J-D, I am running from a campsite and using a regulator. It is possible that the water pressure is fluctuating from the source.
Golden HVAC, you also may be on to something. I checked my water flow and determined that I am getting a little less than 3/4 gallons per minute. Since there is no way to increase the water flow on this campground, I will have to wait until I get home and test it there.
Thanks for all of the replies. They were all helpful. I will let you know what I eventually find out. Thanks again.
Don't know why it didn't take, but last night I tried to post a snippet from Atwood saying basically Regulate Like at Home. Today I found This Presentation on the Atwood site.
It's 11 pages but I quickly found two useful points and and at least one not so useful:
Useful: Add Cold to Control Temperature, and Variable Flame Valve
Not so Useful: No Customer Training Required.
I really don't see why I'd ever want one of those things. I tried to be neutral on the OP, but no point in staying on the fence.
God Bless, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100
Buddyg23 wrote: I had a tankless hot water heater installed in my 2011 Jayco Greyhawk a couple of weeks ago. I was told not to use the cold water to regulate the temperature. Instead you use the flow of the hot water . For cooler temp. you turn the hot water valve all the way open. For warmer you close it off a little. My problem is that this does not work. The temp fluctuates between scalding and freezing. One minute it will be so hot you can't stand it and the next it will be cold. I have taken it back to the installer. He does have any idea whats wrong. Does anyone know a fix for this?
I had thought about doing this with mine when we ordered it. I talked to my dealer and Winnebago. Winnebago would not install it during the build and my dealer said before I spent the money to just give the 6 gallon water heater a try. I also posted here about it and the general response was to heat the 6 gallon with both gas and electric. This actually works quite well and you can get two decent showers before running out of hot water. Winnebago, my dealer, and this forum saved me the cost of the tankless. If you can get your dealer to swap it out this may be a viable option for you. Hope it works out for you.
Todd
Todd, Shirley, and the "Maddawgs" min-pins Precious and Buster Brown
2011 Itasca Cambria 30C
2011 Demco KarKaddy 460SS
TST 507 RV TPMS
"if there is anything left when we are gone, then we miscalculated"
Words from Camping World's page that I intended to send last night:
Energy-efficient, propane-fired heat exchanger heats water only as it’s needed. Uses no energy to keep water hot in a tank plus it saves up to 100 lbs. of water weight. The flow regulated modulation valve automatically adjusts the burner input based on water flow rate for optimal operating efficiency. High output burner delivers hotter water on cooler days.
Works just like at home—simply turn on the hot water and mix in cold to reach desired water temperature. Easily adapts to replace virtually any brand of standard 6 or 10 gallon water heater. Includes top adapter plate for 10 gallon and larger tank replacement. Exterior door sold separately. 12-volt.
Well I've tried everything except metering the gas flow as Golden_HVAC suggested. I think I will try that next. It looks like it is reaching the upper temp limit and then cutting off until it cools down. This would be because of poor water flow. I am at a campground right now so I can't test the flow, but when I get home I will know for sure. Thanks again for all of the great responses.
Some units have multiple burner settings which allow the number of burners in operation to be selected in order to better match water temperature, and flow. Have a look to see if yours has this accomodation.
If you are on hook-up, try opening another faucet and letting some of the hot water run. This may provide enough flow to keep the burner operating and so deliver even temperature flow. As posted earlier, this is what we needed to do with the unit at our cottage. It is not practical for non-hook-up RV use as the water requirement/waste is too great.
Buddyg23 wrote: I had a tankless hot water heater installed in my 2011 Jayco Greyhawk a couple of weeks ago. I was told not to use the cold water to regulate the temperature. Instead you use the flow of the hot water . For cooler temp. you turn the hot water valve all the way open. For warmer you close it off a little. My problem is that this does not work. The temp fluctuates between scalding and freezing. One minute it will be so hot you can't stand it and the next it will be cold. I have taken it back to the installer. He does have any idea whats wrong. Does anyone know a fix for this?
You have found out why I threw the tankless piece of *&$%***### garbage out of my house and put a power vent tank type back in.
This is roundabout, but can you use your campground supply to fill your coach's fresh water tank then run your pump to supply the hot water and shower?
Buddyg23 wrote: J-D, I am running from a campsite and using a regulator. It is possible that the water pressure is fluctuating from the source.
Golden HVAC, you also may be on to something. I checked my water flow and determined that I am getting a little less than 3/4 gallons per minute. Since there is no way to increase the water flow on this campground, I will have to wait until I get home and test it there.
Thanks for all of the replies. They were all helpful. I will let you know what I eventually find out. Thanks again.
If the campground pressure is less than 50 PSI, then you don't need the additional pressure regulator at the hose, you will not damage anything and probably will increase your flow rate.
If you are at a campground, you can try filling a 1/2 gallon container and timing it, this will give you the gallons per minute flow.
You can fill your fresh water tank, run it's pump, along with the campground water should increase your water flow to above 2 GPM!
If you must flow a bunch more water to keep the water heater from over heating, and a new shower head is not in your plans (You can not use 3 GPM very long while dry camping) you might try installing a line from the hot water to the fresh water tank filler, then by pass some water back to the tank, so hot water flow is maintained at 1.2 GPM (or whatever it needs to be) and you will still be able to take a shower at 0.8 GPM if that is your desire.
It seems like your water temperature is regulated by increasing flow through the water heater to cool off the output water, and decrease flow to warm up the output water temp.
Adding cool water and decreasing water flow through the heater will increase it's output temp to the point it will cycle off on the high temperature cut-out frequently, causing scalding hot water to become 55F water almost instantly!
You might have someone try running a little hot water at the kitchen sink while you are in the shower, and have them increase it to provide a cooler water stream, or decrease it if your shower becomes to cold.
Yes shutting the gas inlet valve about 1/3 of a turn will also slow the gas, decrease the flame height, and lower the water output for a given amount of water flow.
Buddyg23 wrote: I had a tankless hot water heater installed in my 2011 Jayco Greyhawk a couple of weeks ago. I was told not to use the cold water to regulate the temperature. Instead you use the flow of the hot water . For cooler temp. you turn the hot water valve all the way open. For warmer you close it off a little. My problem is that this does not work. The temp fluctuates between scalding and freezing. One minute it will be so hot you can't stand it and the next it will be cold. I have taken it back to the installer. He does have any idea whats wrong. Does anyone know a fix for this?
You have found out why I threw the tankless piece of *&$%***### garbage out of my house and put a power vent tank type back in.
Expensive lesson learned!!!!
C.B.
C.B.,
Probably a little to late, but I have worked on a couple of tankless water heaters at a restaurant, and they used a water tank to hold the hot water, the heaters to make the water hot. I would have suggested a 10 gallon electric water heater and a small 2-3 GPM pump. When the tank thermostat called for heat, it would have turned on the pump, and recirculated the hot water into the tank, heating it for the use throughout the house.
The electric element would not be connected to 240 volt power, just the insulated tank would be used to hold the warm water until it is needed. The tankless water heater would take in cold water from the cold inlet water line, and send it into the tank through a Tee mounted into the bottom of the tank, after the tank drain is removed, tee installed and drain put back.
My cousins also complained about the water shifting from hot to cold, and would have put in a similar tank at their place, if I had the time while visiting them. And a mixing valve that would have taken any amount of water above 110F and mix it with incoming cold water to have a regulated output adjustable from 105F to 135F. These are common on boilers and solar hot water heaters, and a requirement in MASS, where many kids where scalded each year before it became a requirement about 20 years ago.
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