Hot water heater as buffer tank

[Tamarack]

The tankless hot water heater on our Nest has been a bit less than satisfying, which may also be true in other AS models?? The delay/intermittent hot water are noticeable and frustrating when trying to conserve water -- running the faucets just above a trickle. As you know the freshwater and combined grey/black tanks are small on the Nest!
So, I installed a small 2.5 gallon, 120v water heater in line with our tankless water heater. I also added an accumulator to eliminate the pump surging that we were experiencing when running the faucets at a low flow. Although I haven't field tested this yet, so far the results are very good as I've run many gallons thru the system. The hot water arrives very fast both at the kitchen sink and bathroom, even at a very low rate of flow. Also the tankless heater kicks on perfectly after a minute or two. Right now I just have the water heater plugged in externally, but plan to wire it for both shore power and inverter.
The accumulator works like a charm!
Stay tuned...

[skyguyscott]

Your idea of a fix is ingenious, ironic, brilliant, crazy, hilarious and perhaps even perfect. To fix the problems inherent in installing a tankless water heater in a small RV, you install several tanks, including a conventional RV hot water heater! Of course!

[Tamarack]

Originally Posted by skyguyscott

Your idea of a fix is ingenious, ironic, brilliant, crazy, hilarious and perhaps even perfect. To fix the problems inherent in installing a tankless water heater in a small RV, you install several tanks, including a conventional RV hot water heater! Of course!

Ok, go ahead and laugh...meanwhile, I'll be washing my hands in warm water!

[Tamarack]

All finished. I'm still surprised on how much the accumulator helped the water pump!

[love nest]

Originally Posted by Tamarack

Ok, go ahead and laugh...meanwhile, I'll be washing my hands in warm water!

I want one. You never fail to amaze me. WOW.

[B. Cole]

Originally Posted by Tamarack

Ok, go ahead and laugh...meanwhile, I'll be washing my hands in warm water!

I like it!
When the grid goes down for good,it's obvious this Glamper is going to have hot water, one way or another!
What most people don't realize, with all the new high tech stuff, is it almost insures system failure.And that's brand new.
Just sticking to these new Airstreams as an example.

[Tamarack]

Originally Posted by B. Cole

I like it!
When the grid goes down for good,it's obvious this Glamper is going to have hot water, one way or another!
What most people don't realize, with all the new high tech stuff, is it almost insures system failure.And that's brand new.
Just sticking to these new Airstreams as an example.

Thanks! Of course this is more than just the desire for a redundant hot water system, although I am a guy who definitely leans toward redundancy . I was doing some reading on the forum and see that other Airstreams with tankless systems also have "cold water sandwiching" issues - https://www.airforums.com/forums/f44...mp-217101.html

Another way of addressing this problem would be a hot water recirculation system.

[ITSNO60]

Very nice work. Will you have enough battery/inverter power to run what must be a 1,500 watt element long enough to heat 2.5 gallons of water? Also can you post some details on your accumulator, I want to build one for a swamp cooler. Did you just use a 3 or 4" piece of PVC?

edit: looking again it looks like a store bought accumulator which I hadn't considered since I didn't know they were out there.

[ROBERT CROSS]

Whatever type WH...don't waste it waiting for hot, we run it into a container and use it for rinsing, brushing teeth etc.



Bob
🇺🇸

[Tamarack]

Originally Posted by ITSNO60

Very nice work. Will you have enough battery/inverter power to run what must be a 1,500 watt element long enough to heat 2.5 gallons of water? Also can you post some details on your accumulator, I want to build one for a swamp cooler. Did you just use a 3 or 4" piece of PVC?

edit: looking again it looks like a store bought accumulator which I hadn't considered since I didn't know they were out there.

The trailer has two 120AH lithium batteries. Also, the small electric water heater is "downstream" from my tankless propane unit, so much of the incoming water will be pre-heated. I'll have more data on power consumption sometime soon.

Here's the accumulator I purchased - https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[love nest]

Originally Posted by Tamarack

The trailer has two 120AH lithium batteries. Also, the small electric water heater is "downstream" from my tankless propane unit, so much of the incoming water will be pre-heated. I'll have more data on power consumption sometime soon.

Here's the accumulator I purchased - https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

How much does your inverter pull from the batteries to run a 1500w load. This is about the same as a coffee pot.

[Tamarack]

Originally Posted by love nest

How much does your inverter pull from the batteries to run a 1500w load. This is about the same as a coffee pot.

Good comparison, although it would be a coffee pot that turns on and off all day

[Tamarack]

Originally Posted by love nest

How much does your inverter pull from the batteries to run a 1500w load.

Here's what it pulls when I first turn it on. It heated up in about 15 minutes. The tank seems to keep the water hot very well. Of course, if I use any amount of hot water the propane tankless heater kicks on and replenishes with hot water so it turns off sooner. I tested the system in several ways and so far it has disappointed me. Seem to work great, though I'm still in the process of testing different scenarios.

[dznf0g]

Originally Posted by ROBERT CROSS

Whatever type WH...don't waste it waiting for hot, we run it into a container and use it for rinsing, brushing teeth etc.



Bob
[emoji631]

Or install one of these:

https://tweetys.com/aqua-viewsmz001....hoCbF4QAvD_BwE

[Tamarack]

Originally Posted by Tamarack

Here's what it pulls when I first turn it on. It heated up in about 15 minutes. The tank seems to keep the water hot very well. Of course, if I use any amount of hot water the propane tankless heater kicks on and replenishes with hot water so it turns off sooner. I tested the system in several ways and so far it has disappointed me. Seem to work great, though I'm still in the process of testing different scenarios.

...I forgot to mention that this setup has completely eliminated the problems I had with getting hot water at low flow levels as well as the cold water blast I used to get when I turned the water off, and then on again .

[love nest]

Originally Posted by Tamarack

Here's what it pulls when I first turn it on. It heated up in about 15 minutes. The tank seems to keep the water hot very well. Of course, if I use any amount of hot water the propane tankless heater kicks on and replenishes with hot water so it turns off sooner. I tested the system in several ways and so far it has disappointed me. Seem to work great, though I'm still in the process of testing different scenarios.

Thanks for the info. Now I see the problem with My BMS on my battery Rated at 100 amps. People say it will do up to 130 but I would not like to count on that. Was that a misprint where you said you were disappointed with your water heater setup.

[Tamarack]

Originally Posted by love nest

Was that a misprint where you said you were disappointed with your water heater setup.

Yes, mean say that it "hasn't disappointed me"

[love nest]

Originally Posted by dznf0g

Or install one of these:

https://tweetys.com/aqua-viewsmz001....hoCbF4QAvD_BwE

This one looks promising: https://aquaviewinc.com/product/skb0...rushed-nickel/

[panamerican]

I think this is a great solution to a problem Airstream itself is responsible for creating.

I find it completely deplorable that a customer has to do anything close to this on a new(er) unit. How Airstream could possibly think their solution was a good idea is beyond me.

For boondockers, throw in a 12v frigde and you've basically committed folks to bringing generators and many additional gallons of water.

Sorry, just venting here when I see a customer that spent between $30k -$40k and has to do what Airstream should solved long before offering these poorly thought water heating and fridges as standard equipment.

[mythbuster88]

Really nice upgrade!