Tankless hot water heater installation

I wrapped up the installation of a tankless (“on-demand”) electric hot water system for the house over the weekend. It was rather demanding of skills and time. Over a month ago i had received the first heater using a buy-it-now link on eBay. The Titan SCR4 (their beefiest model) was new so the only savings to me was the shipping was free. I spent the better part of a day removing the old electric hot water heater (which needed to be replaced) and plumbing in the connections for the unit. I also did the wiring and tried to be cheap about it and didn’t buy any additional wire (the unit comes with about 18 inches of wire for each connection) so mounted the heater very close to the electrical panel. The heater requires two double pole 40 amp breakers so a single heater will take up 4 slots of a breaker panel. Unfortunately the instructions that i followed online indicated that the heater needed only one double pole sixty amp breaker. We let water flow through for a while and then kicked on the breaker. The water only warmed a little. Despite the manufacturer’s claims that the unit was designed for “colder climates” and “large homes” we found the temperature increase inadequate for even washing dishes. We do live in Alaska and it was winter. I found instructions on installing two heaters and bought another one. I am certain that if we had used two 40 amp breakers that the heat output would have been greater.

Titan tank-less dual heater setup

The illustration above shows my installation. I used ample valves because i wanted the ability to remove either unit for service or warranty repair and still be able to use the remaining heater. There was quite a few hours invested in cutting pipe, soldering, and wiring. The water temperature is very nice now and i have actually turned the temperature dials on both heaters to about the middle of the range of settings. Hot water seems to arrive at the faucets and shower head faster than on the hot water tank system. The only drawback we have is that all the lights in the house have a slight flicker to them when hot water is being used. Unfortunately that includes when the toilet is flushed (which is going to have to be a future plumbing project – we don’t need warm toilet water). Seisco claims to have a system that does not cause lights to flicker.

Material list and prices:
2 Titan SCR4 heaters @ $450 each =$900
4 40 amp double pole breakers @ $21 each (only $10 each at Lowe’s) = $84
9 feet of 8/2 wire and wire nuts = $20
6 1/2 inch gate valves with compression fittings @ $10 each = $60
Copper pipe and fittings ~ $80
Over $1,140 total

A standard electric hot water heater with a tank would have cost about half that. With a life expectancy of up to 20 years (according to energystar.gov) the tankless electric heaters should last almost twice as long as the tank system. Carrying the assumption that this system will last twice as long as a tank system means that any savings in electric cost will be money in our pocket. If 15% of our electricity bill is spent on heating water and we see a 45% improvement in efficiency (see this Energy Star document) and our electric bill is $120 a month then we should see a savings of about $8 per month with this setup. If the system lasts 20 years the total savings would exceed $1,920 making the entire system more than pay for itself in our case. On top of all that it looks like the on-demand system system will qualify for a substantial tax credit for energy efficiency.

[Edit: Our additional electrical load actually caused the failure of a transformer out on the power pole outside of our house. It is advisable to contact your power company before adding service like this. They replaced the transformer and the lights didn’t flicker as much when we used water. Then they increased the size of the line feeding the house from that transformer and now the lights just dim a little when you first turn the water on. We’re happy with the setup for the most part now!]

zieak (2207 Posts)

Ryan "Zieak" McFarland dabbles. Beards. Making things. Travel. Genealogy. Frugality and excessiveness. Fitness and fatness. He's a PE teacher in India, usually calls Alaska home and is a happy father to two boys and the husband to a suddenly crafty wife.

28 thoughts on “Tankless hot water heater installation”



  2. Rey,

    I’m not an electrician but i think you did install it correctly. Mine came with three wires – one black, one white, and one bare. The bare was wired to the circuit panel ground and the white and black to each of the connections on the double pole breaker. You might try calling the manufacturer. Sorry.

  3. Thanks for the story zieak. I live in Miami and have the same problem with the flickering lights. I spent a lot of time with the electrician trying to fix the problem which is compounded by Florida Power and Light’s (FPL) refusal to diagnose the problem as originating from them.

  4. It would appear you would have a good supply of hot water using two SCR-2 together, rather than using one SCR-4. Anyone used this configuration??

  5. I am confused why do you need an extra water heater for your installation. The temperature rise are based on the flow rate (in unit of GPM – gallon per minute) of your water flow. Would it be the water heater capacity wasn’t fit for your local water flow rate?

    There are quite a few guides on the Internet in calculating the size (capacity) of the tankless water heater vs location – simply googling it should get you to the right spot.

  6. Ok – i’ll bite on this spam – I live in Alaska so the groundwater temperature is fairly low. I also have an apartment so despite having low flow shower heads the ability to make plenty of hot water is pretty necessary.

  7. I just bought a SCR2 on Ebay & installed it. I’m having a problem with the lights flickering.
    The person i bought it from said that can be caused from a bad Ground.I’ve soldered the ground at the point where i wired the unit up & still get the flickering lights.The ground in the breaker box seems to be tight.I may try & make a separate single ground for the SCR2 using a pure copper rod & see what happens.
    He also said the flickering could be caused from the breaker being at the bottom of the breaker box.My dual 60 amp breaker is in the second from the top position.The breaker is brand new !
    I have it set to max heat & can’t seem to get a full shower with consistant temperature.
    Its refered to as sandwich effect on some other websites.
    P.S. For those of you who don’t want to solder the copper connections, their is copper glue you can buy.Its easy to use.Works great.

  8. From an email i received…
    Hi Zieak,

    It appears the instructions you initially followed are meant for the Titan SCR2 N-120, as this is the model that requires the 60 amp double pole breaker.

    Since you did not supply the correct electric connections to the Titan SCR4 N-180, the water heater did not perform the best of its capacity. I’m sure that if you had wired it properly from the start, it would have performed quite well, even in Alaska weather. :-)

    By the way, there is an even more powerful model available, the Titan SCR4 N-210. Now, about your flickering lights. Each N-180 has a max amp draw of 77 amps. You have two of these units, for a potential max amp draw of 154 amps. Most panels have a maximum capacity of about 200 amps. So you may be pushing the limits of your panel’s capacity. This is the reason why your lights may be flickering. The demand may just be too high. I’m assuming you have a 200 amp panel, it may actually be smaller or a bit larger.

    Allow me to make a suggestion. Employ only one of the Water Heaters. According to your diagram, the installation looks very nice. You have the breakers and the valves in place, so disengaging one of you heaters is quite simple. Just shut the water valves supplying water to one of the heaters, as well as the breakers powering it. You want to try using only one heater. This should cut down on your electric bill, as well as reduce, or even eliminate the flickering of your lights. And one unit should also have sufficient power to provide a good shower.

    Best Regards,

  9. i got the titan n120 and have installed it. i have a 60 amp double pole breaker and 6 gauge wire installed.

    the problem that i have is that when i turn on the hot water, only warm or no difference water comes out of it. i have the temperature control on high but still it doesn’t work. and also when i turn the water on low in the faucets the water gets warm but when i turn the faucet on high then the water gets cold again. i have checked the wires and i cannot find what is wrong.
    can you please help

    thank you

  10. Guliy,

    I would try to get in touch with Martin at Titan. I sort of have a similar problem. Our two units work great for everything except for when trying to fill the bathtub. It just seems to pull too much water through the units and they seem to shut off. If we turn the water off, wait 15 minutes and then turn it on at a slower rate (not on full) then it is able to keep up. This is easy for us to deal with because we never use the bath. We do have to warn guests that use that bathroom to turn the shower on immediately which reduces the flow to around 2.5 gallons per minute. You might want to try to install a flow reducer on the faucets. Usually you can just get a threaded insert for faucets that will specify the GPM on the packaging. Good luck – please feel free to reply here with what you figure out.

  11. I have the same issue as guliy. I’ve followed the horrible directions given with the unit and still no hot water. I’ve double checked the connections adn everything is ok. the units red lights turn on when a faucet or tub is turned on and the pipe gets really hot coming out of the unit, but my problem lies in that we don’t get any hot water in any parts of the house. It barely gets luke warm. My wife is about to eat me alive if i dont’ get this fixed. what else can i try??

  12. The only thing that might work is reducing the flow of the fixtures. If you turn the water on hot but only a low flow does it warm more than luke warm?

  13. Had the flickering light problem for a year with two Titan 120s installed. The issue is low voltage, or over amperage on the feed lines.

    Bugged the electric company, and they moved the local transformer one pole away from my house and all is well.

    To trouble shoot, start with a voltage/amperage check at the lines coming into the house to determine if the problem is the feed coming to the house, or the house wiring.

    From there, make the changes necessary.

  14. The best ever water heater that I experience is the Marey Brand. The company is doing good in the service…They improve so much. I recomended to anyone…

    I have many years intalling this water heater specialies in the Santon Power Pack and Power Gas 20 lts Gas Tankless water heater.

    Good variety in the Tankless Water Heater…

  15. Omega 2000 Group Corp (Omega 2000 Group Corp)
    314 E Kimball Ave, Hemet, CA 92543-4240
    Google map the headquaters for the Marey water heaters

  16. I bought a Marey tankless LP water heatr. It came with instructions to attach the supplied barbed fitting and push on a soft LP gas hose. Also it said to disconnect it when not in use.
    When I tryed to connect a vent to the unit, to my surprise, I found that it took a 3.5 inch vent pipe. There is no such pipe sold here in the US.
    After many failed attempts to contact Marey, both email and phone, to no avail, Here I am. Before you buy an LP gas water heater from Marey, get all the specifications.

  17. I’ve purchased a Marey NG-FI whole house tankless water. It takes approximately 2 minutes for it to produce hot water. Even
    after running water for a few minutes, then turning it off and then back on, it still takes up to 2 minutes to get hot. Also I can’t regulate the temperature on front of the control panel. The temperature stays constant at 115 degrees. It will not turn off from the control panel either. I tried calling the manufacturer with no luck. Finally contacted them by e-mail. There suggestion was to return it. Now by the time I take the unit apart, send it to Puerto Rico, What in the world am I suppose to do for hot water until they send the unit back to. can’t return it to retailer either, time has expired. So if anyone has an answer to this problem I surely would appreciate it.

  18. I did the same thing as you but I used two of the smaller models as I am in Virginia. I bought two Titan N-120s from the company at http://www.TitanTankless.com and installed them in parallel. It works great for me and cost me a lot less. I dont have the light flickering issue as it is a newer home with upgraded electrical. My electric bill dropped about 25 or so per month consistently but a great tip now is that I can shut off one of them in the summer as I dont need to run both now so I am saving even more. Lots of pluses and I get endless hot water that is the hottest in the neighborhood here!! I have diagrams if anyone needs it.

  19. I just wanted to let the readers know that Titan Tankless has come out with a more powerful model than the N-210 listed here. The newest and most powerful 2011 digital model tankless water heater is now the N-270. This model needs two 50 AMP double pole breakers.
    This was made for larger homes and homes in colder norther climates. I had the N-180 and upgraded to this model as I added another bath. It did the trick and I just had to swap out the breakers. The dimming of lights is just an imbalance in your breaker box and after adjustments and balancing it should eliminate that issue.
    You can see the N-270 at the company website:

  20. March 22, 2011

    I need your help. I had an elecrician install a Titan Model N-120. Right after installation as I turned the faucet ON the water immidiately began to warm up perfectly but I noticed the lights began to flicker some what….that same afternoon….turned the hot water ON…no hot water. Also noticed I had no power at all in the rest of the house. Checked the main breaker outside and it had tripped. Re-set breaker and all worked well including water heater plus reduced temperature control from HI to MED. Investigated a bit more and noticed water heater was installed on a double pole 50 amp breaker instead of a double pole 60 amp breaker as manufacture recommends.
    Could this cause the main breaker to trip?

    Miami, Florida

  21. re: MAREY ECO180 TANKLESS WATER HEATER. ANYONE LOOKING FOR A HOUSE FIRE?? Marey ECO 180 Tankless Water Heater Specifications for wire size, breaker, etc appear to be GROSSLY UNDERSIZED.

    This electric ‘whole house’ tanbkless heater appears to use two heater strips for each side of the 240 Volt line. Each heater strip is 9 ohms. Resistors in paralell divide so each side of the line, when enabled or turned on, sees only 4.5 ohms resistance for the incoming 240 volts AC.

    Ohms law says V/R=A where V=Volts, R=OhmsResistance, A=Amp(current) Thus 240/4.5=53.3 amps.

    Marey manual shows one double pole 40 amp breaker. Spec sheet in the same manual says minimum 50 amp breaker. How will a 53.3 amp current survive on a 40 amp breaker? The units sticker says a 50 amp breaker. How will a 50 amp breaker su4revie a current of 53.3 for any length of time. IT WON’T and DOESN”T. Mareys customer manual for this unit says maximum current draw is 75 amps while their website specs for this same ECO180 heater says maximum current draw is 125 Amps, (which is about right). Marey says to use a #8 wire but a current of 125 amps needs a #4 or better. Customer service says a 40 amp breaker is large enough. HUH !!!

    Repeated customer service contact was negative with no corrections or admissions of error coming from their end. What is wrong with these people?

    Keep your i\nsujrance up!! House fires anyone?

  22. We are looking to get a electric tankless water heater. We don’t know much about them. Could anyone give us some insite on them. We were looking at whole house models. we have 2 bathrooms, 3 sinks and a dishwasher that all require hot water. What would be the best and most efficient for us? Any help welcome.

  23. I bought a Titan SCR4 water heater on E Bay but it didn’t have the intructions in with it. It has 2 seperate electrical leads coming from it, with a black wire and a white wire plus a bare copper ground wire. My question is does each one of those leads use a 240 volt power source? If so does that mean that the balck and white wires have to go to my 2 douple 40 amp breakers?

  24. Need help on marey eco180 installed on August 2012 with 2 double pole 50amp breaker and it to Worked perfectly. On May 2013 it show error code E2 creeper. Called customer service all he said is elctric problem. Then i went to checke my eletric wiring and connection it’s right. I’m not electrician but i’m an electronic technician. Doest any one out there have the same problem and know solve?

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