pulling, each and every one of your gas appliances is underperforming (or not performing) and destroying themselves. So, in most cases, the installation of a tankless water heater requires a larger gas meter to be installed. Then, from there, either the entire gas system needs to be resized and replaced or a dedicated line needs to be run form within one foot of the gas meter to the tankless water heater.

Then there’s the combustion air thing. A 190,000BTUH tankless water heater requires a lot of combustion air and most installations don’t provide for enough cubic feet of air to satisfy this, so a two-pipe combustion air and exhaust system must be installed — one pipe to draw air in from outside to the water heater and another to exhaust the spent gaseous air to the outside from the water heater. These pipes must be strategically placed outside with consideration for window placement, wall protrusions, inside and outside corners of the building, average snowfall accumulation for that geographic area, etc, etc.

There are several other considerations than what I have mentioned, and very few installers consider any of them unless they are getting the installation inspected by a municipality that knows what they are looking at, which is a rarity. Many homeowners install these things themselves and have no clue of what they are getting themselves into and the problems they will be causing.

In most cases, converting from a residential tank-type water heater to a tankless water heater SHOULD cost much more than three times what it would cost to just replace their tank with another tank. Even doing this nowadays isn’t as simple and inexpensive as everybody thinks. Today, to replace a tank-type water heater vented into a masonry chimney, the chimneys must be inspected and almost always need to be lined, but, again, most installers and homeowners just ignore this safety issue and swap them out with no consideration for the lives of those in the house.

Almost every tankless and tank-type water heater installation I see is not correct.

Bruce