Community Forums

CountryB · 09-09-2019, 08:24 AM

I'm just doing a pre-trip inspection and testing all my systems.

I turned on the Aqua-Hot (Diesel mode) and it fired right up, but it seemed to take a long time before hot water started coming out of kitchen faucet. I let it run for a "few minutes" then it started to feel warm (I didn't run the faucet until the water was hot).

So how long should it take the Aqua-Hot to get hot water to kitchen sink? I'm in Florida so the temperature of the water in my fresh water tank is probably 75-80 degrees to start with.

And if I'm camping without using the Aqua-Hot "electric mode" am I gong to need to wait a couple of minutes every time I want hot water? I thought the Aqua-Hot was supposed to be near instant hot water (maybe I'm thinking of those on-demand hot water systems for home use, and the Aqua-Hot is different).

Spk64 · 09-09-2019, 08:36 AM

It takes 5-10 minutes to get the water hot if starting first time with burner. Unlimited hot water is what they are good for. We leave the electric elements on and fire up burner when needing more hot water.

Solo_RV_Guy · 09-09-2019, 08:40 AM

Quote:

Originally Posted by CountryB

I'm just doing a pre-trip inspection and testing all my systems.

I turned on the Aqua-Hot (Diesel mode) and it fired right up, but it seemed to take a long time before hot water started coming out of kitchen faucet. I let it run for a "few minutes" then it started to feel warm (I didn't run the faucet until the water was hot).

So how long should it take the Aqua-Hot to get hot water to kitchen sink? I'm in Florida so the temperature of the water in my fresh water tank is probably 75-80 degrees to start with.

And if I'm camping without using the Aqua-Hot "electric mode" am I gong to need to wait a couple of minutes every time I want hot water? I thought the Aqua-Hot was supposed to be near instant hot water (maybe I'm thinking of those on-demand hot water systems for home use, and the Aqua-Hot is different).

On diesel you shouldn't need more than a few miutes. It's not instant but it's fast.

Is the exhaust from the AH unit sooty? Do the status lights on the unit indicate proper operation?

CountryB · 09-09-2019, 08:42 AM

Thanks Steve.

I'm not sure if I should leave the electric element on or not while camping, if I only have 30 Amp Shore Power. With one or two roof AC units running I may not have enough shore power to also run the hot water electric element too.

I guess I can find out.
It's not too hard to reset the Shore Power breaker if I overload it.

CountryB · 09-09-2019, 08:44 AM

The exhaust is good. Starts out looking a little white-ish, then clears up after a minute or two. All status lights are green.

RamiDav · 09-09-2019, 09:50 AM

Mike ,
As for waiting , our Aqua Hot is just another water heater the
water still has to flow to the faucets
When boondocking its a waste of water and grey tank space
I have wanted to do something for a while so I don't have to wait
for hot water
A circulating pump similar to those used in homes could probably
do the job .
I have thought about putting a 12v pump at the shower with a sw so
I can better stabilize the temp while turning the water off and on .
The same pump could be routed to have hot water always at the
kitchen faucet too I suppose .
Ray

96 Wideglide · 09-09-2019, 09:52 AM

It's only 'on demand' if your boiler tank is already up to temp.

From a cold boiler tank, with mild outdoor temps, mine will reach cut-out temp in just under 10 min.

RustyTools · 09-09-2019, 10:00 AM

It could be you're asking two separate questions. 1) How long before the Aqua-hot 'makes' hot water, or 2) How long does it take for already-hot water from the Aqua-hot to get to your tap(s)?

Mine gets hot on diesel in about 10 minutes, and somewhat longer when on electric. I leave it on electric all the time, unless there's a big power draw (both AC's, microwave, and hair-dryer, that kind of stuff).

We're in the Keys, so our 'cold' is never cold, but I do like Ray's idea of a recirculation system. If you do it, Ray, please post your thoughts/results.

Mr_D · 09-09-2019, 10:09 AM

My 600D unit takes about 20 min to heat water using
the diesel. I usually only turn on one electric element since each is 2000 watts. For showers I turn on the burner.

kenwyatt · 09-09-2019, 10:28 AM

Country, your set up is the same I believe, 7.5 kw. On 30 amp with what you mentioned as far as AC’s I believe you will overload the breaker. Last time I checked mine it was 34 amps at the heating element

distaff · 09-09-2019, 11:01 AM

Mike,

The AH process is first it fires the burner, heats the combustion chamber, then heats the boiler shroud, then heats the boiler fluid, then heat soaks the water tubes.

About 10 minutes seems right. If I'm off grid or on limited power I fire it when I get up and leave it on until we have showered and done any laundry or dishes. Then I leave it off for most of the day and it still has heat for warm water for hand washing.

Come dinner we fire it again about the time we start clearing up. The other point is that if you are not drawing any heat leaving it on all day will result in only a few short firings and won't burn too much fuel.

On limited shore power I will leave the electric AH on if it isn't not enough to call for AC since we don't use that much other power.

CountryB · 09-09-2019, 11:05 AM

My unit is the AHE-100-04S.
The manual says the electric element is 1650 Watts (1.65kW).

It has a 30A circuit breaker in the panel (according the wiring diagram. I'm not near coach now to confirm). That breaker is twice the size needed - if my math is correct: 1650W / 120V = 13.75A.

So if I round up, 15A for the water heater, and the Dometic AC unit needs 15.3A (compressor-locked rotor amps is 63A if that matters), I should be able to run the electric water heater and one AC unit on a 30 Amp service, with a little power to spare for the TV.

96 Wideglide · 09-09-2019, 02:14 PM

Sounds about right, although if you leave your battery charger or fridge on elec, it will likely put you over the top.
Can't say I've ever tried running AH on elec, and a heatpump at the same time on 30A.

CountryB · 09-09-2019, 02:28 PM

I think your right. I'll leave the electric water heater off and just fire up the diesel burner when hot water will be needed (showering or dishes, etc.) which wont be that often anyways.

No need to waste power keeping the water hot for 23 hours a day when I'll only use it for 30 minutes in the morning and 30 minutes at night.