Rinnai tankless woes

Jack

Below 68 it fails, but a light bulb solves it? What model? If a condensing model are you getting condensate in the base pan, I think. If so that is a leak protection system which shuts off the water supply to prevent damage. Have you called tech service at 800 621-9419 for assistance?

Supernewf71

thanks. will call that number and see what they say. i have not called anyone yet.

icesailor

"" Also, Ice, as the rep (in another life), it was not uncommon to meet a guy on a job site and he would not have any diagnostic tools. He saw no need for them. He had my number. There were some interesting conversation there. I had one young plumber call me and tell me to go see his customer who was having a problem with a Rinnai he had just installed. I told him I'd meet him there. He said, "no you go do it." He wasn't interested in learning about them. He said, "I do pipe." After I went out and repaired the install with a good guy, I called the kid back and told him he is to young to think he can make a living "doing pipe", Especially so as he was clueless about proper lay-out. It was fun! We agreed that he would only install my competitors lines from then on. "I do pipe." Honestly, I'm still amazed! ""

I've met that guy. I lost a few jobs to him but I was dumb enough to sometimes go back and fix it for his former customer.

mikey32230

icesailor said:

"" Also, Ice, as the rep (in another life), it was not uncommon to meet a guy on a job site and he would not have any diagnostic tools. He saw no need for them. He had my number....

@ JACK or ICE,

I have a Rinnai r53 Plus water heater. We have had it recently cleaned an inspected in the summer, and it has worked find for months. However, now that it has become extremely cold outside the unit is running into more problems. It only acts up when it is extremely cold outside, i'm not sure if they is a sensor problem because the unit is sucking in freezing cold air, or because it sits on a cold wall in the basement?

The symptoms of the problems are when taking a shower, they water pulsates between very hot and cold temperatures. The infamous cold water sandwich.

Is there any suggestions you guys may have? Like i said the fans should all be clear, I don't see any condensation in the little clear tube that returns to the gas valve.

Any help is appreciated. Thank you!

Jack

I would look first at the turbine in the cold water inlet valve. If that turbine is not spinning freely the unit will not work. Everything follows it.

mikey32230

Jack said:

I would look first at the turbine in the cold water inlet valve. If that turbine is not spinning freely the unit will not work. Everything follows it.

Okay we have checked the turbine and it seems to be spinning freely.

The cold water sandwhich probably started the day it got very cold. Is there any common issues due to temperature? Or any next steps to take in troubleshooting?

Jack

If it is a 53 it has been installed for several years, yes? It has worked in cold temps during that time. This is going to require a bit more diagnostic. Call the 800 number on the side of the unit. What error code is it throwing? Look at your install manual and have the unit dump the error code history.

mikey32230

null
Yes it is a an r53. It has worked fine in the past but in recent years every winter we have this problem. It does not throw any error codes. It works fine we manage to take showers fine but it gets hot and cold.

We have had plumbers in to look at it, it is out of warranty so rannai doesn't do anything, they do it all through the plumber. We have dealt with error codes in the past that have been resolved. This problem however does not give any errors.

mikey32230

Jack said:

If it is a 53 it has been installed for several years, yes? It has worked in cold temps during that time. This is going to require a bit more diagnostic. Call the 800 number on the side of the unit. What error code is it throwing? Look at your install manual and have the unit dump the error code history.

Ok this is what we have done / observed.

- Turned off cold water supply to the heater and opened the hot water ball valve at the unit, emptying the system.
- Cleaned filter. During this we noticed that when the washing machine water shut off, there was a back surge through the heater. I recall always hearing the unit briefly turn on and off during the washer cycles. Possibly a separate problem.
- With everything back together I tested hot water by turning on the hat water ball valve at the unit. The system ran smoothly – no problems.
- I then tried our second story shower (heater in basement). Once again we got the temperature flux – flame increase / flame decrease / flame increase etc… The flame does not go out.
- Also, you should be aware that during hard driving rains, we do get water dripping down into the heat exchanger and months ago found water in a clear plastic line that appears to go from the heat exchanger to the gas assembly. No water in that line at this time.

icesailor

What kind of shower valves do you have? How old are they?

There is one older type of single lever valve that has a pressure balancing spool on the "outside" of the control cartridge. In other words, although the valve is off, there can still be a direct cross connection between the hot and the cold water. That surge that appears from the washing machine can be a sign of a cross connection. Good luck finding someone that understands how to find it.

If you go into a bathroom and turn a sink faucet on and off, and hear a click behind the tub or shower, you might have that kind of valve.

Jack

If you are getting water back into the unit the vent is not installed correctly. It must grade to the outside. There is a drain in the vent termination that should be connected to relieve any moisture coming back to the unit. My concern here is that if you have had moisture coming back over an extended period it can seal up the fins on the HX. That is a problem!

If the unit runs well drawing hot water at the hot outlet of the unit, the R53 is functioning correctly. i suspect that you have a system issue. I think!

AllenP

Hi Jack, I have a strange problem with our Rinnai tank-less water heating system. This will be the second winter season that the water flow goes from hot to cold then hot then cold again, cycling back and forth. We have a R75LS system, and has been in operation for about 4 years now. There are no error messages on the front display, and we have it set at 125 degrees. Any thoughts on why this the hot and cold cycle like this?

mikey32230

AllenP said:

Hi Jack, I have a strange problem with our Rinnai tank-less water heating system. This will be the second winter season that the water flow goes from hot to cold then hot then cold again, cycling back and forth. We have a R75LS system, and has been in operation for about 4 years now. There are no error messages on the front display, and we have it set at 125 degrees. Any thoughts on why this the hot and cold cycle like this?

@AllenP‌

If you are talking about specifically your shower, We actually had the same issue. It seemed to appear during winters much like you are describing..

It turns out that the solution was to use a new showerhead. I still don't understand why that solves the problem, but it does. Maybe jack or ice can speak more about what the showerhead has to do with solving the issue.

AllenP, I would try first removing your shower head and then let the water run out like normal and see if it still produces the cold water sandwhich effect. If it works as it should, go get yourself a new showerhead.

Good luck!

AllenP

Thank you. i will give that a try first.

j a_2

Is the heater sized correctly…sometimes they show there ugly side when undersized and the ground water temp changes…Has it been serviced?

AllenP

Hi j a, I haven't had it serviced yet. Also, I'm sure how to tell if it's undersized or not. Any suggestions?

j a_2

If you will go to the Rinnai web site there is a very user friendly sizing chart….First questions tech will ask if you call will be what is the code, what is gas pressure…When and if you call be sure to get a control number…..I assume it was installed correctly, otherwise its very hard to help,site unseen….Goodluck

Jack

Error codes are held in memory. There may be codes that are not showing. Get your manual out and it will tell you how to dump the error code history is there are any. Get your shower running and read the flow rate on the display(. That is the same unit I have here at home and has a minimum flow rate of .4 gpm to initiate operation and should hold flow down to .25 gpm. If you consider that your max shower temp is 110, I suggest you turn the unit down to 120. I run mine at 115 in the summer and 120 winter.

With a tank water heater, if you want more capacity you turn the temp up so you have more hot water to mix down to use temps. A tankless is better at the lower temp settings as it increases the mix of H/C. Let's say you have a low flow shower head (1.5gpm). If you run high hot water temps you decrease the amount of hot needed to deliver the desired shower temp. Sometimes I have seen that hot side so low that the unit cycles on/off.

After 4 yrs, the unit should be flushed. 4-5 gal of white vinegar pumped through the service valves. Put an old silk stocking or nylon stocking on the return and check to see if any crap is coming out. And, btw, I need to follow my own advice and do mine;)

Once you get the flow from the shower when it is running as you like, shut off the hot to the building, connect a hose to the hot service valve and run the unit again. Using the ball valve handle on the service valve cycle it down to the same flow rate as the shower. Does it maintain operation? Not sure how Allen's problem was fixed by a new shower head, but many shower issues have been fixed by a new shower cartridge.

icesailor

If you run the hot water side to a pressure balanced shower valve, you can overcome the safety side of the valve. There are some older single lever, pressure balance shower valves that are really bad. A dirty HX is usually a bigger culprit. The cold in the shower comes from the gas valve cycling because the HX overheats and shuts off.

A clean HX is a happy HX.

Just like a long haired teenager with clean hair.

mayna123

Can anyone share their opinions on a disagreement we are having on installing a Continuum R75 water heater. The install instructions say the vent should be installed pitched to the water heater in cold climates; which means adding a system to drain the condensate. What constitutes a cold climate? Are most other installers installing the vent so it is pitched down to the heater or to the termination on a typical 12" horizontal vent length?

Jack

I have always wanted the non condensing vent going to the outside. BUT, that depends upon the configuration of the vent. Is it a straight 90 and out or a long vent with 90's/45's. What's the vent look like?

mayna123

It is a single 90 from the top of the heater then through the exterior with a 12-18" section.

Jack

I ALWAYS grade that to the outside. Set the 90 as the high point. Rinnai shows one drawing in the install manual that has the condensate line piped and they show the vent grading all the way up to the outside, even the termination piece. Even if a system required that kind of lay-out I never grade the termination up on the 75/94 units. I do not mind condensate from the vent coming back to a unit that has its condensate line piped, but I do not want the vent termination to turn into a rain water leader. On systems that require a long run with condensate a likely by-product I'd consider going to the condensing models

mayna123

Jack,
Thank you so much for your input! I was using common sense and others are using the 'should' as 'shall' and making a big deal out of nothing. (should pitch towards heater when installed in cold climates). I think I can put this issue to rest now with our company.

DrGrafix

I got a surprise a couple of days ago on my R94Lsi tankless when nothing but cold water came out in the shower. Checked unit, Code 12, saw the flame igniting but shutting down in 20-30 seconds so I called my installer. He knows I'm fairly competent mechanically, so he suggested removing the manifold plate and blowing out the jets. Powered down, shut off gas, opened cover, did a quick vacuum of the interior with a computer vacuum attachment for the nooks and crannies, then removed plate, blew it out with 100psi compressor. Reassembled, got a Code 61 so I blew some air into the fan connector and a few drops of moisture blew back out. So I did it until nothing came out, then let it sit open for an hour or so. Powered it back up and fan was "groaning" a little (original fan failed last year), so I unplugged again, removed rubber boot and spun the fan with my fingers a few times. Powered up and the fan kicked in but not full RPM then it stalled. Did this a couple times and then the fan spun up like it normally does. Put the boot back on, and no codes, plenty of hot water. I had recently (30 days ago) flushed with 4 Gallons of distilled white vinegar, it didn't turn super dark, more of a mint green. I wondered if flushing had anything to do with it. My installer had suggested cleaning the "rod" with a dollar bill, cautioned about not using sandpaper, but he never got to text me where this rod was or how to access it. I looked on the website but nada. One other precaution I took was I drilled a few 1/4" holes in the bottom of the intake/exhaust PVC pipe to ensure that moisture or driving rain doesn't puddle in there. Was that OK? -Mike

Jack

The pvc you drilled is on the combustion air side, so you should be ok. You should not be getting moisture back Through either the exhaust or intake. How is the unit terminated? You must be pulling in a lot of...crap...to be loading up the inducer that much. Every system has a personality, but if this, as it sounds is a recurring theme on the fan getting dirty you need to look and see if there is a better area for the termination of the vent. Easy for me to say, eh? When you had the face plate off, did you see any green discoloration on the copper fins over the area where the flame rod and sparker are? that would indicate moisture getting back through the vent and into the HX. Not good. If so, pipe the condensate line on the rt side of the vent connector on the top of the unit. Be sure to trap it if you do.

Years ago Rinnai had a guy in the NE doing technical training. His name was Jim and he was all tatted up gruff kinda quintessential Harley guy. A fine one at that. He got pulled down to FL to do some classes and one of the guys n the class had a unit close by that he couldn't fix. Jim when out with him and pulled that rubber boot off the inducer. He said a lizard about 8" long ran right up his arm. He said, "I screamed like a little girl. I didn't know that sound could come out of me." He's gotten a lot of mileage out of that story and I get a good laugh out of it every time I think of him.

DrGrafix

Jack... You'd have to explain what you mean by how the unit is "terminated". The I/E stack comes out of the unit, does a single 90˚ and exits through the clapboard about 30" or so if thats what you meant. And its a pipe within a pipe... looks pretty standard, probably 30" off the ground, nothing but a mulch bed under it.

The only plate I had off was what I'd call the manifold cover, its the one with the black rubber/silicon seal on one side, covers the venturi type ports, the uppers seemed smaller than the lowers. Never really got to see any "fins" although I think the upper part was copper like a tank? There were a few minor water stains in there, don't know if they were leftovers from the last time or not because the fan died because of moisture, but it was out of warranty. I did notice that there's a little weep hole at the bottom of the fan cage.

That story is/was funny. Me? Not biker any more LOL... but I'm still a senior hot rodder!

Shell77

We have a Rinnai R53. We've owned our home for two years--it came with the home. It's our first tankless system. We've had no problems with it until this season. We were getting a code 12 after a heavy snow and realized the exhaust was covered. We dug it out and it worked fine for several weeks but a few days ago it started to give a code 11. We restarted it a couple of times and it worked fine. This morning after attempting to run hot water unsuccessfully we went down to the basement and found water pouring out from the bottom of the unit. We had a very cold night last night (-42 windchill). We've phoned a service rep for maintenance and are awaiting a call back. My question is this--is the water pouring out related to a possible freeze in a pipe or exhaust or a dirty filter--or something more ominous. Thanks much!

Update--I took the front panel off to dry out, turned the water and unit back on and tried the hot water again to see if I could tell where the leak was coming from. It shoots water from the top portion of the unit. Is this a heat exchanger problem?

John_nh

Hi Jack. I appreciate what your doing here. It's very helpful. I was hoping you might be able to help me as well. I have a rinnai e110cp. I don't have any error codes but it won't produce hot water. It has an operation code 6 which says burner off while thermostat is calling but there are none turned on. The heat works fine right now just no hot water. I also noticed with an operating code of 0 the exhaust fan is still running. It's 13 degrees outside so i wasn't sure if that was a safety thing. Thank you.

RobG

Can everyone please just start a new post with your issues? It will make it allot easier to answer questions.

Jack

John, There is a 3-way valve and a paddle switch on the unit that must "make" in order for the unit to make hot water. Verify the position of the lever on the 3 way in heat mode and then when running hot water see if the lever moves. As well, about 4-6" up the line towards the plate hx is a black (the perfect color to make it almost invisible) paddle switch that also has t o make for it to run.

Jack

I'm tired of scrolling through this thread. It began in 2010. Anyone who wants can keep it going may do so, but I am DONE WITH IT!