professor95
Mechanicsville, VA
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RJsfishin wrote:I didn't misunderstand when I made my earlier post.
But Sam said it much better,...in that he mentioned the dribble shutoff that all 3 of my RVs have had also.
Again, w/ this type of shutoff, I too have never had the hot/cold problem that seems to be common in some RVs. And changing the shower head to the dribble type, would seem a much easier, faster, and less expensive way to solve the problem.
Right, and some RVs will NOT have the problem because of the way their plumbing was installed to begin with. It all will depend on the distance from the cold water inlet and the hot water outlet in relationship to the shower. If the pipes are close to or equal distances, there should be no problem.
Professor Randy T. Agee & Nancy Agee, Mechanicsville, VA
2009 Cedar Creek 34SATS 5th Wheel - GMC 3500 dually
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professor95
Mechanicsville, VA
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A week ago I knew little or nothing about check valves other than their purpose. Now that I have bought and installed two, I am discovering additional information that I did not have when I made the shower mod.
First, your RV most likely has a check valve in the city water connection. It can be built into the connector or just after as an in-line valve. If you do not have this check valve or it is bad, you will get a pretty good rush of water from the camper side of your city connection when you disconnect. Your camper water pump will pump water out of an open city water connection if the check valve is bad.
You also have a check valve in the cold water line that is common to the water pump outlet and city water hook up. This is installed to keep water from the city water side from flowing into the pump and possibly causing damage or backflowing into your water storage tank.
These check valves seem to hold up pretty good. I asked the shop forman at the dealership I use about them and he said that they occasionally replace one, but not very often. Thus, their durability appears to be OK.
The check valves from an RV dealer should not cost any more than the small plastic ones from Lowe's. The valves from the RV dealer will be brass vs. plastic from Lowe's. The RV type valves are available with 1/2" male threads on each end or male on one end and female on the other. This may help reduce the use of adapters if you do the mod. RV dealerships should also carry the PEX slip on repair fittings like the ones I used. The catalog shows a PEX coupler that will fit female 1/2" and another that will fit male 1/2" for about the same price as I paid at Lowe's.
The big fat valves I used from Lowe's are constructed different inside (which is why they are fat). IMHO, the construction of the fat valve appears to be superior to the "normal" valve used on RVs and very possibly will last longer and give less trouble. Of course, this all remains to be seen - especially for the valve in the hot water line.
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bill h
el segundo
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professor95 wrote:
You also have a check valve in the cold water line that is common to the water pump outlet and city water hook up. This is installed to keep water from the city water side from flowing into the pump and possibly causing damage or backflowing into your water storage tank.
The pump itself has check valves on the outlet side that do this.
Bill and Susan
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professor95
Mechanicsville, VA
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bill h wrote:professor95 wrote:
You also have a check valve in the cold water line that is common to the water pump outlet and city water hook up. This is installed to keep water from the city water side from flowing into the pump and possibly causing damage or backflowing into your water storage tank.
The pump itself has check valves on the outlet side that do this.
One thing I am not, Bill, is a plumber. I can glue PVC or ABS plastic together with solvent but when it comes to valves, flow controls, vacuum breakers, etc. I am admitedly unknowledgeable. My field is education and electrical engineering.
Yes, I remember something about Surflow pumps having this feature built in. Flojet most likely does too. So, following what you are telling us, the check valve does exist but is not an "add on" valve - it is part of the pump.
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garym114
Texas
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My solution - Just run the water heater long enough to warm the water, turn it off and take a shower using only the hot water. No hot/cold adjustment necessary.
2000 Sea Breeze with 1998 CRV Toad in Dawson Creek - Start of Alaska Highway
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RealtyRoy
NW Oregon
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garym114 wrote:My solution - Just run the water heater long enough to warm the water, turn it off and take a shower using only the hot water. No hot/cold adjustment necessary.
That's what we do. I don't run the heater any longer than I need to get a nice warm temp. Run it in the morning for shower and dishes and turn it back off again. Run it again at night for dishes for about 10 minutes and its plenty hot for doing dishes.
It takes a little more thought to monitor how long the heater has been on but I don't mind.
Good post though, I enjoyed reading it.
Roy
May the roads and skies always be clear, and the firewood nice and dry!!
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Tvov
CT
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garym114 wrote:My solution - Just run the water heater long enough to warm the water, turn it off and take a shower using only the hot water. No hot/cold adjustment necessary.
I don't know how long to let the water heater run to just warm the water.... our heater makes the water HOT!!
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2RVers
Florida
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Professor95 - I have a question, is there enough pressure from the onboard pump which I don't think is putting out 40+ psi (like the city water connection), to open a back flow valve?
Rob and Jet
2000 Ford F550 with custom bed
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LarryJM
NoVa
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quabillion wrote:RJsfishin wrote:, I get the job done before the water has a chance to get too hot or too cold.
Swing and a miss.
The problem being addressed here is the on/off valve on the shower head allowing backflow from cold to hot to occur. Not running out of hot or cold water, or temp changes over the span of the shower.
If you never use the valve on the shower head, then you will never experience this "issue".
How can that happen in a pressurized system within a min or less. I don't see a problem or the necessity for this. The water temp mix at the valves even with a shower head extension is the same and the longer you wait the cooler the initial temp will be if you shut it off, just like in your stick home.
Larry
2001 standard box 7.3L E-350 PSD Van with 4.10 rear and 2007 Holiday Rambler Aluma-Lite 8306S Been RV'ing since 1974. TRAILER MODS
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professor95
Mechanicsville, VA
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2RVers wrote:Professor95 - I have a question, is there enough pressure from the onboard pump which I don't think is putting out 40+ psi (like the city water connection), to open a back flow valve?
Yes. I tested that too. The terminal pump pressure will be something like 35 psi. It can be adjusted up or down with a screw on the pump head.
* This post was
edited 10/13/08 07:01pm by professor95 *
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