A different tankless water heater issue

glitelover · 05-03-2017, 11:13 AM

I mentioned this in another thread, but it was buried with other stuff, so I'm separating it out in hopes of getting some feedback.

We took the new 375 BHFS out for its first trip last weekend, and the water heater gave me fits. I've seen lots of discussions here on the board about them, talking about how the water is not hot enough or is just lukewarm.

Well, ours took a while to get hot--I had to run the water in the shower probably 30 seconds before it got hot (which we expected). After that, I jumped in the shower, and there would be random cold spots (I mean freezing cold), and then after maybe 10-15 seconds, it would get really hot again. Nobody else was drawing any water at the same time. I had the faucet turned all the way to the left (hot) the whole time.

We were using water from the fresh water tank (no water hook-ups), so we were trying to conserve water, but running the water every time to get hot water made it difficult. That part I could deal with, if it weren't for the random hot/cold/hot/cold.

Is this normal for these systems, and/or is there something I could do to fix it?

pconroy · 05-03-2017, 11:51 AM

I'm not sure if you have the Girard tankless heater, but odds are you do. Then which model of Girard you have (there are three Gen I, II and III). With a 2017 you probably have a Gen III.

The Gen III Girard went thru a recall on the solenoids. Maybe that's what's going on.

We have a Gen II in our motorhome and learning to live with the Girard takes some experimentation and some compromise on our part. But, in general, no. We don't have sudden bursts of cold water when on the water pump.

Maybe someone with your exact unit will have some better advice, but I'd probably start by making sure your unit isn't impacted by the recall.

Then, see if you can get a steady stream of hot water using the tank and the pump and lowering the flow rate. Pick some different thermostat settings.

Another idea would be to stand outside next to the heater (I'd probably pull the cover off) and watch/listen to the flame while the hot water is running. If the heater flame is cutting out, then something's amiss.

DanNJanice · 05-03-2017, 12:16 PM

I have no experience with your particular water heater. However, i have a small portable tankless water heater that I use for around the house. It requires a minimum water flow in order to turn on the "burner". I assume the tankless water heaters in trailers work the same way.
Anyway, play with the water flow, try turning it up to full, connect to city water so you have good pressure, etc. See if any of those changes make a difference.

**norty1** · 05-03-2017, 01:23 PM

Most reports I read indicate that those who are getting their water supply from the onboard pump will never be happy with the tankless.

As the flow pressure reduces between pump cycles, the wh shuts off. cold water blast, wake up call!

glitelover · 05-03-2017, 05:09 PM

Thanks to everyone for the responses. It sounds like we need to hook up to "city water" in the driveway and see if the same thing happens as our next step.

pconroy · 05-03-2017, 05:26 PM

Quote:

Originally Posted by glitelover

Thanks to everyone for the responses. It sounds like we need to hook up to "city water" in the driveway and see if the same thing happens as our next step.

A great test but...

Actually my experience was the opposite. If the water flows too fast, it won't get hot at all. It's lukewarm. And city water usually comes in with a lot of pressure.

We get the best, consistent flow using our on-board pump and the tank. But give it a shot and see what happens.

Donna · 05-03-2017, 06:01 PM

Glitelover, unfortunately I do have some experience with the Girard System LOL! I have a 2017 North Point and I have the Girard Tankless GEN II, I thought is was the latest and greatest, I might be wrong. Anyhow, I was having similar problems and what I did is, on the back of unit I adjusted the flow control, if you have too much flow it can cause the burner not to come on as often as it should or you would like. Mine was hard to reach..... needed an arm stretcher lol. I believe I turned mine counter clockwise to slow the flow. Also the temperature of the water can effect the way the system works also. I find the lower the flow out of the shower head the more reliable the system is.

crumgater · 05-17-2017, 10:48 AM

From other posts here on the forum, my understanding for best performance in the shower, is that you want to adjust the temperature coming out of the heater to be exactly the temperature you want your shower - so you're using 100% flow through the heater for your shower. That way it won't cycle when you're rinsing.

I'll be testing this theory this weekend...

Ste14mi · 05-21-2017, 06:37 PM

Had this problem on our 2017 FBTS, after the recall for the solenoids was performed.

Turns out that these tankless heaters do not function properly if you put a pressure regulator on your water line into the RV. Got this straight from the manufacturer.

Amazed that there was no note (that I saw anyway) or sticker warning not to use a regulator. Removed mine and the problem went away.

blujay40 · 05-21-2017, 07:08 PM

Using pressure regulators with my Girard Gen 3 Tankless water heater has NOT been an issue whatsoever.

I have used both a Watts 263A adjustable pressure regulator as well as a Fairview full flow fixed pressure regulator in combination with a double canister water filter and still have no issues with my Girard shutting down.

Just make sure the regulator your using is a true "pressure" regulator that does not limit flow as the main way to control actual water pressure at the tap. I have also removed all water restrictors in the faucets and shower head to ensure I can maintain a good flow rate at that end.

Of course, if your at a campground that has low water pressure to begin with, then the battle is already lost and in those instances, I just fill my fresh water tank and use the pump.

crumgater · 05-22-2017, 11:21 AM

My test was successful this weekend.

There was a 50psi regulator on the spigot at the CG (not mine).
Our regulator is a fixed 35psi (not installed during the test)... the Seneca manual says to use a 45psi regulator. So, looks like we'll be shopping for a new one to keep in the RV.

I dialed the temp down quite a bit on the heater, and it was still too hot for me once I got in the shower, so I dribbled in about 5% more cold... with no noticeable cycling of the heater.

Worked great with my Oxygenetics shower head.

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