On demand hot water heater

[Geo4]

I have a 22 four winds 31w class c It takes having to run the water a long time to get hot water to the kitchen sink In Fla now and temps morning and night cold Therefore water coming in to coach is cold Could that be why water takes so long to get hot Would heated water hose help Thx

[EA37TS]

Nature of the beast. That’s why Seneca peers installed a water circulation system to get the water warm before it is needed.

[vegasruv24.1]

Originally Posted by Geo4

I have a 22 four winds 31w class c It takes having to run the water a long time to get hot water to the kitchen sink In Fla now and temps morning and night cold Therefore water coming in to coach is cold Could that be why water takes so long to get hot Would heated water hose help Thx

I learned this the hard way,... when taking a shower, you can't turn the water off,... or it comes out freezing again... they seem to waist a lot of water because they always have cold water in the lines.... the way I used to do it was always use the hot side so you don't have to run the water so long to get hot water, and when shoewering,.. get wet soap up and turn the water back on to rinse.... the on demands shut the heat off when you shut off the water , so when you turn it back on cold water comes out....freezing cold water...

[Bob Nodine]

Originally Posted by Geo4

I have a 22 four winds 31w class c It takes having to run the water a long time to get hot water to the kitchen sink In Fla now and temps morning and night cold Therefore water coming in to coach is cold Could that be why water takes so long to get hot Would heated water hose help Thx

You need to run the hot water only and leave it running while you take a shower. Also, if you have the temperature set very low you may have the same issue because the water heater control may shut off the heat in an attempt to keep the temp at your low setpoint. It is best to have the temp around 100 to 110 degrees and mix in a little cold if that is to hot for a comfortable shower. I know that sounds like a waste of water but that is the nature of an on-demand water heater. They are not very compatible to a Navy shower or dry camping without hookups.

[DavidEM]

As noted it is the nature of the beast. Make sure you turn the hot water off quickly to minimize the slug of hot cold water if you turn back on. I just leave it on all of the time and yes that wastes some water.

FWIW, circulating hot water systems won’t work with on demand hot water.

The Girard on demand hot water heater is one of the two love/hate relationships I have with my 2021 Axis. The other is the BMPro display/controller.

David

[Judge]

Water Flow is critical for proper operation of the Girard. First, you need adequate pressure. If you have a regulator installed on the City Water outlet (as you should) you need 50PSI +/- 5PSI. If the campground has low pressure, there is nothing you can do except use your fresh water tank for showers.

Next, you should remove all of your strainers / screen / flow restrictors from every faucet (including the shower head) and clean them. Often there is construction debris in the water lines that will build up on the screens and slow flow. remove them all and then run the water to clear the lines before reinstalling them.

Finally, when ground water temps are cold to very cold, you may have to adjust the flow valve on the back of the unit to slightly slow the flow so the water stays in the heat exchanger longer.

[EA37TS]

Originally Posted by DavidEM

…

FWIW, circulating hot water systems won’t work with on demand hot water.

David

Yes they do. The water is circulated through the system and then instead of coming out a faucet it is dumped back into the fresh water tank so it is not wasted, especially when boondocking.

The Seneca folks didn’t use some POS off the shelf system, the designed and installed their own.

But, then again, nobody except the self proclaimed Thor experts know anything.

Here is a link to include YouTube video from someone who has done this.

https://www.jaycoowners.com/forums/f...ion-67344.html

[DavidEM]

Well, yes they can work but it means that the hot water flow would have to be wide open, not a small low volume circulating pump. Maybe set it up for a minute or two on and 5-10 minutes off.

David

[16ACE27]

Originally Posted by DavidEM

Well, yes they can work but it means that the hot water flow would have to be wide open, not a small low volume circulating pump. Maybe set it up for a minute or two on and 5-10 minutes off.

David

The systems don't use a recirculating pump like a home "always hot" system does. They just return cold water to the onboard tank until the water to the shower is hot.

[JimOIB]

An alternative that I use is a 2 gallon food grade bucket and recapture the cold shower water until it gets hot. From there I either wash my dishes with the tepid water or boil and store it to make coffee in the morning/refill water bottles. In the water/propane balance equation I run out of water far faster than propane - buys me 2 more days off the grid.

[Chateau_Nomad]

Recent video reviews of new motorhomes show a trend to returning to tank water heaters. Tankless has a certain appeal for some, but for our camping style it would definitely be a headache. Like the touch panel controls, they're fun... until they stop working.

[16ACE27]

Originally Posted by Chateau_Nomad

Recent video reviews of new motorhomes show a trend to returning to tank water heaters. Tankless has a certain appeal for some, but for our camping style it would definitely be a headache. Like the touch panel controls, they're fun... until they stop working.

Exactly! What value does that fancy touchscreen/bluetooth/app really bring to using the RV? I'll settle for independent switch controls any day.

[DavidEM]

Originally Posted by 16ACE27

Exactly! What value does that fancy touchscreen/bluetooth/app really bring to using the RV? I'll settle for independent switch controls any day.

First let me apologize for hijacking this thread:

The fancy BMPro touchscreen device and separate Node does save a lot of wiring and switches. My Axis has just 7 device switches- four in the bedroom, two in the head and one on the dash. Everything else is controlled by the BMPro- lights, generator start/stop and AGS, slides, A/C and furnace thermostat. To do this witch switches and other devices would take a bunch of switches, a thermostat, an AGS, etc. The BMPro does it all.

With the BMPro, a couple of 15A circuits provide power to the Node which controls everything. The wire to the device goes directly to the device, not to a switch nearby on the wall and then to the device. That saves a bunch of wiring and a bunch of switches and other devices.

But all in all, I am with you- give me simple switches.

David

[EA37TS]

Originally Posted by DavidEM

Well, yes they can work but it means that the hot water flow would have to be wide open, not a small low volume circulating pump. Maybe set it up for a minute or two on and 5-10 minutes off.

David

Most use an electronic valve on the hot water side and use the rig’s water pump to dump cold water in the hot water lines into the fresh water tank which in turn fires up the hour water heater. Depending on who did the setup their system is operated by timer or on/off switch. These are not out of the box mass produced recirculating systems. They are RV owner engineered and installed systems done by some pretty smart people.

[Chateau_Nomad]

In a residential setting I understand the intent of thankless... endless hot water and only heated when it's needed.

That's great in an RV too when you have an endless supply of water. But what happens when you don't? Seems the trade-offs outweigh the benefits when you only have 40 gallons of water and a 6 gallon water heater.

[EA37TS]

Originally Posted by Chateau_Nomad

In a residential setting I understand the intent of thankless... endless hot water and only heated when it's needed.

That's great in an RV too when you have an endless supply of water. But what happens when you don't? Seems the trade-offs outweigh the benefits when you only have 40 gallons of water and a 6 gallon water heater.

You might try reading the thread. Talking about

Tankless water heater taking too long to heat water
Water waste while waiting for hot water
Recirculating back to fresh water tank to minimize wasted water not yet hot.

[Chateau_Nomad]

Originally Posted by EA37TS

You might try reading the thread. Talking about

Tankless water heater taking too long to heat water
Water waste while waiting for hot water
Recirculating back to fresh water tank to minimize wasted water not yet hot.

Yep I've heard all that. So... with a tankless requiring fairly robust water flow, how to control water use when the faucet must be fully open? For those with full hookups, how would dumping unheated water into the fresh tank work? What happens when the tank is full?

Our situation may be unique, but we've never had an issue with lack of hot water from our 6 gallon tank. Granted, it's NOT endless, AND we take navy showers. My plan is to eventually install a recirculation setup, which solves the cold water issue.

So what am I missing? What is the major benefit of an RV tankless water heater... with someone doing a mix of boondocking and campgrounds with hookups?

[DavidEM]

Originally Posted by Chateau_Nomad

So what am I missing? What is the major benefit of an RV tankless water heater... with someone doing a mix of boondocking and campgrounds with hookups?

Advantages:

If the propane or power supply has been off you don’t have to wait 20 minutes to get hot water.

No bypass valves are required for winterization.

No corrosion protection anode.

Disadvantages:

You can’t easily adjust water temp while showering.

Hot water valve must always be wide open when using.

Can’t turn hot water off without getting a slug of cold water when you turn it back on.

AFAIAC the pluses and minuses are about equal, maybe favoring the pluses.

David

[wrapped]

Aqua View Showermiser : part # SMB001 - $59.95. Google it. 4hrs 30ft pex pipe and a couple shark bite fittings.

Now you can take navy showers.
No wasting water or filling grey tank when boondocking.
You can fill fresh water tank when hooked to city water by flipping the valve with out going outside.

PS if low water pressure in campground just turn on your water pump it will boost pressure enough for hot water.

LETS NOT MAKE THIS MORE COMPLICATED THAN IT REALLY IS.

[Judge]

Originally Posted by Chateau_Nomad

That's great in an RV too when you have an endless supply of water. But what happens when you don't? Seems the trade-offs outweigh the benefits when you only have 40 gallons of water and a 6 gallon water heater.

I have a 60 Gallon Fresh and 40 Gallon Holding Tanks I have boondocked 4 days with my Girard tankless. Took showers and washed dishes as we normally do on city water. When you are using the onboard pump, the tankless well.