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Old 12-31-2019, 07:15 AM   #1
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Join Date: Nov 2018
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M.O.C. #22972
change water heater

We have a tankles water heater in our home ,I just noticed some full timers have them in there RV . Can I get any feed back on how they operate ,who would install them and how prone to problems are they. We are leaving Charlotte NC Sunday to have disk brakes and IS installed on our 3720 RL next week ,Thanks for any feed back , Jerome & Judy
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Old 01-01-2020, 10:05 PM   #2
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I didn't install mine but rather ordered my rig with it. Endless hot water. Only issue is when water temp coming in gets real cold I have to slow down the flow of hot water some, otherwise it may only get to 100. Heat tape and insulation on the outside water line helps line from freezing and can up the temp some coming in.
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Old 01-02-2020, 10:07 AM   #3
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Only bad problem with tankless is the hot cold sandwich while showering. There are steps that you can take to minimize it but it’s there. For the tub and everything else it’s great. My neighbor just spent 1500 to take his tankless out of his diesel pusher and install a tank system.
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Old 01-02-2020, 11:04 AM   #4
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Where we winter in NM it can get pretty cold at night. Three rigs on our street have them and wish they didn't. The problem indicated above is the reason, plus the propane usage when you're paying for electricity anyway. If you don't camp where it gets very cold or if you aren't annoyed by cool showers in the winter then the tankless water heater is for you.
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Old 01-02-2020, 11:08 AM   #5
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There are steps to minimize the sandwich effect. I have gotten it down to cool water instead of cold !! That helps, while hooked up itís nice we never run out. I think they need a small tank integrated with the tankless, to allow for hot water until the flow sensor kicks in. My 2cents.
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Old 01-08-2020, 06:43 PM   #6
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I'll put my two cents in as a contractor. Quite frankly I'm learning with this post about them in RV's. They've been in residential homes for a long time and I installed my first whole house unit in 1999. The problem with tankless heaters is they work on temperature rise. The colder the water coming in the less hot water temperature they can produce. The other issue is for electric units minimum amperage is around 40-50 amps. For natural gas or propane you have to have a big enough boiler to make them effective with 100K BTU's at a minimum. If you're only running one faucet or a shower both with low flow heads it may work but the more flow you have the bigger the unit has to be. I just wouldn't think that either of these would be viable for an RV unless you have a big tank or hooked up to natural gas. The smaller the unit the best way to run them is to not add any cold water. I don't know about the RV ones so good luck on those types but the residential ones work great.
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Old 01-08-2020, 07:55 PM   #7
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On demand water heater

When we first bought our unit (late January 2018) we were on temporary assignment in Fort Worth. Temps had been cold (by TX standards) in the 20s and 30s for several weeks. I did notice the on-demand water heater did not put out very hot water...but it was still good. DW would add a pot full of boiling water to her bath. We have not had any issues with it since. HOWEVER...

We are in TX. The ground does not get very cold here to chill the city water pipes...maybe 60*...so the on-demand water heater has been friggin’ GREAT! Repeat GREAT! Granted - we have not traveled during cold months up north. This topic has come up from time to time and I can completely sympathize with the less than glowing reviews from those folks in colder climates. I think if we did lived where the ground got real cold (and therefore the water coming to the RV was real cold) - I would try to find a way to pre-heat the water. Not sure how I would do that but I would start researching for a portable water heater (like below) to see if it can be adapted for use with an RV. I would need to figure out where to put it and protect it from freezing. Maybe get a separate propane tank to feed it. It might be the best $300 accessory to have.

Disclaimer: I’m just throwing the idea out there because I agree that in cold climates the on-demand heater may not perform like I wish it would.
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Old 01-11-2020, 04:11 PM   #8
DebNJim B
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Glad to see this thread. I have a Ranai on demand tankless in our s&b and we love it You can have 2 taking a shower and do laundry in the winter up north when the incoming water is in the 40's and not have a problem. I had thought it would be nice in the RV but the cost to convert is quite high and we run on electric most of the time. We have no problem with showers as long as I get the first one as DW likes to keep the water running. I stop it while soaping. Hearing about issues in cold weather I'm definitely sticking with the stock WH.
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