Tankless Water Heater

**1slowbusa** · 08-28-2011, 09:49 AM

Ok so my tank for my water heater is leaking on the bottom were the heat exchanger is inserted. I ordered a gasket but i hope its not rusted. But if it is i have been looking at the tankless water heaters.

Who has installed one and are you happy with it? Do you recommend or not?

Also there is a $500 tax rebate if it is installed before December 31, 2011. Is it worth it?
Thanks

**pajeff02** · 08-28-2011, 10:35 AM

I installed a Rinnai when we built the addition on the house. My only complaint is that it does take a while for the water to come up to temp. This is exacerbated with longer runs from the heater to the faucet. The old style hot water tank sends hot water into the line immediately. Although it still took time to get to the faucet, the old style was much faster than the Rinnai. I generally turn on the hot water to brush my teeth and then run it a bit more before I can shave and shower in the morning.

**Zapper2003** · 08-28-2011, 11:40 AM

More on the 'taking forever' to get water issue. As said, the run from the heater to the faucet needs to be factored in, however, with a standard water heater you have 30/40/50 gallons of 120*+ water sitting there with nowhere to go, and as we all know, heat rises. The hot water is always rising into the pipe and into your water system, pre-heating the water in the lines. With a Rinnai or any other tankless water heater, when you close a faucet, the flow stops, therefore the heater quits heating, and you have zero thermal rise from the tank to your lines. Before, you noticed hot water quicker as the column of water in the line was already pre-heated by the water in the tank, but now you've got no pre-heat effect so it seemingly takes longer to get hot water to your faucet, and when it does get there, it's exactly the temperature you wanted, it doesn't slowly get warmer as with a standard heater. It's not a huge deal, but people notice this first above any other issues as it is a fairly drastic change in the way things used to be.

**ls1camino** · 08-28-2011, 03:00 PM

I replaced he heating elements on my water heater a few months ago, and it wasn't hard. Most of the time from start to finish was waiting for the tank to drain. The actual switching of the elements was less than 5 minutes.

**1slowbusa** · 08-28-2011, 03:45 PM

Yea there is nothing wrong with the heating element, its just leaking around 1 bolt that holds the heating element in. I have a new gasket but i have to get home to get the tank out and take a look. Hopefully its not rusted around the bolt.

**IHSS** · 08-28-2011, 07:10 PM

I just got rid of a tankless system. My house has forced hot water and the boiler did the heat and the hot water. My issue was that the boiler would cycle all summer long to maintain the water temp and every time the hot water was turned on the boiler would fire. It was nice haveing endless hot water but the price of oil made me cringe every time it fired up. My town has its own electric company and electricity is real cheap, so I saved a good chunk of money by switching. So you should look into some other factors before deciding. If oil was still cheap I would've left it. They also have point of use water heaters that mount under a sink or shower you need more than one but they have instant hot water when ever the hot water is turned on.

**pajeff02** · 08-29-2011, 03:15 AM

Originally Posted by IHSS

I just got rid of a tankless system. My house has forced hot water and the boiler did the heat and the hot water. My issue was that the boiler would cycle all summer long to maintain the water temp and every time the hot water was turned on the boiler would fire. It was nice haveing endless hot water but the price of oil made me cringe every time it fired up. My town has its own electric company and electricity is real cheap, so I saved a good chunk of money by switching. So you should look into some other factors before deciding. If oil was still cheap I would've left it. They also have point of use water heaters that mount under a sink or shower you need more than one but they have instant hot water when ever the hot water is turned on.

Our other house has a similar unit that heats both the home and domestic hot water with oil. We really have not noticed it running a whole lot in the summer. I turn the power off when we are not there and upon arrival it will run for maybe 2-3 minutes when I turn the breaker back on. After that it may kick on a couple of times during the day and run for real short periods without water being drawn. Turn on the hot water and then it always kicks on after 30 seconds or so.

**Zapper2003** · 08-29-2011, 06:37 PM

Originally Posted by IHSS

I just got rid of a tankless system. My house has forced hot water and the boiler did the heat and the hot water. My issue was that the boiler would cycle all summer long to maintain the water temp and every time the hot water was turned on the boiler would fire. It was nice haveing endless hot water but the price of oil made me cringe every time it fired up. My town has its own electric company and electricity is real cheap, so I saved a good chunk of money by switching. So you should look into some other factors before deciding. If oil was still cheap I would've left it. They also have point of use water heaters that mount under a sink or shower you need more than one but they have instant hot water when ever the hot water is turned on.

Originally Posted by pajeff02

Our other house has a similar unit that heats both the home and domestic hot water with oil. We really have not noticed it running a whole lot in the summer. I turn the power off when we are not there and upon arrival it will run for maybe 2-3 minutes when I turn the breaker back on. After that it may kick on a couple of times during the day and run for real short periods without water being drawn. Turn on the hot water and then it always kicks on after 30 seconds or so.

What you guys are referring to is a domestic coil, not a tankless water heater. It used to be that most, and now just a few, oil boilers were available with an installed copper coil heat exchanger inside of the boiler itself. The boiler water surrounded a coil filled with the domestic (hot) water that you use. The boiler would maintain 180* all year round to satisfy the demands of that domestic coil. The cold, city or well water traveling through the coil would cool the boiler temperatures to 140-160* and then the boiler would come on to reheat up to 180* to keep the water at your faucet hot enough for use. As mentioned the problem with these systems was short draw-down time, constant short-cycling of the boiler and burner, and the price of oil. In the winter time they were great as you were getting what they referred to as 'free' hot water (technically just parasiticly-heated hot water lol), with the drawback of running all summer long. An option for these systems to to change out the aquastat to one that does not maintain, and add another zone in the form of an indirect fired hot water tank, which still uses the boiler, but has a storage capacity of 30+ gallons, so instead of cycling every 3 minutes, it will cycle every few hours. Or go tankless.

**pajeff02** · 08-30-2011, 08:29 AM

How about you just join us at the track some day and take a look at what we have down there? I don't know if it is just looping through the boiler or if it has a separate reservoir. I think it cycles on and off when hot water is being drawn rather than run continuously.

**Zapper2003** · 08-30-2011, 06:18 PM

I'll try to make it down some year. *le-sigh*

**1slowbusa** · 08-31-2011, 04:06 AM

What track do you guys go to?

**Spikito** · 08-31-2011, 05:44 AM

from what ive heard, theyre great if your heater is close to your shower, some people have more than one of them, depending on house size,

If building new, people tend to run smaller piping to deal with that issue....which to me, means that in a home already built, heating time is def an issue

**pajeff02** · 08-31-2011, 03:29 PM

Originally Posted by 1slowbusa

What track do you guys go to?

Beaver Springs Dragway. Next planned outing is September 11th and looks like we should have a couple of cars there.

**Zapper2003** · 08-31-2011, 06:18 PM

Tankless heaters, at least our rinnai's, heat the water to your setpoint instantly. No warming up, none of that business. It's the hot-water line going cold in between uses that people cant seem to get used to. All you have to do is run the hot water spigot a little longer to get the hot water there, but once its there, its endless and will not run out, ever, until you close the spigot, then it will shut off completely. If you set the Rinnai to 125 degrees, as soon as it starts heating the water, they 'guarantee' the water at the outlet of the unit to be 125 degrees. Granted, that doesn't account for line-loss and the cold piping absorbing some of that heat.

**pajeff02** · 08-31-2011, 06:21 PM

We run our Rinnai at 110 degrees and that seems to work well.

**Zapper2003** · 08-31-2011, 06:33 PM

The lower the temps, the less gas you use. Could be part of why it seems to take 'longer' for it to come to temperature. We generally tell folks to start at 120 or 125 and go from there. We've got one out there and they run it at 180, but its also in a milking parlor and the hotter the water, the cleaner the pipeline.

**pajeff02** · 08-31-2011, 06:35 PM

Did not know that - I think the burner is multi-stage, so maybe calling for a hotter temp maxes it out?

**Zapper2003** · 08-31-2011, 06:41 PM

The Rinnai is modulating, yes. It will burn anywhere in the range of ~10k-180k btu's based on flow through the unit. Technically yes, it could still burn 180k @ 110*, however, your temperature rise would have to be pretty rediculous and your flow rate at or about maxed out.

**1slowbusa** · 08-31-2011, 07:24 PM

I wish it wasnt so far (130 miles) or I would be there.

**pajeff02** · 09-01-2011, 03:50 AM

Originally Posted by 1slowbusa

I wish it wasnt so far (130 miles) or I would be there.

We're 100 miles away, Cpop has to be about the same, and TLS is probably 135 miles out from BSD. However, we have a house less than 2 miles from the track and will be there for the weekend. Gives us a place to hang out and chill before and after the track.