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Tankless Water Heater

Hello Everyone, I am in the process of taking my electric water heater out and replacing it with a Rinnai heater. The gas company has already ran the gas line from the street to the house and it is going to be a 2lb system. I have ran 3/4 black pipe off of the heater with a union and cut off and dip leg in the line before going through the brick wall with a sleeve. I put a tee in the 3/4 line to run a small fireplace line off of later. I called the gas company to see how much they would charge to run the fireplace line and they sent a guy out here. He looked at my work and said it looked real good but he would have to take all the black pipe out and start over again and I ask why and he said I could not run the 199,000 btu tankless heater and the fireplace off of the 3/4 black pipe I put in. I have not done this in 15 years and I don't understand why my piping is not right. The fireplace is 40ft away from my and the line has to be run in the atic, I am on a slab. The price to do this was 1,050.00, I told them to get the [email protected]# out of my yard that is how mad I got. I am trying to save money by going with gas but it will take 50 years to start saving any money. I am going to try and send a photo of what I have done so maybe someone can lead me in the right direction. Thanks everyboby!!!
I love to fix things myself, just to see if I can.


  • heatpro02920
    heatpro02920 Member Posts: 991
    edited February 2013
    How long of a run?

    Around here its against code to run anything smaller than 1" inside a building {with a coupling NOT bushing}, you can down size to 3/4 when you get inside but from the outside in has to be at least 1". Also for natural gas Rinnai units, I run 1" gas lines, it will run with 3/4" but 1" is "more better".... You already have the 3/4" done, is the gas on and the unit working? I wouldn't pull anything else off of that line though {I know gas logs don't use much, but when that Tankless pulls in with a high she is going to suck some pressure up and fast}.. I had a service call, where I installed a Rinnai unit {older R53 unit years ago} and the customer years later had a restored gas on gas stove tee'd into my 1" line, when the rinnai unit started it would put the stoves pilots out instantly... I just ran the stove its own line next to the Rinnai's and problem was solved.... I also converted his restored stove to electronic ignition and wall hung thermostat a while after that {I know unrelated :) }...

    2lb system, Where is your regulator?

    And I dont use gate valves for rinnai units, full port ball valves are the way to go....
  • barmesome1955
    barmesome1955 Member Posts: 8
    2LB system for Tankless Water Heater And Fireplace

    I live in Winston Salem NC and I thought the gas company would put the regulator by the meter when they set it. (this Is My House I am Working On) I have not got this system inspected yet ,just got a permit to do it. I wanted to make sure I am putting in the right size pipe and to make sure I did not need to change anything before I called for final inspection. The meter is right outside the wall where the 3/4 line is running out. It is right behind the W/H on the outside wall. Should I go ahead and take this piping out and start over and put a regulator in myself under the union at the bottom of the W/H? Will 3/4 not run my W/H and Gas log on a 2lb system. I am thinking of not even hoking up my gas logs because it is so close to spring time. Thanks for the replie's
    I love to fix things myself, just to see if I can.
  • heatpro02920
    heatpro02920 Member Posts: 991
    I don't know your codes.

    But if I was installing that unit here, I would run 1 1/4" in {sleeved if going through anything but wood} from the meter into the house. I would have the regulator outside on the meter {supplied by the gas co.], then I would install a 1 1/4 x 1/2 x 1" tee, plug the 1/2", run the 1" up the wall to the unit with a gas valve {not regular ball valve, some Ball valves will pass, but dont take the paper spec sheet off of it, and i find gas shut offs get turned off by accident much less, people tend not to touch them plus no big handle to trip}. have the union rite on the unit going to a 2" 3/4 nipple going to a 3/4 x 1 tee, install your drip leg on the bottom of the tee connect the 1" to your gas valve... Inspector wouldn't have anything to say....

    I do a lot of installations, and I have dealt with inspectors in 3 states, from countless town, I have heard it all, No spec sheet for ball valve used on gas line {even though it is cast WOG}, gas valve not in plain sight {gas valve should be as close to eye line as possible}, elbows betweent drip leg and unit supply, ect, ect, ect..... Now of course theese are examples, of course not from my work since I do everything rite, and posses mind reading powers that lets me know how the code book is going to be interpreted by an inspector that never held a pipe wrench in his life ;) .....

    Anyhow, it all depends on who inspects it and if he had his coffee yet and if he doesnt have a grudge against DIY'ers {I have seen that also}.... But I am in the crooked east, I remember years ago some guys used to just pay for their {pre and post} inspections and then do the job how ever they seen fit....

    If you are that close to your unit, you dont need to run 2psi of gas into your house, I wouldnt, I dont like regulators indoors, I would regulate down before you enter, come in big, you will only need $20 of 1 1/4" pipe and fittings {not sure if you are buying nipples or cutting yourself?}.... Have them bring the regulator or go pick it up, that will make life easier too..

    Also don't get on the bad side of the gas co techs, them guys are your friends.... Don't make them enemies because you will be sorry in the end, and they still get paid at the end of the day whether they hang your meter or not...

    PS- Some places around her we need a sprinkler over that unit too, as well as a same circuit hard wired smoke and that circuit has to be designated with a fireomatic break before feeding anything... But I have put in plenty with out any of that stuff and they all pass, but there is one town that the inspector wants it all, and I know to price accordingly there and install it all, not to cause problems, not worth arguing when they hold the CO release....
  • CMadatMe
    CMadatMe Member Posts: 3,066
    edited February 2013
    Gas Pipe Sizing

    3/4" 40' = 130,000 Btu/hr

    1" 40' = 245,000 Btu/hr

    1-1/4" 40' = 500,000 Btu/hr

    How many btu/hr is the fireplace? How far is the tankless from the gas coming into the house?
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • RobG
    RobG Member Posts: 1,850
    Gas line

    If your current gas piping is sized correctly for the tankless water heater, I would tee off outside before the pounds to inches regulator and run 2psi to the gas logs with another regulator at the gas logs. That way you can keep the gas log piping as small as possible.

  • barmesome1955
    barmesome1955 Member Posts: 8
    2LB system for Tankless Water Heater And Fireplace

    Thank's for the replies everyone, I am going to hire someone that know's what they are doing! I don't want to have a big big boom!!!
    I love to fix things myself, just to see if I can.
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