On Demand Water Heaters

[judymusic]

Does anyone have one? We just had an Atwood Instantaneous water heater installed. We have to run water for minutes rather than seconds to get hot water. This can't be right because if we were on fresh water tank rather than hooked up to a continuous water supply we'd run out of water just waiting for hat water.

Thoughts? Is this normal?

[RickO]

Hi and welcome to the forum.

It does sound unusual to have to run water for minutes waiting for it to get hot. Has the new unit you installed solved the problem? You mention this long wait time being a challenge when not on hook ups... but I would think the instant hot water systems must use more power to operate so does this just trade one boondocking challenge with another?

Rick

[judymusic]

This is the new unit with the problem. The on demand water heater is gas.

[MitchellPnw]

Maybe your flow is to high. Try only turning on the hot water half way. See if that helps

[kbhine]

We have one at our home. It does take a bit for the water to initially get hot. Once it is hot though, you won't run out of hot water, as long as it is running.

[Lac]

Hi and welcome. We had a version 2 Gerrard tankless hot water system I. Our Windriver TT.Outdoors RV replaced it this year under warranty with a 6 gallon gas/ electric tank style. We where not happy with the Gerrard. They had numerous complaints of extreme fluctuating water temperature. Your may be different. Ours was very noisy and only ran on propane only. If you dry camp the endless hot water will depend on how much water you have in your water tank. If you use full service sites you have to use your propane as it dosen't heat by electricity.
Outdoors RV man. And Artic fox do not install tankless systems in their units.

IMHO would not have one and glad its gone.

Coops

[94-Newmar]

Originally Posted by judymusic

Does anyone have one? We just had an Atwood Instantaneous water heater installed. We have to run water for minutes rather than seconds to get hot water. This can't be right because if we were on fresh water tank rather than hooked up to a continuous water supply we'd run out of water just waiting for hat water.

Thoughts? Is this normal?

These are excellent water heaters, I have installed many of the Atwood and Gerard units - both work very very well. There is a potential problem with the Atwood that is easily corrected (oversight from the factory) but must first determine IF it's activating/lighting the very moment you open any faucet's hot water supply.

If you are unable to hear the unit activate/light while doing this test then have someone else stand outside near it while you open a hot water only faucet - the unit should light instantaneously and immediately when you open any hot water tap.

(1)
If it does not light/activate, call Atwood with your Model & Serial number and they will happily send you a part that you can easily replace yourself. It's within the pressure sensing switch which was set too low, thus it doesn't believe that a call for hot water has been made and never lights/activates.

(2)
IF the unit does activate/light immediately upon opening any hot water faucet, keep in mind that it may take 15-30 second for hot water to reach the faucet due to the length and configuration of the plumbing from the coach manufacturer. Several minutes however is way too long. Make sure that any faucet that has a showerhead, such as the outdoor shower OR the tub/shower, that both of the knobs are OFF and not ON with the showerhead button itself shut off. This will allow for mixing of hot/cold and skew the amount of hot water you'll feel at other faucets.

[Lac]

I understand Atwood tankless system are far superior to the Gerard in performance and price. Arctic Fox will not install them and Outdoors RV will not use them any more..both owned by Northwood Mfg.
The Gerard has had more customer complaints than accolades based on my forum review.

I appreciate your comments and insight,however, I respectfully disagree with your comment that the "Gerard " are excellent. This is based on my terrible Gerard experience, customer complaints,and the fact a well respected RV manufacturer are not installing them.
It's healthy to have opinions so polar opposite.
Just a question...what do you do for hot water when your on the phone to Atwood and waiting for your part?
Coops

[94-Newmar]

Lac, unfortunately, 90% of the problems people encounter with these type of units are due to something else other than the water heater itself. Just some of the issues I've had to correct from complainants include improper water flow (less than 1gpm from any faucet in the coach), outdoor shower or tub shower where both faucets are on and the showerhead is turned off, improper LPG flow rate at the water heater itself etc etc etc. On-demand whole house and single point of demand water heaters are nothing new for RVs they have been around a long time generally found on higher-end and custom busses but are now making their way to the more common RV's. In all my years I've never had one unit that I absolutely "despised" - I have not had one unit that failed more than another or had inherent problems. These things are much like mouse traps and no re-inventing is necessary behind their simplistic design.

The largest complaint is the inability to control the water temp more accurately while taking a shower. I agree, it is a problem with any on-demand unit due to fluctuating flow rates from the on-board water pump - it is not the same when connected to city water supply nor when using a conventional water storage heater. These things raise the water temp XX degrees at a certain flow rate. If you increase the flow rate you have cooler water, if you slow the rate down your output water is hotter. The easiest fix that I have done is install an accumulator tank in the system to allow for better regulation of line pressure, and replacing the original water pump with something of a much better quality. If you keep the line flow rate consistent your shower temp will be consistent.

There is much more going on behind the scenes with these things... they cannot simply be bolted in place of a conventional storage water heater and expected to be the next best thing since sliced bread.

Mass manufacturers may stay away from them since a few more and different components are required to make them work to their fullest potential - which of course means there will be more cost. There will always be debate about which is better, storage or on-demand. There will always be a market for these units and those RV'ers who's lifestyles will better accommodate one over the other.

Originally Posted by Lac

If you dry camp the endless hot water will depend on how much water you have in your water tank.

Yes, and how is this any different from a conventional storage water heater?

Originally Posted by Lac

If you use full service sites you have to use your propane as it dosen't heat by electricity.

Correct. Simply put the largest heating element that would stay within the wiring specifications for 120vac found in most coaches would be around 2200 watts (20amp).. which is nowhere near large enough to stay with the demand of raising the temps approx 50° over the input temp. Much like the RVers whom have the Hydro/AquaHot, Oasis or PrecisionTemp hydronic units.

As far as waiting for the part from Atwood, well I guess it would be the same if I was waiting for a part from Atwood on a conventional storage water heater as well.

[Lac]

I agree with everything you say,your rational,and your great explanation....that is the reason I replaced our Gerard tankless system....maybe the Atwood system is better. How we camp it's better to have a surplus of 6 gallons in my hot water tank then none at all.
Not a big issue but why should I pay for my propane to heat water when I am already paying for electricity ( that can heat water) in my daily site price..and yes we do bring an electric hot plate and use it

The tankless system advertises endless hot water...not true when dry camping....when dry camping your water capacity determines how much hot water you have. So there is not difference.

Thanks again for your insight and wisdom...I stay with what works ..until they get the bugs out.

Coops

[94-Newmar]

Originally Posted by Lac

The tankless system advertises endless hot water...not true when dry camping....when dry camping your water capacity determines how much hot water you have. So there is not difference.

Anybody that believes the advertisement of endless hot water means endless water supply should not be sharing the same oxygen as the rest of us.

Originally Posted by Lac

Thanks again for your insight and wisdom...I stay with what works ..until they get the bugs out.

Coops

....there are no bugs.... as I explained above you simply cannot put an on-demand heater in place of a water storage heater and expect the same or better performance without adding a few things to the mix....

[Lac]

Originally Posted by 94-Newmar

Anybody that believes the advertisement of endless hot water means endless water supply should not be sharing the same oxygen as the rest of us...

Don't hold your breath... "There's a sucker born every minute" by David Hannum, in criticism P. T. Barnum.

[Mr_D]

My parents had one in theie special order 1958 KenCraft TT. Worked just fine except my father didn't drain it well enough and it froze the diaphragm and broke the special shouldered two piece metric threaded screws. They were designed to do just that to protect the unit. But, trying to find replacements was a real problem as metric threads were just not common in 1958-59 era!

[Sunbeam]

I have found as the first user of hot water in the am I found that I must use the sink hot water first. It gets hot pretty quick, but if I use the shower without running the sink tap first I never get hot water. Strange phenomenon, but it works every time. I also never set the controller above 50 percent.