On demand hot water

[Just starting]

I've noticed that in my SR300 that the on demand hot water works very well when I'm hooked up but if I'm using the units source you must throttle the flow back to keep the water hot. Is this just how it is? I have the heat turned to high. Do I need to try something different? Is there an upgrade? Thank you.

[SeaDog]

first is your on demand propane or elect? the temp of an on demand heater as I understand it is controlled by flow of water so it may be that you are getting a higher pressure (more flow) on your system with the pump then with city water (are you running a reducer). My other thought might be that if elect your generator may not be able to push the required amps as with shore power jus a WAG on my part.

[Just starting]

Thank you. The heater is propane. The flow is better with city water. It a ponderance.

[SeaDog]

That is why I put WAG (wild ass guess) in my reply. please let the forum know what you find out or how you fix the problem

[Just starting]

Lol. Yep I knew what WAG was. I've been guessing too. If I find a cure I will for sure share it. This forum is fantastic. Thank you.

[NMWildcat]

Are you using an oxygenics shower head? It creates a shower flow with more force which makes for a much better shower experience when you have to decrease flow for warmer water.

We have had park connections where the pressure was so low we filled our tank and used the pump.

We also notice if the input water is really cold (like just above freezing, we really have to turn down the flow to get HOT water, and where the input water temp is high (like in AZ where we just hit 100 near Phoenix) we have to add cold water to get the shower cold enough, even with the heater turned to low

So we have found that the input water temp makes more difference for the on demand than the actual input psi.

But all in all, we wouldn't trade our on demand water heater for anything!!!!

[Just starting]

Excellent. I also wouldn't trade the on demand for the tank ether. I certainly can live with this small issue. I was more or less trying to see if others had noticed this as well. I'm just starting to learn the quirks of this rig. Having fun. Thank you again.

[padcarroll]

I also have this issue with mine. The water heater is two stage. One set of burners for low flow and a second set for higher flow. The water pump alone never seems to deliver the flow required for stage 2. The Oxygenics shower head does improve the performance for us also.

[NMWildcat]

Originally Posted by padcarroll

I also have this issue with mine. The water heater is two stage. One set of burners for low flow and a second set for higher flow. The water pump alone never seems to deliver the flow required for stage 2. The Oxygenics shower head does improve the performance for us also.

What water pump do you have? You might look at upgrading the pump to a higher gpm pump. We did, when we had to replace our pump after a surprise freeze and it definitely improved flow throughout the rig. Might be worth looking at.

[padcarroll]

We have the high end sureflo and I rebuilt the pump last year due to one broken chamber. It is 4 gpm which is higher than the shower requires.

[amblt]

The problem is in the nature of the beast. A demand heater can only impart a specific amount of energy (BTU's) to a given measure of water (lbs) during the time said water is in the heat exchanger. If the flow is higher than the design spec, the temperature rise in the water during the time from entry to exit will not be optimum. As one person pointed out, the entry temp is also a big factor. I think the industry bases its specs on an assumed entry temp of 55F. A unit with a greater rise capability than presently available in the market may not be suitable for RV use, due to cost and/or size restrictions.

I would prefer a demand heater in both my RV and at home, but that is not an option in the froseeable future.

Cheers

[Just starting]

Thank you

[tstillman]

Originally Posted by NMWildcat

Are you using an oxygenics shower head? It creates a shower flow with more force which makes for a much better shower experience when you have to decrease flow for warmer water.

But all in all, we wouldn't trade our on demand water heater for anything!!!!

We have the Sterling edition like you and agreed on the oxygenics shower head. Great upgrade.

We had all kinds of trouble getting hot water to the kitchen and we did the scald / freeze dance in the shower. Factory replaced it with the next generation and we were able to better control temps.

We were told the first model had a 30 degree max increase of water temp as a safety measure against scalding burns. Problem came with the incoming water temp was NW cold of 50-60 degrees. Max temp was then limited to a tepid 80 - 90 degrees. Add to that the distance of the hot water run to the kitchen meant zero hot water for dishes.

Good system just went through some growing pains.

[Just starting]

Factory upgrade? Warranty? With the new heater the shower is less temperamental? Did you go back to the dealer or deal direct with the factory? Thank you.

[Just starting]

It's a Garard heater.

[RadRik]

Originally Posted by tstillman

We have the Sterling edition like you and agreed on the oxygenics shower head. Great upgrade.

We had all kinds of trouble getting hot water to the kitchen and we did the scald / freeze dance in the shower. Factory replaced it with the next generation and we were able to better control temps.

We were told the first model had a 30 degree max increase of water temp as a safety measure against scalding burns. Problem came with the incoming water temp was NW cold of 50-60 degrees. Max temp was then limited to a tepid 80 - 90 degrees. Add to that the distance of the hot water run to the kitchen meant zero hot water for dishes.

Good system just went through some growing pains.

I have the same year Sterling with the same problem you described tstillman. I got nowhere with Wildcat or Garard. So you are saying that upgrade helped get hot water to the kitchen? Was that done at your cost or did Garard cover it?

[NMWildcat]

Our 2012 Sterling 32RL still has the original Girard gen 1 on demand. I guess we are just lucky as we have never had any of the problems described by others.

We were in Williams AZ a month ago where input water temp was 40 degrees. We had to barely turn on the hot water to lower the flow rate enough to get hot water, but it was hot, just not as strong a shower as usual. So don't really believe the 30 degree differential max. Never had the cold/hot cycle. Kitchen hot water is just fine. Very small time to wait for hot water anywhere.

Would love to know what the difference is in systems. Makes me wonder if we buy a new rig, if a different on demand will suffer from all the ailments we hear about.

[Gmar60]

I don't have tankless water heater in my Surveyor but I do at home. Initially all was well after install but then my plumber buddy visited and adjusted a few things[emoji15] he removed the flow restriction in shower head and raised the temperature setting on heater. Now everything was GREAT! I decided that hot blasting shower was wasting a lot of water so I put restriction back in shower head. After a few seconds in shower, bam. Ice cold[emoji848]. Had to lower heat setting because it requires a minimum flow at a certain temp. Your on-demand system may be experiencing a similar situation with difference in flow rate between city/tank pressure.

[RadRik]

Originally Posted by NMWildcat

Our 2012 Sterling 32RL still has the original Girard gen 1 on demand. I guess we are just lucky as we have never had any of the problems described by others.

We were in Williams AZ a month ago where input water temp was 40 degrees. We had to barely turn on the hot water to lower the flow rate enough to get hot water, but it was hot, just not as strong a shower as usual. So don't really believe the 30 degree differential max. Never had the cold/hot cycle. Kitchen hot water is just fine. Very small time to wait for hot water anywhere.

Would love to know what the difference is in systems. Makes me wonder if we buy a new rig, if a different on demand will suffer from all the ailments we hear about.

I may try to use the low flow setting again and see if I get more hot water. The shower is fine, but both sinks take forever to get lukewarm water whether on city water or tank and pump. I checked the flame and it stays on the whole time I am running water which is why I don't understand why it isn't heating the water.

[Gmar60]

Any water heater still has to push all the cold water out of the lines before your heated water reaches faucets.