Maiden Voyage Question #2 (hot water)

BandJCarm · 05-11-2016, 08:10 PM

Have on demand hot water system. I have read the threads about bypass valves in wrong position. BUT...........I admit I've gotten confused. Now, I just got in from a 3 day long trip, and I'm beat mentally (bad week last week), and so type s l o w l y.

Hooked up last night in Nashville (halfway home from dealer, just pulled in an hour ago). I finally figured out which button turned on hot water (there is a water heater switch, and a 'tank' heater switch.......the 2nd on is for.....I dunno since there's no tank). But turned the first one on. Had hot water even though I had to wait a while. Wife took shower........all fine.

I got in 5 minutes later............had hot water.......for half of a shower! Then cold!

Attached are two pics of current settings of valves. This was explained in walkthrough yesterday morning, but I admit I'm brain fried and confused.

Is this possibly the issue? What is the 2nd 'tank' water heater button for?

I thought an on demand hot water system would heat water as long as there was intake water.

????

jtaylor1920 · 05-11-2016, 08:24 PM

Can't help with the on demand water heater but the tank heater switch is going to be for your holding tanks. There are electric heat pads on each of them to keep them from freezing in cold temperatures.

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grumpy0374 · 05-11-2016, 09:36 PM

Don't know what lines lead to where, but one of your valves is in the closed position. Valve handles/knobs, when open are parallel to the line. In your pic's, one of the valves is closing off the line. Its the valve on the white hose comming from the very top of the pic.
Grumpy

BandJCarm · 05-12-2016, 10:37 AM

White hose is for winterizing, drawing in antifreeze.

Guy that has one of these says he can't see anything wrong with valve situation.

Leads to a question.........is "on demand" hot water unlimited as long as there is a cold water supply, or not? If not, what makes it 'run out' of hot water????

Guess I don't understand how an on demand hot water system works........

5picker · 05-12-2016, 10:50 AM

On demand water heaters are supposed to keep up with demand. (hence the name)

Yes, as long as there is water to supply the tank you theoretically should have hot water.

I don't believe anything is wrong with your valves but I suspect something is amiss with the portion of the tank that actually heats the water. That would be propane.

Could be the tank(s) are empty, bad regulator, control module, went into lock-out, etc.

Start with... do other LP appliances work? Stove, oven?

BandJCarm · 05-12-2016, 12:39 PM

Quote:

Originally Posted by 5picker

On demand water heaters are supposed to keep up with demand. (hence the name)

Yes, as long as there is water to supply the tank you theoretically should have hot water.

I don't believe anything is wrong with your valves but I suspect something is amiss with the portion of the tank that actually heats the water. That would be propane.

Could be the tank(s) are empty, bad regulator, control module, went into lock-out, etc.

Start with... do other LP appliances work? Stove, oven?

Thanks. I wondered about that. What puzzles me is, that after a while, the water came back hot again........just like it would if it were heating a water tank.

??

clr · 05-12-2016, 12:50 PM

Many RV people on the forum have replaced the on demand how water tanks and gone back to a conventional water heater. With an on demand type water heater you have a flow sensor in the water line to the unit so that it can determine demand. The problem with the flow sensor is that bubbles in the water line will disrupt the reading and the water heater is not able to determine the demand (water flowing).
The simple fix is to run all the water outlets until there is no air or hissing or spitting caused by the air in the lines. This should correct the problem but of course you will have to repeat when you move or such.

NMWildcat · 05-12-2016, 01:12 PM

I thought I read where you had Girard tankless, but looks like I was mistaken!
Sounds like your tankless might have problems with one of the sensors. I would call the manufacturer direct and see if they can help They will usually walk you through some tests and offer advice.

We have the Atwood tankless and would never go back to a conventional tank heater. The Atwood does not seem to be bothered by air in the lines or what water supply you are using. The water temp doesn't fluctuate and we can get it as hot or cold as we desire. Usually only using the hot water knob. The only time we add cold water is when we are in Phoenix/Tucson where the cold water is already pre-heated

The only change we made was adding the oxygenics shower head which greatly increased the feel of the shower and allows more control of the flow rate.

BandJCarm · 05-12-2016, 02:00 PM

Just asked dealer. It's a Suburban.

I have no clue WHERE it is.........LOL.......or what it looks like.

NMWildcat · 05-12-2016, 02:34 PM

It will have an exterior door panel with a heat exhaust in it. When you find it I would double check to make sure there isn't a tank

I would call their techies and describe your problem with the tankless. Can't hurt! It should never stop heating the water, then magically start up again. I know mine has an exhaust flow sensor and a water flow sensor and some others that I don't have a clue about

But any of them malfunctioning could cause your symptoms.

I have had to go out and re-seat the wiring connectors on mine occasionally. Like everything in an RV it all works loose sooner or later.

Here's some info I found for Suburban:

Customer Service
Phone: 423.775.2131
Fax: 423.775.7015

Service Department
Phone: 423.775.2131
Fax: 423.775.7015

They also have some docs and FAQ here:
Service / Support

Good Luck!

BandJCarm · 05-12-2016, 02:35 PM

Thanks man. Love this place.

I guess this is going to have to wait. Got to leave in morning (no trailer) for 2 weeks. I can't call now and have them walk me through stuff, no time. I will do all this when I get back.

I can live with most anything...........but not cold water!!

Well.....lack of ice would be worse, but................LOL

BandJCarm · 05-12-2016, 03:00 PM

Dealer say that Factory says Suburban IW60 model.

AandJWV · 05-12-2016, 04:48 PM

Have the same setup in my 2017 and had the same issue. The pics show the correct valve positions. I also had the tank work sometimes and not others. Have not had time to contact Suburban yet, but, when I had that happen, all I had to do was, on the inside control panel, turn off the tankless heater switch and turn back on. Worked fine. Could be several things, but for the time being, kept the DW's shower warm.

BandJCarm · 05-12-2016, 04:54 PM

Quote:

Originally Posted by AandJWV

Have the same setup in my 2017 and had the same issue. The pics show the correct valve positions. I also had the tank work sometimes and not others. Have not had time to contact Suburban yet, but, when I had that happen, all I had to do was, on the inside control panel, turn off the tankless heater switch and turn back on. Worked fine. Could be several things, but for the time being, kept the DW's shower warm.

Thank you sir.

Good info!

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