Rinnai R75LSi - Hot water problems for over a year!

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skasdan

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I will detail this as much as I can and am so hoping someone can pinpoint our problem. We moved into our renovated home last November. We have not had consistent "working" water since we moved in. We have a deep private well - at least 300 ft - and a new tankless hot water heater. Not all of the piping is brand new but I am pretty sure all of the piping around the hot water heater and water pressure tank is new. We have had several plumbers come out over the past year and did have a new well pump (submersible) installed. So here is what is happening...
I will use the shower as the prime example. When I first start the shower, the water comes out with great pressure. It doesn't get hot immediately and sometimes even takes a few minutes to heat up, which I find odd with the on demand hot water heater. After a few minutes, the water starts to lose pressure. Then more, more, more until it just trickles and stops. The shower has a one handle cold on on end, hot on the other. Even when I turn the faucet all the way to the cold side, no cold water comes out! Usually if I wait a few minutes and turn the shower back on, the water pressure comes on strongly again but the same thing happens. Sometimes the water slows down to a trickle but remains hot/warm and sometimes the water turns frigid. This happens in our entire house, in all bathrooms, at all sinks - some have single handle faucet, some have double faucets. It also happens with our washing machine. When we run hot/cold or warm/cold cycles, it almost always stops with the "not filling" signal. When we wash on cold only, it seems to run fine. I believe there was one day after our new pump was installed that the water seemed to last all day - but that was just for a few laundry cycles and washing dishes. Also, after our pump was installed there was A LOT of sediment in our water. Not rusty or calcium-like, just sandy/silty/dirty. It lasted for about two weeks (it has been about a month since our pump was installed). We flushed out the tank, etc. but everything did got pretty clogged. We did - and continue - to flush our aerators in every room (taking off shower heads, etc). For a while it seemed like there was a lot of air in the lines - lots of sputtering, etc but now it just seems to fade away or not work at all. The cold water pretty much always seems fine unless we use the hot water, lose it, then try to switch to cold. I am hoping there is some reasonably easy explanation because we simply can't afford to keep paying plumbers and well service people to come check, charge us for the time, and not have it resolved. We have been diligent about cleaning out our sediment filter on the tankless hot water heater. Every time we do it, we get excited and think it's going to be fine but the same thing happens over and over. Does this sound common? We are still experiencing a lot of sediment in our toilet tanks. Should it be cleared up by now?? We are so hoping to not go through another whole winter with this problem. We haven't been able to take regular showers since we moved in! Any advice would be so very appreciated!
 

Reach4

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You may have more than one problem.

Let's start at the beginning. Does your water pressure gauge stay within its normal range (30 to 50 PSI maybe) during your problems?

Regarding sediment, I think I would turn on a hose on full outside the house and let the pump run for a couple hours. Watch the pressure gauge. If your pressure stays up, your well is not running dry. If it shows signs of running out of water, turn off the pump, and let thing recover.

Besides testing, running the water outside (presuming not hard frozen yet) may help get rid of some sediment. Sediment may decline with time and water use. Even so, I would put some kind of sediment filter into place. I am not sure what I would use, but I tend to like the 20x4.5 Pentek Big Blue filter housings and filters. One may do it. If not, there are more potent filters.

Do you have a water test? There are backwashing filters that can take out sediment plus do some other treatment. The Big Blue are lesser filters. May or may not be sufficient. Those are reasonably priced, and there are a lot of non-proprietary filter elements.

If the water pressure is OK, where is the problem? Maybe the water heater. But I would start with checking out what is before the water heater.

I am not a pro. Just trying to think thru your symptoms.
 
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Terry

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I like the idea of getting a whole house filter for that.

I have a tankless water heater at the moment, and depending on distance, it can take a while to get hot water to a shower. I have also used them where the tankless was within several feet, and it took a very short time. The unit needs to heat up from a cold start. I'm considering running a large gas pipe to a new location under the two baths I have upstairs and relocating the tankless. Either that, or adding a recirc to it and leaving it where it is.
Without a recirc, the tankless is always going to take more time to get hot water. I feel guilty letting that much cold water go by.
 

skasdan

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You may have more than one problem.

Let's start at the beginning. Does your water pressure gauge stay within its normal range (30 to 50 PSI maybe) during your problems?

Regarding sediment, I think I would turn on a hose on full outside the house and let the pump run for a couple hours. Watch the pressure gauge. If your pressure stays up, your well is not running dry. If it shows signs of running out of water, turn off the pump, and let thing recover.

Besides testing, running the water outside (presuming not hard frozen yet) may help get rid of some sediment. Sediment may decline with time and water use. Even so, I would put some kind of sediment filter into place. I am not sure what I would use, but I tend to like the 20x4.5 Pentek Big Blue filter housings and filters. One may do it. If not, there are more potent filters.

Do you have a water test? There are backwashing filters that can take out sediment plus do some other treatment. The Big Blue are lesser filters. May or may not be sufficient. Those are reasonably priced, and there are a lot of non-proprietary filter elements.

If the water pressure is OK, where is the problem? Maybe the water heater. But I would start with checking out what is before the water heater.

I am not a pro. Just trying to think thru your symptoms.

Hi, I appreciate your response. We did do exactly that about a week after the pump was installed. The water ran for close to three hours before we had to let the well recover. The sediment issue has seemed to let up, for the most part. We still notice a little in the bottom of our toilet tanks but drinking water is totally clear. The issue is the loss of the hot water pressure every time we run it for more than say four or five minutes consecutively. I've read somewhat similar posts and many of them say it could be a clogged pipe from mineral build up. It's frustrating because since the piping right near both the pressure tank AND the hot water heater is all new, insulated, and we don't even have hard water - no build up in sinks or tubs. Does anyone know anything about the temperature settings on tankless heaters? I recall reading that sometimes if the water temp is set too high, something like this may occur. Ours is set at 120 so not sure if that qualifies as particularly high. This is definitely a hot water issue only - cold is always fine now, with the new pump. As far as I know the pressure is holding up during use. The cold water never seems to have any trouble and I have done experiments checking the pressure gauge at random times during the day - no showers going on or anything but it holds between normal (I think ours is 20/40 but can't recall now that I'm trying to!). Also, we were able to run the water to flush out the water pressure tank for a couple of hours steady so I am wondering what on earth could be causing the hot water to lose pressure so quickly!
 

Hudson Reed Dan

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We dealt with a customer recently who had a similar problem to yours, the cause was a hot water heater where one of the heating elements was broken, so any demand for hot water beyond a small amount caused the system to fail.

It would be helpful if you could put paragraphs in your writing, it is quite hard to read without them due to the way the forum bunches the text up.

Hope you get it sorted.
 

DonL

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I feel guilty letting that much cold water go by.


I would also.

I can not see a tankless lasting very long unless you have very Good filtered well water.


What is the model of this water heater ? How old is it ?


Good Luck on your project.
 

Reach4

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At least some on-demand water heaters slow the flow if they cannot keep up with the heating job rather than letting the output water go out lukewarm. If somebody were to know about your heater and recognize that, that person would have to know what water heater you have.

Regarding checking water pressure, I think you would want to check during a problem. But if there is no problem with the cold, the water pressure at the pressure tank must be OK. Incidentally, using 20-40 PSI water is unusual. 30-50 PSI and 40-60 PSI are more common.

I am glad to hear that you are saying the problem with the cold water is gone. It is not clear if the problem extends to the kitchen sink hot, or if it is just the bathroom hot. There are mixing valves and temperature regulating faucets. If one of those with a problem is in the path of your water, that might cause some complex behavior. So I think identifying the first thing in the water path that displays a problem would be useful. So while you have the bathroom problem, how does the hot in the kitchen behave?

Regarding sediment, why not add the filter even if the amount of sediment over time is going down? I would start maybe with something like the PENTEK-DGD-5005-20 filter element. Use polypropolyne filters, such as that, and not cellulose elements, on well water. If you do get such a filter, keep an extra O-ring on hand and use silicone grease on the O-ring when you re-use or replace the O-ring during a cartridge change. If the filter does not have that much sediment to deal with, that element would last for a year. Never put such a filter before the pressure switch.
 

DonL

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I would think if is a newer heater, it will be giving you a error code.

Reading the Manual helps sometimes.


Yours may be telling you water pressure Low. But just a guess, it is hard to see from here. No model number don't help much either.


Good Luck on your project.
 

skasdan

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I would also.

I can not see a tankless lasting very long unless you have very Good filtered well water.


What is the model of this water heater ? How old is it ?


Good Luck on your project.

Thanks for responding. The heater is a Rinnai R75LSi. It's a couple of years old but has only actually been used for a little under a year (was purchased and installed but we only moved in around Thanksgiving of last year). Our well water is very clean - we only had the sediment issue after the new pump was installed. The sediment issue seems to have cleared up, thankfully. Now to check out the things mentioned here and see if we can get our hot water running reliably!
 

skasdan

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At least some on-demand water heaters slow the flow if they cannot keep up with the heating job rather than letting the output water go out lukewarm. If somebody were to know about your heater and recognize that, that person would have to know what water heater you have.

Regarding checking water pressure, I think you would want to check during a problem. But if there is no problem with the cold, the water pressure at the pressure tank must be OK. Incidentally, using 20-40 PSI water is unusual. 30-50 PSI and 40-60 PSI are more common.

I am glad to hear that you are saying the problem with the cold water is gone. It is not clear if the problem extends to the kitchen sink hot, or if it is just the bathroom hot. There are mixing valves and temperature regulating faucets. If one of those with a problem is in the path of your water, that might cause some complex behavior. So I think identifying the first thing in the water path that displays a problem would be useful. So while you have the bathroom problem, how does the hot in the kitchen behave?

Regarding sediment, why not add the filter even if the amount of sediment over time is going down? I would start maybe with something like the PENTEK-DGD-5005-20 filter element. Use polypropolyne filters, such as that, and not cellulose elements, on well water. If you do get such a filter, keep an extra O-ring on hand and use silicone grease on the O-ring when you re-use or replace the O-ring during a cartridge change. If the filter does not have that much sediment to deal with, that element would last for a year. Never put such a filter before the pressure switch.

Hi There,
The heater is a Rinnai R75LSi. Purchased a few years ago to install, but we just moved in and started using it just before Thanksgiving of last year. So it hasn't been used much at all, really. And this has been an issue ever since we moved in.
The issue does affect all of the faucets in the house. The same thing happens at the kitchen sink, washing machine, laundry room sink, bathroom sinks. Also, when it runs out in one location, nothing comes out in any of the other faucets, either. It doesn't happen as frequently with the kitchen or bathroom faucets as it does with the shower and the washing machine (it happens every time those things are used), but obviously there is not nearly as much hot water coming out at one time from the kitchen faucet or bathroom faucets as there is when the shower is washing machine is in use.
Every time I check the heater, there is no error code - just the usual temperature setting shows. I will try to experiment checking it when the issue occurs. Just really trying to pinpoint the most likely cause without having to disconnect or cut a bunch of pipes to find out! Since the cold water runs fine all the time, I am unsure where the problem is occuring. I'm not a professional by far - just someone who likes to try to figure things out without wasting money or time!
When you mention the possibility of a clogged pipe before the pressure gauge, do you mean the pressure gauge that is on the water pressure tank? Is there another one I should be looking for? Just making sure! Also, I believe our normal PSI is 30-60. I had written 20-40 before but honestly couldn't recall whether that was accurate at the time. I would have to double check to be certain.
 

skasdan

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We dealt with a customer recently who had a similar problem to yours, the cause was a hot water heater where one of the heating elements was broken, so any demand for hot water beyond a small amount caused the system to fail.

It would be helpful if you could put paragraphs in your writing, it is quite hard to read without them due to the way the forum bunches the text up.

Hope you get it sorted.
Hi, thanks for the tip - I see what you mean! I will try to remember to space my paragraphs out! Also, do tankless heaters have elements? I can check my manual :)
 

skasdan

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Gas heaters have a lot of safeties to keep from blowing yourself and your neighbors up.

That model should give you error codes.

Do you have the manual ?

http://www.rinnai.us/documentation/downloads/100000098_Water_Heater_Service_Manual_9-2008.pdf

If you do not understand what the manual says, you should get a Pro that does.


Good Luck.
Hi, thanks for writing. I have the manual and did go through it to see if I could do some troubleshooting but there are no error codes showing on the tank. If only there were - it would make figuring the problem out much easier! One member of the household did call Rinnai to try troubleshooting over the phone but the rep didn't seem to have much advice. I'm thinking another call would be worthwhile!
 

skasdan

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Hi, thanks for writing. I have the manual and did go through it to see if I could do some troubleshooting but there are no error codes showing on the tank. If only there were - it would make figuring the problem out much easier! One member of the household did call Rinnai to try troubleshooting over the phone but the rep didn't seem to have much advice. I'm thinking another call would be worthwhile!

Okay, here is one update to see if this narrows anything down. I tried an experiment while someone was in the shower. After about six or seven minutes the water did the usual slow down to a near trickle - interestingly, not as bad as usual but still very low pressure. While this was going on one person stayed with the hot water heater and pressure tank to see if anything showed up - error codes, etc. Even when the water in the shower receded, no error codes showed up nor did the pressure gauge indicated any loss of pressure!

Hoping maybe this will clarify a little.
 

FullySprinklered

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There is a switch which turns the well pump on and off. If it's stopped up, pressure can remain in the small tube which feeds it while the pressure tank empties, not allowing the pump to cycle on. After a while the pressure works it's way out through the stopage and the pump cycles on to restore the pressure. In my case it was rust.
 
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