On Demand Water Heater not getting water hot.

[rgolding]

Thought I'd share a new experience and the solution.
For the last 6 years, we have traveled extensively in our 2016 Seneca 37FS. It has the On Demand Propane Water Heater and we have learned to live and work with this without a problem.

Over the last year, I took the automatic, cheap water flow regulator out of the system because it was so slow to fill the tank. When we got to our normal Winter location in Florida, I did not install the regulator. We started experiencing a lack of hot water. Realized, that after a new pressure regulator was installed on the campgrounds well, we were getting to fast of flow past the water heater at the RV. It may get up to 52PSI. I installed our old, cheap, no adjustment, pressure regulator and the flow turned to nothing or almost nothing. Hot water, but unacceptable flow. Ordered a new adjustable regulator that is set at 40 lbs, but has an adjustable screw on it, if that is not what the gauge reads. Problem resolved! Whether its "O" rings or granulated crude, that eventually blocked the old cheap regulator, it is now replaced. May play with old regulator with some CLR, but from now on I'll use a regulator with a gauge, so I can see what is happening.

[Grumpy]

Originally Posted by rgolding

Ordered a new adjustable regulator that is set at 40 lbs, but has an adjustable screw on it, if that is not what the gauge reads. Problem resolved!

I always modified a whole house adjustable regulator since that didn't have the small orifice that you normally see on RV regulators. Well worth the investment.

[Jagiven]

Hello Rgolding, I do not have an on demand WH in my TT, but I do have on in my house. Couple questions;

How much do you use your water heater?
Is it always full of water?
Have you ever cleaned the water lines inside the WH?

The instructions on my WH state to clean the internal lines at a minimum every two years. The instructions state to circulate white vinegar full strength through the system for one hour. On our SBH, code required an isolation values for this purpose.

Might be worth trying.

[CrowCross]

Worth a shot....wife said...we have no hot water....I'm thinking, boy is this going to cost considering we were camping.

Got online and learned about a reset button in the heater unit outside....pushed it with a bic pen to keep my fingers out....and it worked, hot water....I was a hero!

I doubt this is your problem because I think low flow and a high heat demand caused it to trip......but for someone skimming this post it may be Gold some day.

[SloPoke]

Originally Posted by CrowCross

Worth a shot....wife said...we have no hot water....I'm thinking, boy is this going to cost considering we were camping.

Got online and learned about a reset button in the heater unit outside....pushed it with a bic pen to keep my fingers out....and it worked, hot water....I was a hero!

I doubt this is your problem because I think low flow and a high heat demand caused it to trip......but for someone skimming this post it may be Gold some day.

And for those who are out in the freezing temperatures of winter right now - who rely on your Girard to have the freeze protection system working - if that reset button is tripped, you don't have freeze protection!

And.. by the way - we discovered the hard way that the Girard tankless water heater is rock solid in winter temperaturs of 10-30F. I heard it kick in a couple of weeks ago at night and run for a few seconds... It startled me a bit since nobody was in the Seneca at the time and no water was running (not winterized, pump is on) It was about 30F at the time...

After I figured out why it came on... after all these years in the COLD, I was all smiles

[rgolding]

SOOOO, I thought I had this problem resolved. Maybe, maybe not. I think I'm dealing with multiple problems. Early this colder season (we are in middle Florida), I had a concern with my portable 20 lb auxiliary system. The hose for the attachment for the portable tank had developed a leak and had to be replaced. We have used this "extended stay" auxiliary portable tank for the last 6 Winters. No clue if this is part of my problem. New hose seems to be working well and fixed that problem.

Still trying to figure why our demand hot water heater has decided to not heat the water really hot. Pressure outside water is now gauged and stays constant at 40 PSI.
Noticed that when I lit on the flame on the stove, it is nice and normal. if I turn on the hot water, the stove top burner diminishes to a very low flame. Goes back to normal if water is turned off. It works the same whether on the mounted propane tank or the "extended stay" 20lb. tank.

Only common denominator is the propane regulator. We are surviving, by taking "Navy Style" showers with very low water pressure to get enough hot water.

Any opinions?

[theracqueteer]

Check to make sure your propane regulator is supplying the proper pressure. We had a problem with ours being intermittent. Sometime it worked better after using the stove. Turned out to be the regulator. Now we have a problem with it heating the water too hot even when we turn the setting down.

[memphis02]

Originally Posted by rgolding

SOOOO, I thought I had this problem resolved. Maybe, maybe not. I think I'm dealing with multiple problems. Early this colder season (we are in middle Florida), I had a concern with my portable 20 lb auxiliary system. The hose for the attachment for the portable tank had developed a leak and had to be replaced. We have used this "extended stay" auxiliary portable tank for the last 6 Winters. No clue if this is part of my problem. New hose seems to be working well and fixed that problem.

Still trying to figure why our demand hot water heater has decided to not heat the water really hot. Pressure outside water is now gauged and stays constant at 40 PSI.
Noticed that when I lit on the flame on the stove, it is nice and normal. if I turn on the hot water, the stove top burner diminishes to a very low flame. Goes back to normal if water is turned off. It works the same whether on the mounted propane tank or the "extended stay" 20lb. tank.

Only common denominator is the propane regulator. We are surviving, by taking "Navy Style" showers with very low water pressure to get enough hot water.

Any opinions?

That is an interesting diagnostic that the stove is not sustaining flame while the H/W/H is running. Definitely would be worth swapping out regulators to see if the problem is resolved. I have had 2 regulators die on me in freezing temps, however, their mode of failure was that they permitted no LP flow at all. I bought one at a KoA and paid a small fortune, but I now carry a spare with me and in doing so, have never had another die. Better to have it and not need it, I guess... LOL

I had posted an extensive thread about my girard, earlier this year. My issue stemmed from a crudded up flow sensor and screen not allowing appropriate flow into the H/W/H. I was able to remove the screen and replaced the flow sensor to fix my issue. I also added a check-valve to prevent water from backing up and bouncing the line causing the girard to come on when someone flushed the potty during that repair.

[SloPoke]

Originally Posted by rgolding

SOOOO, I thought I had this problem resolved. Maybe, maybe not. I think I'm dealing with multiple problems. Early this colder season (we are in middle Florida), I had a concern with my portable 20 lb auxiliary system. The hose for the attachment for the portable tank had developed a leak and had to be replaced. We have used this "extended stay" auxiliary portable tank for the last 6 Winters. No clue if this is part of my problem. New hose seems to be working well and fixed that problem.

Still trying to figure why our demand hot water heater has decided to not heat the water really hot. Pressure outside water is now gauged and stays constant at 40 PSI.
Noticed that when I lit on the flame on the stove, it is nice and normal. if I turn on the hot water, the stove top burner diminishes to a very low flame. Goes back to normal if water is turned off. It works the same whether on the mounted propane tank or the "extended stay" 20lb. tank.

Only common denominator is the propane regulator. We are surviving, by taking "Navy Style" showers with very low water pressure to get enough hot water.

Any opinions?

BINGO... I went and tried the same...

one burner with water heater = all good
Two burners w/ Girard running = all good
three burners w/ Girard running = slight pulsating of the flame on the stove.

Have you checked to see if the little vent hole on the regulator is plugged up? critters built a nest in that hole? or if not - replace the regulator.

[rgolding]

Thanks everyone for thoughts and replies. I cleaned and made sure regulator was clear. Found no obstruction or dirt near the screen vent. Plan to have a service tech look at this whole situation on Thursday and will post the results. I just need to have someone else take an independent look at this whole situation.

Temps returned to low 60's overnight yesterday and we have plenty of hot water again. This whole problem really just seems shows itself when temps are in low 40's to high 30's.

Steve, thank you for experimenting with your burner on the stove. That really supports my theory that the regulator is not supplying a steady flow of propane.

Stay tuned, this is an interesting problem. I promise to report results.

[rgolding]

So the RVForce Technician arrived on time. I showed him my experiment with the stove burner and he checked out the regulator. He brought a meter that measured the 11psi at the burner by removing the burner and attaching a hose. He then turned on the demand hot water and watched the pressure drop to 6psi and stated that wasn't right. Pulled off a black rubber plug, that I hardly new was there, and adjusted a flat black screw surface with his thumb. Turned it about 3 times around. Went inside and verified that it did increase water heat without dropping the pressure at the burner. Added a second burner with a flame, instead of a gauge and watched the gauge drop. He felt he gave us a temporary fix, but said he felt we should replace the regulator. He stated I could order the regulator and replace it myself or they would take care of it. I was very impressed with this. Since I've fiddled with this through a new "extended stay" hose, a new water pressure regulator and then the LP regulator problem, I asked that they replace it and get us back to fully operational hot water. I do live with SWMBO and she likes hot showers and feels I've experimented enough. The new LP Regulator is ordered and they will install and check its working capability, when it arrives. Stay tuned.

[SloPoke]

glad you got it figured out!