Tankless water heater issues

[Rick-in-Houston]

My Girard tankless water heater (model GSWH-2) works great. What I found out after having inconsistent water temps is not use a standard pressure regulator at the site. I purchased an adjustable water regulator and set to 55-60 psi and the Girard works great.

https://www.youtube.com/watch?v=iN_uaj54NF4

[pconroy]

Thank you Rick!!

I suspected as much, that my cheap Camco regulator was contributing to the problem.

[Michigan-Traveler]

I am looking at a 2018 29MV Prestige, and have been searching this forum for information that is helpful in making a good decision. As I read these comments about the "on demand" water heaters I found it interesting that for 2018 they have went back to old style water heaters which is my preference.

[DonaandDon]

We found the cutout button on the hand wand in the shower was not in the fully on position and would not allow the tank-less to fire. Good water pressure is key.

[LI-Camper]

I have a newer model Girard water heater with the digital temperature control. It replaced the original Girard and it works well. Once it wasn’t working because the fresh water hose was kinked. Check your hose to make sure it is delivering the proper pressure to your M.H.

[Forelyndogs]

We use an Oxygenics Spa shower head. It claims to be low flow and it does use less water than the non-low flow that came with the rig. It works fine for us. I do agree that there is a water waste issue with these on-demand water heaters. We are happy with ours primarily because we stay about 95% of our time in campgrounds with full hookups. When on those rare dry camping excursions we are extra careful with our water use. The real value of the on-demand to us is the dramatic reduction in propane use. Likewise, as they advertise the units, it does provide more or less unlimited hot water, something a six gallon won't do. Though most RV'ers would never use that much hot water!! Without a doubt, the original units, as ours is, were poorly designed and difficult to manage. The newer units, the ones they are now installing, have resolved most of those issues. If we needed to replace our water heater, we would do so with the new model on-demand unit. Unfortunately, I suspect we will be years before that happens.

[hosehose]

Originally Posted by Ceck

I just recently purchased a 2016 Greyhawk 29MV that is equipped with a tankless water heater. This is my 4th RV, second motorhome. We have had nothing but problems with this water heater. Inconsistent water temp. Having to reset the unit with almost every use. I was wondering if others are experiencing similar issues and has Jayco addressed them?

I know this is several years later but here's the takeaway to successful use of a tankless system:

1) set the temp switch at the water temp you want, say, for example, 101F

2) Open ONLY THE HOT VALVE and wait for the water heater to kick on and for the temp to stabilize at, in this example, at 101F. You're done...don't ever touch the cold water valve. If the water is too hot dial it down at the wall switch but DO NOT OPEN THE COLD VALVE EVER!!!!!

The reason why is that many people make the mistake of treating this tankless system the same as they treat a tank system and they set the tankless temp to say, 130F and then dilute the hot water with cold water when showering thinking this somehow "extends" the ability of the system to provide hot water. It doesn't. It does extend the capability of a tank system but not for a tankless system. The tankless system can provide unlimited water at any temp you want with no cold water dilution being required. In fact, opening the cold water valve on a tankless system only upsets the pressure in the hot water line and this is what leads to surges (and complaints) about fluctuating scalding and then cold water.

So...set the temp you want with no cold water dilution and open only the hot water valve and these tankless systems work great.


Also, be advised that if you stop the flow to lather up and then restart it to rinse off, that you will get a slug of cold water in a tankless system. This is because when the system senses that you stopped the water flow it also stops pouring heat energy into the water. Then when you restart the shower the system takes several seconds before it senses that the flow has returned before it fires up the propane heat to heat the water. During this time, the water is flowing but is not being heated and when it reaches the shower head it's all cold water. Several seconds later the hot water resumes.


So if you stop the flow to lather up, move to one side when you resume the flow and wait until hot water begins to flow again.

[hosehose]

Originally Posted by pconroy

Thank you Rick!!

I suspected as much, that my cheap Camco regulator was contributing to the problem.

It's not that so much as in the way you use it. Set the temp you want and only open the hot water valve....no cold water mixing. Using cold water upsets the flow differential and causes scald/cold spurts. If you only open the hot water valve then it works great.

Also, be advised that if you stop the flow to lather up and then restart it to rinse off, that you will get a slug of cold water in a tankless system. This is because when the system senses that you stopped the water flow it also stops pouring heat energy into the water. Then when you restart the shower the system takes several seconds before it senses that the flow has returned before it fires up the propane heat to heat the water. During this time, the water is flowing but is not being heated and when it reaches the shower head it's all cold water. Several seconds later the hot water resumes.

So if you stop the flow to lather up, move to one side when you resume the flow and wait until hot water begins to flow again.

[anf76]

they are a pain the the neck. my last one had a tankless water heater. hi- temp sensor went bad, fixed under warranty. i wouldn't want one in a rv. i have one at home, takes a little to get use to. uses a lot more water

[pconroy]

We've come to understand their quirks and can now get a nice hot shower. Several, in a row as a matter of fact.

[Dave_Jan]

Bought this one today to overcome wasting fresh water waiting on the hot. Not smart enough to add plumbing to recycle fresh water while waiting for hot water.. Will post results

[hosehose]

Originally Posted by anf76

they are a pain the the neck. my last one had a tankless water heater. hi- temp sensor went bad, fixed under warranty. i wouldn't want one in a rv. i have one at home, takes a little to get use to. uses a lot more water

But they use less energy. It's when you're NOT using water that tank less systems save energy and 99.6% of the time you're not using water. A normal tank system uses energy to keep the water in the tank up to set temperature but a tank less only uses significant energy when you're using water.....

[pconroy]

Originally Posted by hosehose

But they use less energy. It's when you're NOT using water that tank less systems save energy and 99.6% of the time you're not using water. A normal tank system uses energy to keep the water in the tank up to set temperature but a tank less only uses significant energy when you're using water.....

I'm also not convinced that my tankless uses a LOT more water. More? Perhaps. A lot more? I don't know.


Most of the cold water in our RV comes from the distance between the tankless and the shower. Replacing it w/ a tanked won't help that.

[Robbbyr]

Originally Posted by pconroy

I'm also not convinced that my tankless uses a LOT more water. More? Perhaps. A lot more? I don't know.


Most of the cold water in our RV comes from the distance between the tankless and the shower. Replacing it w/ a tanked won't help that.

I replaced my Girard with a 10-gallon Atwood XT, plus I installed a recirculation loop. Recirculated water flows back to fresh tank so I don't waste a drop waiting for it to get hot. Press the recirc switch, timer opens solenoid valve for 30 seconds, hot water then available at every fixture. Having a tank-style heater also allows me to "trickle" the shower, something difficult for tankless to keep consistent water temps. No hot/cold spikes. Plus any site where I have electricity the campgound is heating my water instead of always burning my propane.

[hosehose]

Originally Posted by pconroy

I'm also not convinced that my tankless uses a LOT more water. More? Perhaps. A lot more? I don't know.


Most of the cold water in our RV comes from the distance between the tankless and the shower. Replacing it w/ a tanked won't help that.

The cold water also comes from the 2-4 sec delay before the tankless even turns on.


When you turn on hot water and have a tank, hot water begins to flow towards the faucet and once it reaches the faucet you have hot water.

When you have a tank less system and turn on the hot water here's what happens:


1) there's an approx 2-4 sec delay until the system recognizes there's sufficient flow before it turns on the heater and during this time, you get cold water at the faucet


2) Then once the min flow has been detected, it ignites the propane heater in the tank less system and then and only then is hot water BEGINNING TO FLOW but you still have to wait for the hot water to reach the faucet from the heater.

So...both systems make you wait for hot water to reach the faucet but the tankless system has an additional 2-4 sec delay before you get hot water and if you are dry camping, this is wasted water.

The nice aspect of the tankless is that when you do have a full hookup (water, elec and sewer) you have endless water and a place to dump it. This means that with a tankless system you could take a 60 min shower and never run out of hot water whereas with a tank system you would probably run out because the burner in a tank system is much smaller than the burner in a tankless system.....



Also, when I was talking about energy savings I was assuming you keep the tank system on all the time. When I had a tank system I only turned it on 10 min before I used it and then turned it off after I was done to save propane.

[LI-Camper]

Originally Posted by NC Roamer

I think the newer Girard tankless water heater (model GSWH-2) better monitors the temperature of the water stream. If anyone has one of these, I'd be interested in how well it works.

We have the GSWH-1M and have had some of the same issues as others, but with some practice we are making it work.

I replaced the original Girard with the next generation Girard . Jayco sent me the replacement for free. The second one is much better. You can dial in the water temperature with the digital monitor. It is not perfect, but it works well. I don’t use as much propane as I used to with a tank based water heater. I use the Oxygenics shower head with no problem.