We’ve been thinking about installing a tankless water heater for quite a while, but got a lot more serious about it over the last few months.  We started by insulating and building a stud wall in the furnace room where the new water heater would hang.  Then, a couple of weeks back, we finally bit the bullet and accepted the bid from a local plumber for his work to install a Rinnai RU98i tankless water heater in our furnace room and simplify/remove a bunch of old plumbing that would no longer be needed once the old water heater was gone from the workshop area.

Once we accepted the bid, things moved pretty quickly, with work starting last Wednesday on the rough-in for the new water heater.  The plumber and his helper started by installing a new gas line from the meter to the furnace room, which would serve both the furnace and the new water heater.  This replaced an old, low hanging gas pipe that ran through the hallway, into the workshop (where the old boiler and water heater were) and then looped back around into the furnace room, basically taking the long way around the entire basement.  The new gas pipe is tucked up to the ceiling and takes a much more direct route to the appliances that use it.

Since I know before and after pictures of plumbing are in such high demand, here’s a photo of the old gas pipe before any work was done.  It’s the lower, kinda rusty looking one that’s cutting through the block wall before circling it’s way around the entire basement.


And, here’s the after photo.  The new gas line is the black pipe that’s tucked up into the rafter bay and hangs a left before it gets to the block wall.


The plumbers also spent some time on Wednesday installing the concentric vent pipe from the new water heater to outside.  Normal installation would be to vent the water heater directly out the wall where it is mounted, but, in our case, the back steps are directly outside that wall, so we couldn’t do that.  Instead, the vent pipe runs in a joist bay along the ceiling all the way to the side of the house and exits there.


This is a pretty long path to the outside and isn’t what we were originally thinking, but turned out to be the best in the end since there are so many requirements about where the vent can be located.  It needed to be a certain distance away from operable windows and air conditioning units and also needed to be at least 18″ from ground level (to avoid being buried in snow in the winter), so this location was really the best/only one for it.  Since this is the side of the house that faces the deck, I was a little concerned that the vent would be pretty ugly to look at on the side of the house, but, because this unit uses a concentric vent pipe, it’s really not as obnoxious as I’d imagined and will be even less noticeable once the plants leaf out some.


On the second work day, the new water heater was plumbed and fired up.  Most of the work that was done on day 2 was making up the connections to the water heater (hot and cold water, gas, condensate, overflow, and vent) and then doing enough plumbing on the hot and cold water lines to take the old water heater out of the loop.

Rinnai RU98i Tankless Water Heater - Installed

Then, last Friday, the plumber came back to finish up.  This was when we really noticed the “pay-off” on all of the related plumbing work.  He removed all of the old water and gas pipe from the ceiling of the workshop and hauled out the old water heater.  He also re-connected a new, small gas line to the fireplace and re-plumbed an outdoor faucet with copper pipe.  By the time he left on Friday, the basement looked quite a bit different than it had when he started, especially in the workshop.  It’s amazing because the water heater really wasn’t all that big, but having it (and the mess of plumbing on the ceiling) gone makes the room feel so much more usable.

Here are some before photos:



And here’s the same room now, with all of the plumbing cleaned up:



As far as the new water heater goes, so far we are impressed.  We have ran the dishwasher and washing machine and taken 2 showers at the same time with no noticeable impact to the hot water temperature.  Not running out of hot water is a pretty cool thing, too – especially when we were used to running out after about 12 minutes of running two showers at the same time every morning.  And as an added bonus, which we hadn’t really thought about beforehand, our hot water pressure is noticeably better (maybe because of the old galvanized pipe that was replaced with copper or maybe because of the switch to a tankless water heater – we’re not sure, but we’re definitely not complaining).

All in all, we’re super happy with the way this project has turned out.  Removing/updating all that plumbing in the basement has been on our to-do list for forever and it feels so great to have made some progress in the right direction.  The switch to a tankless water heater has been great so far, too.  Seriously – nothing beats a hot shower every single time.  What a luxury!

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4 thoughts on “Installing a Tankless Water Heater (and Related Plumbing Work)

  1. Jan says:

    We love our tankless. We noticed a big decrease in our gas usage. Anyone who is away from home from morning to evening should see a savings because their water heater would never come on unlike the old style that just keeps reheating the same water all day long.

    1. Sarah says:

      It’s too early for us to tell, but we’re hoping to see that decrease in our gas usage as well – like you said, it makes sense that we would … although probably not enough to ever pay for the installation of the new water heater. In our case, the decrease should hopefully be even more since we discovered during the course of this project that our humidifier had been plumbed into the hot water line rather than cold, so we suspect our water heater was probably running every time the furnace & humidifier ran, too … and we wondered why our showers always seemed warmer following a cold night when the furnace ran more. Ha!

  2. Gillian says:

    Switching to tankless was one of the first “major” renovation items we did. SO expensive but it is wonderful having hot water on demand and not having to worry that the person showering after you won’t have enough hot water :)

    1. Sarah says:

      I agree – I keep catching myself thinking about running out of hot water before I remember that won’t happen anymore. It’s weird (and wonderful) to not have to think about that anymore! So glad to hear you still love yours! :)

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