Tankless Water Heater Installation

So...the 17 year old water heater in the garage finally kicked the bucket.  We knew its days were numbered when we bought the house over 2 years ago.  A couple of weeks ago, it started with a slow leak.  Then the Pressure Release Value started leaking too.  So I knew I wanted to go tankless.

I got quotes from $2300 to $3700.  Some would discuss optional models, some only had a certain model they worked with.  In all cases though, it was going to be at least 3 or more days before I could get hot water back in the house.  So I ordered up a recommended unit from Amazon Prime.

Initially I went with an exterior unit due to the ease of the venting and the location was also not bad.  But after further analysis, I decided on an interior unit.  The interior unit just dropped right in.  I went with the Rinnai RL94iN Natural Gas Tankless Water Heater, 9.4 Gallons Per Minute.

http://www.amazon.com/dp/B0058DQLPW/ref=pe_175190_21431760_M3T1_ST1_dp_1

For venting I went with the

http://www.amazon.com/dp/B0058DQLPW/ref=pe_175190_21431760_M3T1_ST1_dp_1

Luckily I already had a 2 PSI system.  However, the regulator for the original electric hot water heater was in the crawlspace and the distance from the regulator to the tankless was too long to deliver the proper BTUs.  Also the system had a few splitters and the tankless would be by far the most demanding.  I have two gas furnaces, a gas 6 burner cooktop, gas logs in fireplace, and gas grill on the deck.  There were too many splitters where the original hot water header was connected so I added another splitter right where the gas line entered the foundation.  I then ran a dedicated flex tubing run to the original piping.  Of course I also removed the regulator in the crawlspace and moved it to within a few feet of the tankless hot water heater.  I did spend a lot of time with the piping getting all the sediment traps right along and other valves.  Overall the project was not too bad once I got a plan in place.

Plumbing was straight forward.  I used two Sharkbites for one 90 degree turn.  For the small bit of piping I needed, I used PEX and it was much easier than I expected.

As for the electrical, you need to make sure the Rinnai plugs into a GFCI plug.  I replaced an outlet near the unit with a GFCI with no problems.  To bring my home up to code, I did need to install a 6 gauge earthing cable from my gas meter to the electrical panel's ground on the outside of the house.  That was also pretty straight forward.

Of course the unit itself could not be mounted directly to the studs since the screws did not align with any studs.  I ended up mounting a small sheet of plywood cut to the proper size.  That took some planning since the vent would also need to have a hole cut before anything was mounted.  I just took my time and made sure all the cuts were exactly what I wanted before making them.

During the inspection, I did end up having to install a shutoff valve right where the supply line entered the foundation.  Without cutting off the supply to the meter, the regulator on the meter would leak when I pressurized the system.  It took a bit to determine that cause.  Once the shutoff valve was in place, the system pressurized just fine and held.  To be on the safe side, I also put a carbon monoxide detector right next to the unit.

It has been in for almost a year and has been running flawlessly.  I will so be doing the standard annual maintenance.

Let me know if you have any questions,
smanders