Better shower?

One of my first spring projects is to replace the stock shower with a new Oxygenics head.  While I'm at it, what would eliminate the temperature shift when stopping and starting the shower.  A new faucet?

Check valves in the shower feed lines usually helps. If the water is always hotter for a few seconds on a restart, a check valve in the cold line will work, or the hot line if the water is always cold. If it varies, do both. The problem comes from one line having slightly more pressure than the other, so when you shut off the water at the shower head, the higher pressure line backfeeds into the other line a bit through the mixer valve.

I don't see a part like that on CW site.  Where do you find those?

NY_Dutch said:

The problem comes from one line having slightly more pressure than the other, so when you shut off the water at the shower head, the higher pressure line backfeeds into the other line a bit through the mixer valve.

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Dutch, I guess you'll need to explain that a little. The way I've always seen it, if let's say the pump shuts off at 40 PSI pressure or the shore power water has 40 PSI pressure, how does one line get a higher pressure than another one? The entire system should be 40 PSI pressure no matter which faucet you open.

what would eliminate the temperature shift when stopping and starting the shower.

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Most RV showerheads are attached to the wall but come off for use as a handheld showerhead.  The part you hold in your hand might have either a lever or a push button to turn the water off.  In theory that mitigates the changes in water temperature and eliminates the need to turn it off the faucet.  I don't know if the Oxygenics showerhead has such a lever but it's something RVers need for conserving water when taking "navy" showers such as when boondocking.

ArdraF

ArdraF said:

Most RV showerheads are attached to the wall but come off for use as a handheld showerhead.  The part you hold in your hand might have either a lever or a push button to turn the water off.  In theory that mitigates the changes in water temperature and eliminates the need to turn it off the faucet.  I don't know if the Oxygenics showerhead has such a lever but it's something RVers need for conserving water when taking "navy" showers such as when boondocking.

ArdraF

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This one does have a shut off. Don't know if they all do.  http://www.amazon.com/ETL-26181-Chrome-Oxygenics-Shower/dp/B00F5MU5YY/ref=sr_1_2?ie=UTF8&qid=1452483722&sr=8-2&keywords=rv+shower+heads+oxygenics

Rene,,

You might want to proofread your post (Reply #5).  ;D

R

When I bought my Oxygenics a few years ago it didn't have the off on button so I went to Home Depot and go one for around $5.

Rene T said:

Dutch, I guess you'll need to explain that a little. The way I've always seen it, if let's say the pump shuts off at 40 PSI pressure or the shore power water has 40 PSI pressure, how does one line get a higher pressure than another one? The entire system should be 40 PSI pressure no matter which faucet you open.

Click to expand...

Different line lengths with different expansion characteristics allows the line with less expansion to force water into the other line through the open mixer valve. The pressure in both lines doesn't equalize until the longer line balances with the shorter line.

Temp shift in the shower is pretty common so don't assume you have a problem right off until you use it for a bit. The temp shift comes from a safety so you don't scald yourself when turning on the water in the shower. The trick is to turn on the shower and set the temp with the knobs on the wall and then turn off the shower with the knob on the shower head itself while you soap up etc. This helps but is not foolproof. The oxegenics shower head does have a shut off right on the head, we use one. Set the temp with your knobs on the wall, then shut off the water with the shower head so you don't have to touch the knobs on the wall. When you are ready to rinse turn the shower head away from yourself and turn it on to let the water temp stabilize in a couple secs. When you finish with the shower shut off the knobs on the wall and leave the shower head turned on so it will drain. 
First off do yourself a favor and supply the MH with a 5/8 dia water hose and a decent regulator (not the $12 cheapee reg that is sold in most CG stores). When you take a shower we always turn on the water pump even when hooked to CG water. This way if the CG water psi drops below the water pump setting in the MH, the pump boosts psi from the onboard water tank so we have a constant flow/pressure to the shower.
Second turn on the gas water heater. I know you have the electric water heater going since you are plugged in but the gas heater along with the electric will help you recover hot water faster.
If you are the only one in the MH these suggestions might not be that important. If you are taking a shower when others are flushing the toilet and washing dishes these will become very important. Good luck with it.

In our last MH the shower was way too small for me to fit in...Really made taking a shower a hassle. With the tight stall we had the Oxagenics shower head. We liked the way to water swireled out BUT the button for shutoff I could do with out. Seems I was always hitting that darn thing while rinsing off the nooks and crannys...Got rid of it and found one that didn't have the head shutoff button. The Class A we have now is much improved with a man size shower...all is well once again

Its not so much 'pressure' as flow rate. Pressure is measured when there is no flow- its static pressure which is measured by the pressure regulator.

What you have issues is with is flow rate. Since the cold water pipes are generally shorter between shore water and the shower, thus they have less elbows and length of pipe to run through making less resistance to the flow of water, resulting in a higher flow rate. The hot water pipes are generally longer as the water loops from the pressure regulator, to the HWH, then back to the shower. That adds more pipe and more elbows which reduces flow rate. Unless you re-pipe the hot and cold with exactly the same length of pipe and number of elbows, you will experience some level of flow rate between the hot and cold supplies (assuming a single source of water AKA the same pressure on the hot and cold incoming line)

You can buy a thermostatic valve. These valves have temperature sensitive internal hot and cold valves which regulate the volume of incoming hot and cold water. If you use up all the cold water setting in the pipes, then start using much colder well water, the thermostatic valve will automatically adjust the incoming cold water to compensate. The same is true for the hot side. If you start to run the HWH past capacity, the thermostatic valve will control the incoming hot water to compensate. Thermostatic valves operate by the temperature of the water alone and need no other source of power to operate. Simply set the temperature setting where you like it and open the diverter to start the flow.

http://www.rvtravel.com/?q=daily-rv-tips-issue140971

The Grohe valves are $386 on Amazon


http://smile.amazon.com/Grohe-34182000-Grohtherm-Exposed-Thermostatic/dp/B003U4Q1SI/ref=sr_1_sc_1?ie=UTF8&qid=1452490287&sr=8-1-spell&keywords=grohe+geotherm+3000

RLSharp said:

Rene,,

You might want to proofread your post (Reply #5).  ;D

R

Click to expand...

OOPS!!!! ;D  Thanks.

Houston Remodeler said:

Its not so much 'pressure' as flow rate. Pressure is measured when there is no flow- its static pressure which is measured by the pressure regulator.

What you have issues is with is flow rate. Since the cold water pipes are generally shorter between shore water and the shower, thus they have less elbows and length of pipe to run through making less resistance to the flow of water, resulting in a higher flow rate. The hot water pipes are generally longer as the water loops from the pressure regulator, to the HWH, then back to the shower. That adds more pipe and more elbows which reduces flow rate. Unless you re-pipe the hot and cold with exactly the same length of pipe and number of elbows, you will experience some level of flow rate between the hot and cold supplies (assuming a single source of water AKA the same pressure on the hot and cold incoming line)

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Now that makes sense to me. I just couldn't see the reply that said the lines had different pressure.

The Oxygenics "RV Spa" model has a valve they call "Smart Pause". It allows water to trickle out when limiting the flow and keeps the water at the same temp. Ours works great. Found Amazon had the lowest price when we bought ours.

When the valve at the shower handle is shut off, a circulation loop is created. Hot water rises, cold water subsides, and hot water moves in to the cold water line, the same reason older hot water heating systems without pumps worked.

The longer the valve remains closed, the longer it takes to get that hot water out of the cold water line, and the longer the blast of too hot water. will be.

At least that is my theory.  ;D

OLDRACER said:

When the valve at the shower handle is shut off, a circulation loop is created. Hot water rises, cold water subsides, and hot water moves in to the cold water line, the same reason older hot water heating systems without pumps worked.

The longer the valve remains closed, the longer it takes to get that hot water out of the cold water line, and the longer the blast of too hot water. will be.

At least that is my theory.  ;D

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Good theory but mine is just the opposite. I get  short blast of cold water when I open up the valve on the shower head.  ??? :

Rene T said:

Now that makes sense to me. I just couldn't see the reply that said the lines had different pressure.

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In addition water expands when heated and the hot water line will see an increase in volume/pressure over the cold water line because of the temperature difference.


Winnebago even puts a check valve in the water heater cold water input line to prevent the hot water from backing up into the cold water line. (they also have one in the output line as part of the single valve winterizing system)

kdbgoat said:

The Oxygenics "RV Spa" model has a valve they call "Smart Pause". It allows water to trickle out when limiting the flow and keeps the water at the same temp. Ours works great. Found Amazon had the lowest price when we bought ours.

Click to expand...

Yes, I actually found taht this feature basically eliminated the temperature swing problem I was having.  At first I was conscerned about wasting water while boon docking and filling up my tank too fast.... but it's really a very small flow rate and I think I actually save quite a bit of water with this thing

It fixed my temperature problem, maybe you'll have similar luck