I bought this water heater ruclips.net/user/postUgkx8G49mV71sAzUl9shXyLW-r3XgHH9EVh1 for use in my bus conversion. I installed it under my kitchen sink and it is fed by a high efficiency on-demand LP water heater. It is both a backup hot water source as well as a water saving device since we have hot water on demand rather than having to wait for the gas on demand water heater to finish its ignition cycle. I decided on this water heater due to the fact that it only draws 1300watts when it's ON instead of the 1500 watts that most Water heaters this size draw. In an RV a couple hundred watts can be a big deal. With very low standby losses, I don't have to worry about excessive power consumption. When propane is not available for our gas water heater, in conjunction with our low flow shower head there is enough hot water available to shower, albeit we won't be taking "hotel showers." Also very happy with the recovery rate of this water heater. Granted, it is quite small, but it does exactly what we need it to do.
Our Rheem unit, in our 2-person household, makes so little condensate that it evaporates out of a catch-bucket. No external drain is needed at this time. The condensate is alkaline (I tested it using 4 methods) - because our tap water is alkaline!
Yes, it's usually not a lot of condensate. Does your condensate drain come off of the side of the exhaust vent or does it come out of the bottom of the unit?
Good point, I'm check the brass fitting every year or two. In 7 years use, it has discolored a bit: photos.app.goo.gl/GeTSn1FSgLHnA6pFA I do have a PVC hose barb fitting ready to replace the brass fitting if it does spring a leak.
@@troyhough Good information on the lifetime you got. I may swap out that fitting then before it rots out so it's still useable as a spare for the PVC fitting I have. Only issue I find with with plastic is it seems to like to crack after some years, so having a ready spare is a good
I think you are a bit mistaken with your assessment of the Rheem 3-in concentric PVC vent. I installed one on my own Rinnai RUCS75IN. The middle pipe is for exhaust because exhaust naturally rises, making it escape faster. The outer layer that draws air from under the cone does so because that reduces drawing in rain water and debris. More importantly because the hotter exhaust gasses rise away from the roof, the intake is getting clean air from outside. The unit functions as to combine a 3-in intake and exhaust vent into one unit to reduce roof/wall penetrations. I used a 4" Oatey roof boot from Lowe's to cover the old B vent hole and put this through. Mastic and roofing nails and not a problem out of it. Just endured Hurricane Florence in NC without a leak. I kept the old drain pan in place from the tank water heater that was in the attic and drain the condensate to that. The pressure relief valve by code also has to have a pipe that puts it no more than 6" above the pan, the same as the condensate line. The IBC is not very well written for tankless water heaters, so best to follow codes even though they may not apply. A PRV on a tankless water heater is just silly. Also I believe the code says that tubing coming in of and out of the water heater must be metal at least 6 in from the intake/outlet couplings and the vent (also coded towards tank water heaters).
Great information on the concentric vent. I looked at the concentric vents but decided that separate intake and vent pipes would work best in my installation. My old tank type heater had no condensate drain and originally it had no drain pan either. I added one when I replaced the tank in 2000. The heater is in an unfinished garage. Agreed that the codes don't really cover tankless heaters that well, the PRV and also the expansion tanks specified in some areas.
Good point. The hose barb adapter I used is brass, which is listed as "Good" resistance to carbonic acid: www.dixonvalve.com/sites/default/files/downloadable_resources/product_literature/corrosion%20resistance%20chart.pdf I've been keeping an eye on the fitting and have procured a PVC replacement in case it starts to corrode. But in 5+ years, it still looks like the day it was installed.
Thanks for the video! I have a problem on my rinnai condensing water heater. I flushed it today and after doing it, even when heater is not running, there is a steady flow of water from condensing pipe. What to do to fix it. Thanks!
I'm not very familiar with the Rinnai heaters. You might try Mike at This Tankless Guy: ruclips.net/video/kfzmyMdYGL0/видео.html He's a Rinnai service tech. and really knows those units inside and out.
THE ISSUE I'M RUNNING INTO TRYING TO DO WHAT YOU DID IS UNDERNEATH THE UNIT I HAVE A HOLE WHERE YOUR COMPRESSION NUT ATTACHES TO UNIT ON MY QUIETSIDE I HAVE A HOLE THAT I WOULD NEED TO INSERT SOME KIND OF PIPE FITTING THAT WOULD THE CONNECT TO THE NUT AND THE REST OF THE SETUP YOU USED
You generally want the drain running in a downward direction to get the condensate water to flow away from the heater. Some installs have it running into a separate condensate pump, which might pump the liquid up to some other location. Others might run outdoors, or into a condensate neutralizer before going into a drain. You might also have a trap installed if the condensate line is directly connected to a drain pipe. On my install, the drain line runs into a washing machine stand pipe, via an air gap and there's a trap at the bottom of that stand pipe.
Is it normal for there to be a constant flow of water from the tankless heater into the drain pain which flows outside the house? (even when there has not been any hot water used in the house for a long time? Water is flowing like a faucet turned on low meaning much more than a drip)
If it's a condensate drain, then no, there should only be water dripping when the burner inside the heater is firing and the exhaust gas is condensing. Although some heaters apparently have small condensate tanks or neutralizers that may hold and slowly release water over time. It might be worth having the heater checked for leaks. One easy test would be to turn off the cold water supply to the unit and see if the drain flow stops. If so, there may be a leak someplace in the heater, maybe a loose connection or leak inside the heat exchanger.
Im having an issue with my on-demand water heater. Ever 5 or 6 weeks the condensation line will dump around 2 gallons of water into the floor pump tank i have setup and it runs over. The pump works fine but for some reason every 5 or 6 weeks it runs over. Do the on demand water heaters have a timed system purge? Any help is greatly appreciated.
No timed purge that I've heard of. You might check the condensate plumbing and see if something is amiss with it. Maybe there's a blockage, trap or neutralizer in the line that causes a bunch of liquid to back up into the heater then it lets go in one shot. My drain is a straight downward shot into a standpipe drain with a decent air gap between the drain line and the bottom of the drain pipe.
You did ok but, Way over thinking. It's not rocket science, just a drain. Your furnace condensates the whole time it's running. You could have used 5/8 hose. Warm the end up and slipped it over the 1/2" threads.
Thanks for the comment and suggestion. Yes, lots of ways to skin a cat, as they say. I wanted to stick with a relatively small dia. hose so I could slide in in along side the clothes washer drain tube into the existing standpipe. As-is, it was a tight fit. Nearly 2 years in and no issues with the condensate drain and being clear, I can see that water is flowing through it easily even running the heater full blast on a cold winter day. I wanted to show my research and calculations on sizing the drain hose I ended up using and that seems to be proven out in real life use.
I found this in the California Plumbing Code: "509.9 Condensation Drain Provision shall be made to collect and dispose of condensate from venting systems serving Category II and Category IV appliances and noncategorized condensing appliances in accordance with Section 509.8.3. [NFPA 54:12.10.1] 509.9.1 Local Experience Where local experience indicates that condensation is a problem, provision shall be made to drain off and dispose of condensate from venting systems serving Category I and Category III appliances in accordance with Section 509.8.3. [NFPA 54:12.10.2]" And this is what Takagi says: "CONDENSATE DRAIN • The water heater does not include a built-in condensate neutralizer cartridge for reducing the pH level of condensate water. If local codes dictate that condensate must be neutralized prior to drainage, a condensate neutralizer must be installed. An accessory Neutralizer assembly is sold separately. • In the absence of applicable local codes and regulations, the manufacturer recommends that condensate be disposed of into a standard drain. Connect a drain tube from the condensate drain port (shown below) located on the bottom of the water heater to a standard drain." I could not find any specific requirement for my city regarding the need for a neutralizer kit or anything special, I just did as the mfg. describes. Mine drains into a laundry drain, so the alkali detergent residue is supposed to help neutralize any acid in the condensate. The municipal water is at a pH of 7.8 - 8.1, so acidic condensate is not an issue locally.
The drain line drops into the clothes washer drain / standpipe which is just below it, you can see that at 4:30 in the video. So the condensate goes down the drain and any slight acidity is neutralized by the detergent and soap residues in that drain line. It's been working well for the last 20 months, no issues at all.
Sorry for the delay in replying, never got a notification for your comment. Yes, I suppose that might work, you would need to see how long it takes to fill up and make sure to set up an emptying schedule. Probably would not pass a plumbing inspection though. Or you can get a small condensate pump that has a catch tank and float and it'll fire up when the level in the tank gets high enough and pump the condensate to a drain: amzn.to/30DKmzu
Yes, used black iron pipe/fittings and a brass shutoff valve for the gas line. Still working great, coming up on 3 years since installation. The water lines are galvanized, same as the existing piping in the house.
Thanks for the quick reply. Not sure if that's code in my area or not, but mine would be going in garage as well not too far from existing tank water heater. Current water heater has a line through the wall that exists outside for the pressure relief. I still need to research code, but thinking I can try to plumb back through that if it's not too much trouble.
My old tank TPR pipe dropped down to the garage floor as well. However, it was not done to modern code as it had a 3/4"-1/2" reducer and 1/2" drain pipe along the tank.
It depends on how you look at it. In raw form, lemon juice has a pH falling between 2 and 3, which makes it 10,000-100,000 times more acidic than water. However, like other fruits, lemon juice produces alkaline byproducts once it has been consumed and metabolized. Therefore, it has a negative PRAL score: www.healthline.com/nutrition/lemon-juice-acidic-or-alkaline#section2 And here's a video where I check the pH of the tankless condensate: ruclips.net/video/YjhLNgUETXQ/видео.html
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Timeline:
0.10 Commercial condensate drain options
1:40 Concentric vent kit
2:10 Volume of condensate
4:29 Condensate drain location
5:38 Brass condensate hose adapter
7:24 Nylon condensate hose adapter
7:45 Condensate hose in action
9:30 Condensate stops
I bought this water heater ruclips.net/user/postUgkx8G49mV71sAzUl9shXyLW-r3XgHH9EVh1 for use in my bus conversion. I installed it under my kitchen sink and it is fed by a high efficiency on-demand LP water heater. It is both a backup hot water source as well as a water saving device since we have hot water on demand rather than having to wait for the gas on demand water heater to finish its ignition cycle. I decided on this water heater due to the fact that it only draws 1300watts when it's ON instead of the 1500 watts that most Water heaters this size draw. In an RV a couple hundred watts can be a big deal. With very low standby losses, I don't have to worry about excessive power consumption. When propane is not available for our gas water heater, in conjunction with our low flow shower head there is enough hot water available to shower, albeit we won't be taking "hotel showers." Also very happy with the recovery rate of this water heater. Granted, it is quite small, but it does exactly what we need it to do.
Our Rheem unit, in our 2-person household, makes so little condensate that it evaporates out of a catch-bucket. No external drain is needed at this time. The condensate is alkaline (I tested it using 4 methods) - because our tap water is alkaline!
Yes, it's usually not a lot of condensate. Does your condensate drain come off of the side of the exhaust vent or does it come out of the bottom of the unit?
Only use plastic fittings on the condensate. Trust me I learned the hard way 😂
Good point, I'm check the brass fitting every year or two. In 7 years use, it has discolored a bit:
photos.app.goo.gl/GeTSn1FSgLHnA6pFA
I do have a PVC hose barb fitting ready to replace the brass fitting if it does spring a leak.
@@The4Crawler it took mine about 12 years to eat through FYI. thanks for making the video!
@@troyhough Good information on the lifetime you got. I may swap out that fitting then before it rots out so it's still useable as a spare for the PVC fitting I have. Only issue I find with with plastic is it seems to like to crack after some years, so having a ready spare is a good
@@The4Crawler I don't think it will ever crack unless it's overtightened or there is unnecessary strain.
I think you are a bit mistaken with your assessment of the Rheem 3-in concentric PVC vent. I installed one on my own Rinnai RUCS75IN. The middle pipe is for exhaust because exhaust naturally rises, making it escape faster. The outer layer that draws air from under the cone does so because that reduces drawing in rain water and debris. More importantly because the hotter exhaust gasses rise away from the roof, the intake is getting clean air from outside. The unit functions as to combine a 3-in intake and exhaust vent into one unit to reduce roof/wall penetrations. I used a 4" Oatey roof boot from Lowe's to cover the old B vent hole and put this through. Mastic and roofing nails and not a problem out of it. Just endured Hurricane Florence in NC without a leak. I kept the old drain pan in place from the tank water heater that was in the attic and drain the condensate to that. The pressure relief valve by code also has to have a pipe that puts it no more than 6" above the pan, the same as the condensate line. The IBC is not very well written for tankless water heaters, so best to follow codes even though they may not apply. A PRV on a tankless water heater is just silly. Also I believe the code says that tubing coming in of and out of the water heater must be metal at least 6 in from the intake/outlet couplings and the vent (also coded towards tank water heaters).
Great information on the concentric vent. I looked at the concentric vents but decided that separate intake and vent pipes would work best in my installation. My old tank type heater had no condensate drain and originally it had no drain pan either. I added one when I replaced the tank in 2000. The heater is in an unfinished garage. Agreed that the codes don't really cover tankless heaters that well, the PRV and also the expansion tanks specified in some areas.
Great Job and good info. Thank you
Thanks for watching!
Condensate being acidic, I don't think you're supposed to use copper fittings?
Good point. The hose barb adapter I used is brass, which is listed as "Good" resistance to carbonic acid:
www.dixonvalve.com/sites/default/files/downloadable_resources/product_literature/corrosion%20resistance%20chart.pdf
I've been keeping an eye on the fitting and have procured a PVC replacement in case it starts to corrode. But in 5+ years, it still looks like the day it was installed.
Thanks for the video!
I have a problem on my rinnai condensing water heater. I flushed it today and after doing it, even when heater is not running, there is a steady flow of water from condensing pipe. What to do to fix it. Thanks!
I'm not very familiar with the Rinnai heaters. You might try Mike at This Tankless Guy:
ruclips.net/video/kfzmyMdYGL0/видео.html
He's a Rinnai service tech. and really knows those units inside and out.
THE ISSUE I'M RUNNING INTO TRYING TO DO WHAT YOU DID IS UNDERNEATH THE UNIT I HAVE A HOLE WHERE YOUR COMPRESSION NUT ATTACHES TO UNIT ON MY QUIETSIDE I HAVE A HOLE THAT I WOULD NEED TO INSERT SOME KIND OF PIPE FITTING THAT WOULD THE CONNECT TO THE NUT AND THE REST OF THE SETUP YOU USED
should the drain be pointing towards the ground?
You generally want the drain running in a downward direction to get the condensate water to flow away from the heater. Some installs have it running into a separate condensate pump, which might pump the liquid up to some other location. Others might run outdoors, or into a condensate neutralizer before going into a drain. You might also have a trap installed if the condensate line is directly connected to a drain pipe. On my install, the drain line runs into a washing machine stand pipe, via an air gap and there's a trap at the bottom of that stand pipe.
Is it normal for there to be a constant flow of water from the tankless heater into the drain pain which flows outside the house? (even when there has not been any hot water used in the house for a long time? Water is flowing like a faucet turned on low meaning much more than a drip)
If it's a condensate drain, then no, there should only be water dripping when the burner inside the heater is firing and the exhaust gas is condensing. Although some heaters apparently have small condensate tanks or neutralizers that may hold and slowly release water over time. It might be worth having the heater checked for leaks. One easy test would be to turn off the cold water supply to the unit and see if the drain flow stops. If so, there may be a leak someplace in the heater, maybe a loose connection or leak inside the heat exchanger.
Im having an issue with my on-demand water heater. Ever 5 or 6 weeks the condensation line will dump around 2 gallons of water into the floor pump tank i have setup and it runs over. The pump works fine but for some reason every 5 or 6 weeks it runs over. Do the on demand water heaters have a timed system purge? Any help is greatly appreciated.
No timed purge that I've heard of. You might check the condensate plumbing and see if something is amiss with it. Maybe there's a blockage, trap or neutralizer in the line that causes a bunch of liquid to back up into the heater then it lets go in one shot. My drain is a straight downward shot into a standpipe drain with a decent air gap between the drain line and the bottom of the drain pipe.
@@The4Crawler thanks man. At least that gives me a direction to start looking. Its driving me nuts.
Just tell me where to drain it at.
First line of the video description:
"Setting up a drain tube for the condensate out of the tankless water heater to the existing laundry drain."
You did ok but, Way over thinking. It's not rocket science, just a drain. Your furnace condensates the whole time it's running. You could have used 5/8 hose. Warm the end up and slipped it over the 1/2" threads.
Thanks for the comment and suggestion. Yes, lots of ways to skin a cat, as they say. I wanted to stick with a relatively small dia. hose so I could slide in in along side the clothes washer drain tube into the existing standpipe. As-is, it was a tight fit. Nearly 2 years in and no issues with the condensate drain and being clear, I can see that water is flowing through it easily even running the heater full blast on a cold winter day. I wanted to show my research and calculations on sizing the drain hose I ended up using and that seems to be proven out in real life use.
Does anyone know if the plumbing codes require anything special with the condensate drain for tankless water heaters?
I found this in the California Plumbing Code:
"509.9 Condensation Drain
Provision shall be made to collect and dispose of condensate from venting systems serving Category II and Category IV appliances and noncategorized condensing appliances in accordance with Section 509.8.3. [NFPA 54:12.10.1]
509.9.1 Local Experience
Where local experience indicates that condensation is a problem, provision shall be made to drain off and dispose of condensate from venting systems serving Category I and Category III appliances in accordance with Section 509.8.3. [NFPA 54:12.10.2]"
And this is what Takagi says:
"CONDENSATE DRAIN
• The water heater does not include a built-in condensate neutralizer cartridge for reducing the pH level
of condensate water. If local codes dictate that condensate must be neutralized prior to drainage, a
condensate neutralizer must be installed. An accessory Neutralizer assembly is sold separately.
• In the absence of applicable local codes and regulations, the manufacturer recommends that
condensate be disposed of into a standard drain. Connect a drain tube from the condensate drain port
(shown below) located on the bottom of the water heater to a standard drain."
I could not find any specific requirement for my city regarding the need for a neutralizer kit or anything special, I just did as the mfg. describes. Mine drains into a laundry drain, so the alkali detergent residue is supposed to help neutralize any acid in the condensate. The municipal water is at a pH of 7.8 - 8.1, so acidic condensate is not an issue locally.
What about an air gap?
Good question. There's an air gap inside the standpipe. It's a good 4 feet down to the p-trap at the bottom of that drain pipe.
Where does this condensate end up going?
The drain line drops into the clothes washer drain / standpipe which is just below it, you can see that at 4:30 in the video. So the condensate goes down the drain and any slight acidity is neutralized by the detergent and soap residues in that drain line. It's been working well for the last 20 months, no issues at all.
R Brown would it be possible to have this condensate drain drip from a hose into a bucket or something? If a drain isn’t nearby
Sorry for the delay in replying, never got a notification for your comment.
Yes, I suppose that might work, you would need to see how long it takes to fill up and make sure to set up an emptying schedule. Probably would not pass a plumbing inspection though.
Or you can get a small condensate pump that has a catch tank and float and it'll fire up when the level in the tank gets high enough and pump the condensate to a drain:
amzn.to/30DKmzu
Don't use the galvanized pipe on gas lines.
Yes, used black iron pipe/fittings and a brass shutoff valve for the gas line. Still working great, coming up on 3 years since installation. The water lines are galvanized, same as the existing piping in the house.
Our plumber used galv pipe for all our gas lines during a repipe.
Where did you plumb your pressure relief valve to?
I used a 3/4" PEX TPR drain tube that drops down to about 6" off the garage floor, behind the clothes washer.
Thanks for the quick reply. Not sure if that's code in my area or not, but mine would be going in garage as well not too far from existing tank water heater. Current water heater has a line through the wall that exists outside for the pressure relief. I still need to research code, but thinking I can try to plumb back through that if it's not too much trouble.
My old tank TPR pipe dropped down to the garage floor as well. However, it was not done to modern code as it had a 3/4"-1/2" reducer and 1/2" drain pipe along the tank.
Lemon juice isn't acidic.. It's alkaline
It depends on how you look at it. In raw form, lemon juice has a pH falling between 2 and 3, which makes it 10,000-100,000 times more acidic than water.
However, like other fruits, lemon juice produces alkaline byproducts once it has been consumed and metabolized. Therefore, it has a negative PRAL score:
www.healthline.com/nutrition/lemon-juice-acidic-or-alkaline#section2
And here's a video where I check the pH of the tankless condensate:
ruclips.net/video/YjhLNgUETXQ/видео.html
work on the house is never done good job
Yes, you got that right!