On Demand Water Heater Control Issue

[Mlalonde]

Good morning all and Happy Thanksgiving! So much to be thankful for today so I'm going to keep things positive but I need some expert help. I'll try to be brief.

2020 Alpine 3851RD purchased brand new about 2 months ago. Currently on third camping trip.

Unit has Suburban Nautilus RL tankless HWH system. Trip one, works like a champ. Trip 2, no hot water (I'll explain), then to dealer for three weeks, found no problems found, then trip three (where I'm typing this) no hot water.

Symptoms. HWH is propane only and propane is on and working fine (all other propane systems function like furnace, stove, etc.). So I have gas flow.

System uses "On Demand" control panel. Turn unit on, no spark, flame or fan icons. Displays temp desired and the little "play" icon representing the recirculate heating option (which won't turn on or off by the way). Run one, multiple, all hot water faucets to create flow. Great water pressure (even removed the water pressure regulator just in case). Won't show it's trying to spark, heck, won't show anything on the display except temp and "play" icon. Then after 30 seconds, shuts off (on demand goes back to "off" status). I've read everything I can find on the internet and in the manuals to no avail. I sense that my HWH is ok but the control panel is not functioning properly. OR the flow sensor is just not working. Why the dealer said no problems found is beyond me. They said "110 degrees is not hot enough to make it work and you need to be at 120". OK, so I changed it. Now it's even on 130 and still no hot water so..... Yeah.

Anyone ever have this issue and if so, is there some level of reset, etc.?

Again, we're blessed. Here at a great KOA in Oklahoma (casinos are open on Thanksgiving). They have hot water showers so I can't complain. But I'd like this resolved without taking it back to the dealer again (so they can keep it for another month) and them not fix it.

BTW, currently on city water connection, full hook ups. Might try to fill the fresh water holding tank and use the water pump to see if it makes any difference. Can't imagine it would.

Thank in advance, all for any input that may help.

Mitchell

[ChuckS]

I’d check the manual Eco switch...see attached pic and also I’d do a reset of BCM

[Mlalonde]

Thank you sir. I'll give that a shot. Much appreciated. I'll post and update after I try it.

[Mlalonde]

Originally Posted by ChuckS

I’d check the manual Eco switch...see attached pic and also I’d do a reset of BCM

Worked like a champ! Thank you sir.

[ChuckS]

Glad to hear things are working again

[falconetti]

Just an FYI residential tankless get destroyed by hard water. Heat exchangers and flow switches are always on the mend and residential manufacturing requires a water softener for anY warranty claims. I plumbed in a mini water softener in our raptor. Sits under my slide. Regenerates automatic and dumps
Into my flush fitting on my slinky.

[lunge motorsport]

Great comment Falcon


I would add that in my experience as a residential/commercial tankless installer and service provider that while salt based softeners do remove TDS from the water there are still heaters that suffer from heat exchanger failures with softeners. I advise my clients to add a scale inhibitor system to the supply side of the water heater. There is a small system by Aqua Pure called an AP 430. It does not filter but is an emitter of sorts. Very small and compact and piped using 3/4'' npt female thread connections.


Another consideration is air quality. Dirty air will foul flame rods, clog the gas manifold and burner ports.

[ChuckS]

I’m glad I have a plain Suburban water Heater

[sourdough]

Originally Posted by ChuckS

I’m glad I have a plain Suburban water Heater

^^^^x2 - 100% agree.

[JRTJH]

I think the move to demand water heaters came when Keystone installed a soaking tub in the Montana line "front luxury bath" models. A 12 gallon water heater simply could never provide enough hot water to fill a 50-60 gallon tub. So, the "work around" was the demand water heater. It works well (in theory) but not so well (in implementation)....

We had a "flash water heater" in Turkey, a propane model that hung on the wall beside the kitchen sink. Any time someone turned on a hot water faucet, we'd yell, "FIRE IN THE HOLE" to warn anyone standing at the kitchen sink to duck.... If not, the flashback from a delayed ignition would "singe the hair on your head"..... I'm not a fan of demand water heaters, in homes or in RV's....

[Mlalonde]

Haha. That's crazy! But hey! Never a dull moment right?

As for the mini salt based softener, already got it. I live in a part of Central Texas that has taught me lessons about hard water. So I'm good as far as an in-line softener goes. As for the other part I'll definitely look into it. Makes total sense.

I like having instant and relatively unlimited hot water. I don't, however, like new things that are a pain in the backside to work on and will likely break when you need them most.

All, I truly appreciate the input. Well noted.

[LHaven]

Originally Posted by lunge motorsport

while salt based softeners do remove TDS from the water there are still heaters that suffer from heat exchanger failures with softeners.

In the course of figuring out why my home water softener "wasn't doing anything," I discovered last year that salt-based softeners remove only part of the TDS from your water (the part that characterizes "hard water") but there are a whole lot of other DS that go right through them and sediment things up. I discovered that our well out here has massive TDS, but perfectly soft water.

[falconetti]

Originally Posted by LHaven

In the course of figuring out why my home water softener "wasn't doing anything," I discovered last year that salt-based softeners remove only part of the TDS from your water (the part that characterizes "hard water") but there are a whole lot of other DS that go right through them and sediment things up. I discovered that our well out here has massive TDS, but perfectly soft water.

Ion exchange softeners They remove calcium lime and magnesium, well water can require more extensive treatment. I'm pro softener for the RV, descaler units are a great no maintenance option as stated above. I will never have a tank style heater in my RV, I do not like having a limit on hot water. We would run out in the Montana when the kids were with us.

[Nathan]

Hey everyone..I’m dealing with my hot water not flowing in my new 2022 keystone alpine 3700FL. I know it’s on demand and It worked fine the night before I’ve only had this new rig for 2 months now and I’m not sure on the location of everything just yet..can anyone please throw me a bone if you know these problems?

[ChuckS]

Have you tried opening up, the small access panel on the on demand water heater and pressed the reset switch and try the hot water faucet again?

Images from a document I created for the Alpine group

[Nathan]

No I haven’t..I’m not sure where that’s even at! I’ve looked everywhere but no luck!

[ChuckS]

Locate the water heater and there is a small access panel. Remove the panel and you will be looking right at this PCB. Press the reset button and try the WH

The WH is behind the single exhaust duct on the outside of your Alpine

[Nathan]

Ok thanks I’ll let you know when I try it..thanks

[Mikendebbie]

ChuckS - that is good info to know! Thanks!
Nathan - search for videos on IW60 installation. Lots of good videos that will help you.

[Nathan]

Ok thanks I’m out of town right now but I should be back tomorrow.. in the meantime I will look that up I appreciate everybody’s help thank you! I’ll let everybody know tomorrow if I got a fix or not..