Thoughts on freshwater tank size size

[SteveJ]

Originally Posted by avanti

On units that can be shut off at the shower head, the dribble is deliberate. It is a safety feature to avoid scalding when hot water is forced into the cold line when the shut-off is closed.

That's why I use a meat thermometer attached to the water heater to bring the temp of the water just up to my preferred shower temp and run the shower water from the hot water heater only for a shower. This way I don't waste water blending for the right temp and I don't have to worry about dribbling and wasting more water to prevent a scalding/freezing issue from completely shutting off the shower head.

[avanti]

Originally Posted by SteveJ

That's why I use a meat thermometer attached to the water heater to bring the temp of the water just up to my preferred shower temp and run the shower water from the hot water heater only for a shower. This way I don't waste water blending for the right temp and I don't have to worry about dribbling and wasting more water to prevent a scalding/freezing issue from completely shutting off the shower head.

Yes.
You can do the same thing automatically by adding a tempering valve to your water heater. My Rixen's flash-plate heat exchanger hydronic system has to have one, else it would produce dangerously hot water.

[Davydd]

Originally Posted by rockymtnb

That is impressive water efficiency. Have you found a showerhead that works well for Class B water conservation? The RV oriented ones we've found either dribble water, have inefficient spray patterns, or don't have a good push trigger to get a quick burst of water and then shut back down completely.

My shower head doesn’t dribble. There is separate hot/cold water adjustment Knob and then a trigger lever Handle similar to a garden hose with quick burst which can be controlled better than the awkward push button types my two previous vans had with the dribble.

[rockymtnb]

Originally Posted by avanti

On units that can be shut off at the shower head, the dribble is deliberate. It is a safety feature to avoid scalding when hot water is forced into the cold line when the shut-off is closed.

On our current unit we set the water heater at 105 deg F and use only the hot water supply for showers. However our new unit will have the Truma AquaGo and apparently cannot be set below 120 F. So we'll probably need to use the tempering valve and backflow check valve combination to achieve 100% hot supply showering and shutoff.

I'd much rather have a lower temperature hot water supply for showering than deal with dribble and drool water wasting showerheads.

[rockymtnb]

Originally Posted by Davydd

My shower head doesn’t dribble. There is separate hot/cold water adjustment Knob and then a trigger lever Handle similar to a garden hose with quick burst which can be controlled better than the awkward push button types my two previous vans had with the dribble..

That trigger style handle looks like the right approach. Any idea what brand it is?

[GeorgeRa]

Originally Posted by avanti

Yes.
You can do the same thing automatically by adding a tempering valve to your water heater. My Rixen's flash-plate heat exchanger hydronic system has to have one, else it would produce dangerously hot water.

...............

My Isotemp marine water heater came with built in a tempering valve.

[SteveJ]

Originally Posted by avanti

Yes.
You can do the same thing automatically by adding a tempering valve to your water heater. My Rixen's flash-plate heat exchanger hydronic system has to have one, else it would produce dangerously hot water.

Agreed, sort of. I would want the tempering valve at the shower faucet so as not to restrict the entire system. Either way gets into a somewhat difficult install on our unit due to space constraints.

The meat thermometer is just too easy to use vs the hassle of mounting a tempering valve.

I can see an advantage, though, to make more shower water available but we can back to back shower on a single heating of the 6 gal Suburban hot water tank.

[Davydd]

Originally Posted by rockymtnb

That trigger style handle looks like the right approach. Any idea what brand it is?

Scandvik. They seem to be a Florida company focusing on boating products. This is a standard installation for Advanced RV as I don't recall a Class B without one.

[avanti]

Originally Posted by Davydd

Scandvik. They seem to be a Florida company focusing on boating products. This is a standard installation for Advanced RV as I don't recall a Class B without one.

Yes, but I'm sure that ARV also uses a tempering valve. The point is that there is a scalding risk unless you either have a dribbling fixture or else some way to limit the heater output to a safe level. Obviously, the latter is the way to go.

[Davydd]

Originally Posted by avanti

Yes, but I'm sure that ARV also uses a tempering valve. The point is that there is a scalding risk unless you either have a dribbling fixture or else some way to limit the heater output to a safe level. Obviously, the latter is the way to go.

Don't you see the hot/cold water valve right above the spray head in that cabinet photo I posted? That's direct control no different than a home shower. No dribble necessary.

[avanti]

Originally Posted by Davydd

Don't you see the hot/cold water valve right above the spray head in that cabinet photo I posted? That's direct control no different than a home shower. No dribble necessary.

For many years now, single-knob valves such as that have been required by code to contain an integral tempering mechanism.

[GeorgeRa]

My hot water system has two temperatures controls, first is the antiscald automatic valve, a tempering valve and the second are final use temperature adjustment valves at the shower head and the sink faucet.

If hot water heater has temperature adjustment to be below or at 120 F than antiscald valve is not needed. In case of marine water heaters where water can reach over 200F (engine oil temperature) these valves are necessary for safety.

Hydronic system can reach 175F so tempering valves are also needed. I am sure all Rixen system have a tempering valve just like Isotemp or other marine heaters.

I am not sure what is the advantage of heating water to shower temperature using auxiliary thermometer if a water heater maintains water at or below scalding 120F. At home my on-demand heater is set for 120F.

[SteveJ]

Originally Posted by GeorgeRa

I am not sure what is the advantage of heating water to shower temperature using auxiliary thermometer if a water heater maintains water at or below scalding 120F. At home my on-demand heater is set for 120F.

From my earlier posts:

That's why I use a meat thermometer attached to the water heater to bring the temp of the water just up to my preferred shower temp and run the shower water from the hot water heater only for a shower. This way I don't waste water blending for the right temp and I don't have to worry about dribbling and wasting more water to prevent a scalding/freezing issue from completely shutting off the shower head.

And:

Agreed, sort of. I would want the tempering valve at the shower faucet so as not to restrict the entire system. Either way gets into a somewhat difficult install on our unit due to space constraints.

The meat thermometer is just too easy to use vs the hassle of mounting a tempering valve.

I can see an advantage, though, to make more shower water available but we can back to back shower on a single heating of the 6 gal Suburban hot water tank.

[GeorgeRa]

Originally Posted by SteveJ

From my earlier posts:

That's why I use a meat thermometer attached to the water heater to bring the temp of the water just up to my preferred shower temp and run the shower water from the hot water heater only for a shower. This way I don't waste water blending for the right temp and I don't have to worry about dribbling and wasting more water to prevent a scalding/freezing issue from completely shutting off the shower head.

And:

Agreed, sort of. I would want the tempering valve at the shower faucet so as not to restrict the entire system. Either way gets into a somewhat difficult install on our unit due to space constraints.

The meat thermometer is just too easy to use vs the hassle of mounting a tempering valve.

I can see an advantage, though, to make more shower water available but we can back to back shower on a single heating of the 6 gal Suburban hot water tank.

My question relates to wasting water, why would volume / shower change by using shower temperature water from a water heater tank only or by mixing hot with cold. Let’s assume you need 4 gal. for shower and you take it directly from a water heater tank at shower temperature the water pump will replenish this used water with cold water instantly.

[rockymtnb]

Originally Posted by rockymtnb

That trigger style handle looks like the right approach. Any idea what brand it is?

Originally Posted by Davydd

Scandvik. They seem to be a Florida company focusing on boating products. This is a standard installation for Advanced RV.

Checking Scandvik's website it turns out that trigger showerhead is available as an aftermarket part #14004. Amazon has it for $20 in white (or $33 fake chrome).

https://www.amazon.com/Scandvik-1400...0533750&sr=8-1

To call this is a good RV showerhead would be a vast understatement. It's got a strong and well directed spray pattern and gives a quick burst when triggered but shuts off completely when released. Not even a speck of drool and dribble.

Can't believe we went seven years trying at least that many crappy showerheads, including the much-touted Oxygenics drooler, before finding this perfect one. And of course it's right before selling our current van, but at least the new owners get a great showerhead, and we know which one to add to our new van.

Figures that ARV would go to the marine and yacht world to get the best products. Thank you David for that referral.

[Davydd]

You're welcome and thanks, rockymtnb. It's been 8 years now for ARV (5 years for us) and I can't believe others have not picked it up and people are still discussing dribble theory.

[avanti]

Originally Posted by Davydd

I can't believe others have not picked it up and people are still discussing dribble theory.

As we have discussed, such a fixture would be dangerous without a properly set tempering valve. That adds $100 to the cost of the plumbing. No problem for ARV, but a significant amount for some upfitters.

Do any of the new "combi" units provide for temperature limiting?

[rockymtnb]

Originally Posted by avanti

As we have discussed, such a fixture would be dangerous without a properly set tempering valve. That adds $100 to the cost of the plumbing. No problem for ARV, but a significant amount for some upfitters. Do any of the new "combi" units provide for temperature limiting?

Our Sportsmobile didn't have a tempering valve so we just set the water heater to a comfortable shower temperature, which turned out to be about 105 F, then take showers entirely from the hot water supply. No scalding or temperature variations and the flow can be stopped completely for soaping and scrubbing.

Truma Combi has an Eco water temperature setting at 40° C / 104° F that would likely suffice on many modern Class B vans.

[Bud]

Originally Posted by Davydd

You're welcome and thanks, rockymtnb. It's been 8 years now for ARV (5 years for us) and I can't believe others have not picked it up and people are still discussing dribble theory.

I went with one of the nice shower-heads about 12-13 years ago. Mine is called a sink sprayer.

[Davydd]

Originally Posted by avanti

As we have discussed, such a fixture would be dangerous without a properly set tempering valve. That adds $100 to the cost of the plumbing. No problem for ARV, but a significant amount for some upfitters.

Do any of the new "combi" units provide for temperature limiting?

Temperature limiting is the same with your kitchen and bathroom sink, an adjustable combination of hot and cold water valve. With a short burst you can test it in your hand over the sink if you want but knowing how to adjust and use same as washing your hands it may never come to that.

The sprayer is way, way more efficient in conserving water in a Class B.