Questions tagged [tankless]
A tankless water heater directly heats water on demand, instead of maintaining a reservoir of hot water. Use this tag in conjunction with the [water-heater] tag
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Can I feed a mini, tankless hot water heater from an ultrafiltration water filter system?
I've just been diagnosed with a ubiquitous pulmonary bacteria called MAC commonly found in tap water and that requires a 0.2 micron filter. It's smaller than other bacteria and treatment is long and ...
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Rheem KW-18 tripping breaker
I installed a Rheem KW-18 tankless water heater in the house 3-4 years ago. I have never had an issue other than the lights will blink when the water heater is running. We adjusted to that and it's no ...
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Tankless gas water heater exhaust pipe
I installed a tankless gas water heater about 18 months ago. I used polypro for the exhaust pipe as I understand the MA code to require.
The polypropylene exhaust pipe extends something like 12 inches ...
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Best solution for undersized wire/breaker?
I’m installing a Stiebel Eltron 24kW electric tankless water heater in my garage which requires two 50A breakers and 6/2 wire. I have a 200A sub panel located in the same garage (Siemens G3040L1200CU)...
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What size breaker box am I going to need?
I would like to use a Smith Four chamber electric tankless water heater it requires 240 V 60 A each on two circuits. Recommended wire size is six it will be located less than 20 feet away from the ...
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Tankless water heater help
I just bought a tankless water heater for my house and removed my old tank water heater. I did note that with my new heater, it takes 4 wires my old tank only took one wire.
I'm not an electrician and ...
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Sizing recirculating pump for water heater return line
Edit: According to Rinnai, the minimum flow rate is 0.26 GPM.
I just replaced an old water heater tank with a Rinnai RU199 tankless unit. A dedicated 1/2 return line was ran through the attic to the ...
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Tankless water heater in line with building hot water
Will a tankless water heater at a bathroom sink on the hot water line shut off once the hot house hot water reaches it?
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Should I replace two 75-gallon (gas) water heaters in series with a tankless heater?
We live in the Midwest in a large home that was built 20 years ago. At the time, we installed two 75-gallon gas water heaters, and the plumber did this in series, not parallel. We also have a system ...
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Under-sink tankless water heater inlet
I'm looking at installing a mini water heater under my kitchen sink for quick usage. I already have a whole- house tankless water heater in my basement.
I'm trying to avoid having the main unit kick ...
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Is this temperature and pressure release piping up to code?
I just finished installing this Rennai natural gas tankless heater yesterday, and it's working well.
My only question is I'm wondering that if I ever get it inspected, will this T&P release piping ...
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Where can I place a direct vent termination location for water heater?
Location: U.S.
I'm trying to figure out all of the clearance distances requirements and looking for the best place to vent a new direct vent water heater. As you can see by the image, the existing ...
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Is it ok to plug my 240v tankless water heater directly into a 50 amp RV plug instead of putting it on two 30 amp breakers
I live in an RV and am trying to install an electric tankless water heater by myself. It says it requires 2 double pole 30 amp breakers which is not really an option for me, the manual says the heater ...
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Is Crossover Hot Water Recirculation a Good Choice for Branch-Type Piping Configuration
Is crossover hot water recirculation a good choice for branch-type piping configuration?
I am considering replacing my aging hot water heater with a tankless. Several products offer a recirculation ...
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Tankless water heater supply configuration
I installed this Stiebel-Electron tankless. It was my first time sweating pipe, I enjoyed the process but I'm unhappy with the pipe alignment, the pipes angle with the heater is not truly plumb.
I ...
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tankless water heater low noise off and on all night
I just moved into a house with a new tankless water heater. It works fine when operating, but it seems to make a low humming noise off and on all night, when no one is using water. It is external, and ...
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Can I replace a 30 amp double pole breaker w/ 60 double pole breaker for tankless? Breaker is tripping
I replaced 28 gallon water heater: E1F30LD035V, with a tankless: https://a.co/d/1HokO6G.
The tank was hooked up to 30 double pole breaker.. I thought that was good enough for the tankless, but it ...
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What is the impact of outside scaling on the heat exchanger of a tankless water heater?
live in the mountains. hard water.
i descale 1-2 times a year.
still, there is visual evidence of scaling on the outside of the heat exchange. proximate to the bottom gasket and the glass-window.
...
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Can I split the cold water to get hot water (using a tankless heater) for a shower?
I have a small "casita" (a bedroom-size building separate from my house) where we want to add a bathroom (shower + sink). Since there isn't water in that structure we're planning on piping ...
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Can I replace a fried 60A tankless water heater wired to a double pole 60A breaker on 6AWG with a 40A tankless water heater?
Original tankless is a Eemax 13 Kw 60 A and the replacement is a EcoSmart 8 Kw requiring a 40A DP. Currently in our electrical box is a 60A DP. Do I need to swap this for a 40A DP or will the 60 A DP ...
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Which Residential Electric Load multiplier is valid for water heaters and EV charging?
I know how to perform a residential load calculation using either:
-(a) the Standard Method, which includes a 0.75 multiplier for fixed appliances (so, a 4500W water heater would be treated as adding ...
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Possible causes for a gas tankless water heater sometimes shutting down
I have a Rheem ECOH2OODVLN gas tankless water heater. I'm not sure of it's exact age as it came with the house, but it's in good condition (clean, no dust, no visible damage, etc.).
The situation: ...
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3x 100 gallon propane tank on 3 family building
I'm a new owner of a 3 family apartment building with 3 100 gallon propane tanks for heating and hot water for each unit. All 3 units have Navien tankless hot water heaters. I'm thinking about getting ...
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Tankless with a tanked hot water heater
I have a RV that I live in full time and I added a tankless in line with the factory tanked hot water heater (for trips or future plans I am leaving the tanked). I am having an issue of I can use up ...
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Hot water works only 10% of the time in kitchen faucet, works fine in other sinks
My kitchen sink hot water works inconsistently and mainly doles out cold water. However, if I turn the hot water in the bathroom sink the hot water starts working in the kitchen sink so I’ve just been ...
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What kind of putty should be used for sealing rim joist exhaust vent holes?
I recently had a tankless water heater installed in my basement. The 4" exhaust vents through the rim joist. I'd like to seal the gap around the PVC, but I'm uncertain what type of putty to use. ...
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Home Heating - Oil Boiler vs Propane Tankless
My house has redundant systems for both domestic hot water and hydronic heating (baseboard and radiant floor). I can pick and choose which system I'm running. We also have several mini-split heat ...
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What is causing my brand new tankless water heaterto knock?
I just had a Navien tankless water heater installed. It works fairly quietly when in use, but there is a knocking sound from the unit or the copper pipes hours AFTER it has been used (typically in the ...
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Retrofit tankless installation in an apartment building with rooftop solar
This is hypothetical, but based on a real case.
A landlord has an apartment building with 20 units. There is a single 150-gal gas water heater in the building that serves all the units. The landlord ...
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How should I secure T&P relief valve discharge copper pipe to the wall?
The copper pipe is the T&P relief valve discharge pipe and the white pex is for condensate.
What's the correct way to secure this pipe to the wall?
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Do tankless water heaters have a maximum temperature limit for the incoming "cold" supply water?
I currently have a tankless, natural gas hot water heater on the side of my house. I want to preheat the incoming water using a solar water heater. Is there any concern with having the input supply ...
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Where should I install a Kolerflo 120W water pressure booster pump?
I have a tankless water heater and the water pressure is not enough to turn the tank on demand causing the water in the shower to be just barely warm. I purchase a Kolerflo 120W to boost the pressure, ...
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Okay to use cold water drain valve on tankless gas water heater as a spigot?
I need to use a pressure washer outside my house, but there's no spigot nearby. I do have my tankless gas water heater nearby though, which has drain valves (both hot and cold). When I opened up the ...
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Do I need to flush my tankless water heater annually?
I bought a Rheem tankless water-heater last year, it is RTG-95XLN-1 model. I was told that I need to flush it using vinegar and circular pump at least once a year, to prevent sedimentation. There are ...
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Heating water L-shaped house [closed]
I installed a tankless gas hwh but it takes forever to get hot water in two of the three bathrooms. I am wasting water. Any suggestions on how to fix this?
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Do I need a 200 amp sub panel for my tankless water heater?
We are installing a tankless water heater that requires *3 50 amp 2 pole breakers. We are running new wire from the main breaker to a sub panel that will have those breakers in it and from there to ...
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Water heater tripping washing machine breaker
I just underwent a major renovation and now when my water heater is maxed out, it trips the washing machine breaker on its own dedicated circuit. I upgraded to 400A service with one of the 200A panels ...
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Outdoor direct vent tankless water heater (low nox) on exterior wall under overhang?
I have an exterior tankless heater that is one of the high-efficiency/low nox type, it has a direct vent (pretty small, actually) just sitting on the top grill.
This is mounted outdoors, but is it ...
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Adjusting water heater that provides both domestic hot water and baseboard heat
I live in an apartment building with in-unit water heaters. Mine is a Weil-McClain Gold CGt gas-fired water boiler with tankless heater. It heats water for domestic use and also for my baseboard ...
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Noritz Tankless Water Heater Error Code 90
My noritz tankless sometimes shuts itself off with error code 90 - a combustion problem. I’ve had a plumber come out and service it since the previous owners didn’t for ten years. I still get the ...
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Rheem T-Rex 13 tankless water heater 6awg 3 wire 60amp
Can I run my Rheem T-Rex tankless water heater on same 60amp breaker as my 240v dryer? Can I put in a junction box at my dryer area and run power to the tankless water heater?
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How to connect 113A tankless water heater 125 feet from main panel?
Looking into ways to connect a tankless water heater that requires 3 40A double pole breakers and has 113A max draw 125 feet away from my 200Amp main service panel.
Running 3 separate 8 AWG wires (...
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Shower gradually cools, gets hotter when sink is on. Navien tankless whole house HWH
Our shower and a few other fixtures are behaving strangely. When I get into the shower it gets hot quickly and then gradually cools. But, I found that if someone else turns on a nearby sink (but not a ...
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Should I turn off a Tankless gas water heater during freezing weather if I cut water to the house during vacation
I will be away from home during freezing temperatures. I plan to cut the main water supply. But, I have a Rheem tankless gas water heater on my outdoor wall. If I cut the water supply, should I also ...
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Can/should I change GFI outlet to standard outlet
I am having my retirement house built. The house includes two RHEEM RTG-84DVLN-1 tankless water heaters that are plumbed in parallel. The instructions
state do not hook up tankless to a GFI outlet ...
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How can I dampen a tankless water heater’s humming sound?
I just moved into our new home. First time with a tankless heater. I notice that whenever we turn on hot water after turning it off the tankless heater makes a humming sound. It seems like this is ...
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How to connect flex NMC to Rinnai tankless
I have a Rinnai V53DEP propane external tankless water heater. The manual calls for a disconnect, so I provided one.
My plan is (was?) to have a flexible whip take all the wires (power and remote ...
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Water Heater (Tankless), Furnace, Chimney? What order of work? Different contractors?
PRIORITY 1: I have a 21 (yes 21) year old water heater (go AO Smith!) that I want to replace with a tankless water heater (live in MD).
WANT 1: I have a chimney that needs to be lined and a fireplace ...
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How to wire a double pole breaker with #6/2 AWG wire?
I'm installing a whole house tankless water heater and I'm a little lost as to wiring this power hungry unit and yes I'm upgrading to 200a service(by electrician). I've done some wiring before but not ...
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Tankless hot water smells
We bought a house with a Rinnai RUC98 tankless hot water heater already installed. We didn't notice anything about the water at first except only that when we did laundry, the dried clothes smelled ...
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