cantbreak80
Maybe I need new clubs
The threaded plug on top of the tank is not tightened...it's just installed with 1-2 threads...just to keep debris from contaminating the glycol.
Another tankless water heater replacing boiler thread
- Thread starter OurTown
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OurTown
Well-known member
I assume he means open to the atmosphere because that is still a closed loop.
OurTown
Well-known member
Ours has a pvc pipe coming out and a 180 degree turn down to prevent dirt entry.
Makes sense, thanks!
OurTown
Well-known member
I am old enough now that I'm starting to get skeptical of that saying.
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After looking at the spec sheet for the CU199iN, I would think you would need a backup water supply to your hot gravity tank like you mentioned...Also did you see a minimum water supply pressure of 50psi? Recommended 60-80psi.....At a 60° delta, you are looking at 6gpm output rating...I forget how many bays you have? If you are running a softener, you'd need to know what your pressure is after the softener, since it creates head pressure. One thing missing from their flow chart is water pressure. Water pressure has a direct effect on output gpm....To get the advertised 11gpm, I'm thinking you would have to supply it with 150psi pressure. In their warning note, they are substituting "Altitude" for pressure! All three affect final output flow in gpm.
I know I have quite a bit of head pressure in my 1" Fleck softener, about 15-20 psi drop across the softener which is the spec. We had a main break in town that wasn't filling the towers. So pressure dropped to about 30psi coming in to my wash...I had to add an additional water supply (hydrominder, its all I had) to my cold gravity tank and plumb it from in front of my softener. Without it, when all 4 bays were running HP, I would run out of water in my gravity tanks (10gal each) in just a few minutes. Plumbing in water from ahead of my softener was enough to keep the gravity tanks happy! I know I could have bypassed my softener, but this works too. At a normal 45 psi incoming pressure, I am good to go running 100% through the softener. So all things to consider when sizing things up to work the way you want them too.
My 1" softener is marginal for my 4bay because of the head pressure resistance and flow rates. With a 1" service, I should get 40 gpm, but since the softener is only rated at about 20gpm, that makes my system marginal....I have a 1.5" Fleck 9500 and all 1.5" plumbing that I need to install! It would give me double the capacity and margin of error....A pretty big job I'm not wanting to take on in the middle of winter!
cantbreak80
Maybe I need new clubs
I did some recent service at a location where the tank's plug was replaced with a 1 lb coffee can.
I looked like it was original equipment...from 1985.
BTWW, if anybody has a different opinion on what I stated, please feel free to elaborate. Its just how I interpret flow rates, pressure , and head pressure restriction on any given pipe size or valve.
OurTown
Well-known member
2" water meter and 2" softener piping. 52 PSI after the meter and 42 PSI after the backflow preventer. 18 PSI drop when the touchless auto was running but I thought that was due to the resin going bad. So what would happen if this tankless water heater was installed? Not run at all? Not have any flow until 50+ PSI? What if someone's house was on a well? Mine has a pressure switch set between 40 and 60 which is typical but some have a 30-50 PSI switch.
Good questions and ones that might be better answered by an Engineer from Rinnai?? My Takagi is a T-H3-DV-N 199btu...Water pressure is from 15-150...The manual does say to get maximum flow you need a minimum of 40 psi, and flow is based on setpoint, delta temp rise, and incoming water temp. With 40psi from the two pumps, I get 6.0gpm flow at 105° set point and about 50° rise.
Unless you spring for a true wall mount boiler like a Lochinvar or Triangle Tube, flow rates will be restricted. But price also goes way up! There is a definate difference in the designs!
Not quite the way I remember it!!! See link below and post #27 is where I mention cleaning the system and the small filter screen in the Takagi...I did not replace the filter screen with anything bigger...I just cleaned it and reinstalled it. What I did was put a 5 micron filter inline using the 2 service ports and a sump pump in a 15 gallon barrel to filter the zones..I ran the main zone pump, the sump pump, and 5 micron filter for 24 hours without running the heater. No glycol was circulating through the heater while I was cleaning the zone loops. That was 12 years ago...I haven't had to do anything to the small filter screen since...Still get the same 6GPM through the heater as I did 12 years ago.
(26) Tankless Water Heater For Floor Heat | Page 2 | Car Wash Forum
Not quite the way I remember it!!! See link below and post #27 is where I mention cleaning the system and the small filter screen in the Takagi...I did not replace the filter screen with anything bigger...I just cleaned it and reinstalled it. What I did was put a 5 micron filter inline using the 2 service ports and a sump pump in a 15 gallon barrel to filter the zones..I ran the main zone pump, the sump pump, and 5 micron filter for 24 hours without running the heater. No glycol was circulating through the heater while I was cleaning the zone loops. That was 12 years ago...I haven't had to do anything to the small filter screen since...Still get the same 6GPM through the heater as I did 12 years ago.
(26) Tankless Water Heater For Floor Heat | Page 2 | Car Wash Forum
Not quite the way I remember it!!! See link below and post #27 is where I mention cleaning the system and the small filter screen in the Takagi...I did not replace the filter screen with anything bigger...I just cleaned it and reinstalled it. What I did was put a 5 micron filter inline using the 2 service ports and a sump pump in a 15 gallon barrel to filter the zones..I ran the main zone pump, the sump pump, and 5 micron filter for 24 hours without running the heater. No glycol was circulating through the heater while I was cleaning the zone loops. That was 12 years ago...I haven't had to do anything to the small filter screen since...Still get the same 6GPM through the heater as I did 12 years ago.
(26) Tankless Water Heater For Floor Heat | Page 2 | Car Wash Forum
Thanks for reminding me. The cleaning of the loops was ongoing until you were satisfied it was good. What solution did you find for the cleaning? I will reread the oldpost but want to thank you for documentation that you have done.Not quite the way I remember it!!! See link below and post #27 is where I mention cleaning the system and the small filter screen in the Takagi...I did not replace the filter screen with anything bigger...I just cleaned it and reinstalled it. What I did was put a 5 micron filter inline using the 2 service ports and a sump pump in a 15 gallon barrel to filter the zones..I ran the main zone pump, the sump pump, and 5 micron filter for 24 hours without running the heater. No glycol was circulating through the heater while I was cleaning the zone loops. That was 12 years ago...I haven't had to do anything to the small filter screen since...Still get the same 6GPM through the heater as I did 12 years ago.
(26) Tankless Water Heater For Floor Heat | Page 2 | Car Wash Forum
If I'm not mistaken, I bought the System Pre-Cleaner in the link below. I also bought the Noburst glycol from this company....
OurTown
Well-known member
I'm back on this project. Are you saying that if using two heaters the two pumps should be in series and then split off to each heater inlet? Or do you think there needs to be two pumps per heater? I'm still trying to figure out pump sizing on the primary loop.
OurTown
Well-known member
If I use the old buffer tank and run it vented on top will I need a larger pump to circulate the secondary loop? Will this introduce oxygen into the system? It was vented before and used a cast iron pump, but that does not necessarily mean it is okay. I should not need an air eliminator or an expansion tank, correct?
