[67 455 Bird ragtop]

Who's using a tankless water heater ??? I'd like to put a small one in my new garage. Can either be electric or LP. Natural gas not available in my area. Only need one to handle and occasional shower and sink.

["Me"]

Would probably be all right in a limited use role such as you describe. They tend to not last so long in my area [whole house]because of mineral buildup.

Larry

[Speargun]

A buddy put one in his new house about 3 years ago. The electric company had to come out and install a new transformer on the pole because with everything on, he was pulling around 350 amps. Once that was taken care of, the lights quit flickering when the hot water was being used.

My shower was within 15 feet of the instant on hot water heater and had a tendency to "pulse" hot water. I.e. hot, cool, hot, cool... It wasn't unbearable, but it was annoying.
His room was on the other end of the house, about 40' away, and didn't have the same problem. My guess is that the water temp had a chance to average out in the pipe and thus gave a steady temp.

For a "lake house", small shop, sink, or anywhere there is only an occasional use, I would say that they are a good option since it is only on when you need it.

If you have mineral in the water just pick up a whole house filter at Lowes or Home Depot to help catch most of it before it gets into you heater.

[tom s]

I have one in my pool house.Im told they are not too good for really cold weather as they only can raise the temp so much from the inlet water temp.Tom

[carcrazy]

In my experience, I have seen them work well in 7,000 square foot houses and poorly in 1500 square foot houses. Proper size and installation is critical in a whole house application. Inspected a house yesterday that had two Renai R85's with a pump. (natural gas) This should have been plenty big but performance was marginal. Measured max temperature with two fixtures running was 111 degrees. Temperature would sometimes drop significantly for no obvious reason when the water was running for a few minutes and then it would get hot again. Service techs had been to the house several times and still couldn't solve the problem.
I think a tankless would be fine for the minimal use you are proposing. (don't count on saving much money)

[67 455 Bird ragtop]

Originally Posted by carcrazy

In my experience, I have seen them work well in 7,000 square foot houses and poorly in 1500 square foot houses. Proper size and installation is critical in a whole house application. Inspected a house yesterday that had two Renai R85's with a pump. (natural gas) This should have been plenty big but performance was marginal. Measured max temperature with two fixtures running was 111 degrees. Temperature would sometimes drop significantly for no obvious reason when the water was running for a few minutes and then it would get hot again. Service techs had been to the house several times and still couldn't solve the problem.
I think a tankless would be fine for the minimal use you are proposing. (don't count on saving much money)

So you think a smaller standard electric might be better ??

[GTO1]

I have tried Bosch, Takagi's, Noritz and Rinnai's. I like the Rinnais the best. My company has installed over 100 this year. Try to go with the LP unit. I have installed the electric, thank God the homeowner provided it, we charged them to pulled it out in less than two months. The most important thing for a tankless water heater is having the gas piping correctly sized. If I were a betting man Carcrazy's Rinnai's had the gas under sized. Even if you tell the Mechanical contractor what you need, they usually have it piped incorrectly the first time they are involved with one.

[carcrazy]

Initially, my client's system was improperly piped. Techs repaired and the problem was better but still not solved. A pump was then added. Still takes an inordinate amount of time to get to the kitchen.

[TxGoats]

I have had mine for just over a year. We installed 2 Noritz tankless propane water heaters. I couldn't be happier, very efficient endless hot water. It takes about 45 seconds to get hot water in the shower and it doesn't stop until you turn it off. We probably could have gotten by with one unit since it is just the two of us but I was glad I had them both when we had a houseful at Thanksgiving. The initial cost was a bugger but I have gotten over that now and wouldn't want to go back to a tank water heater. I highly recommend them!

[Pearlbluebird]

Originally Posted by TxGoats

I have had mine for just over a year. We installed 2 Noritz tankless propane water heaters. I couldn't be happier, very efficient endless hot water. It takes about 45 seconds to get hot water in the shower and it doesn't stop until you turn it off. We probably could have gotten by with one unit since it is just the two of us but I was glad I had them both when we had a houseful at Thanksgiving. The initial cost was a bugger but I have gotten over that now and wouldn't want to go back to a tank water heater. I highly recommend them!

I agree, I recommend them all the time. A natural draft tanked hot water tank is only 55% effiecient. A direct vent style is only 57%. You are trying to keep 50 gallons of water hot 24/7. The instantaneous units depending on the manufacturer are 82 to 85% efficient. Always go one size larger. I like the Rinnai. They don't multitask very well. If someone is running the washing machine, not a good time for a shower.

[boater bill]

I would recommend a 4.5KW Bosch unit since you are in Florida and don't need that much temperature rise. A 3K will work but not warm it up much. Get ready for the power bill to go up every time you use it though. I cannot see how people think those things are "green".

[mrrat1]

I have been contemplating the change over for my house. I was thinking 1 unit for the kitchen/laundry room & powder room. They are together on the 1st floor. The second would be for the master & hall baths upstairs. I have a well w/tank & pump. I have natural gas for water heater in place now. Since you guys are in the Biz, does this sound like the way to go? What am I looking at for the conversion costs? Thanks for the inside scoop, Dave K.

[engineer]

no electric ever, not cost efficient.

[hobbygto65]

You might want to look into this, there is up to $300 Government rebate on the higher efficiency ones.

[Pearlbluebird]

Engineer's right only stick with gas. Dave your best bet is to have some contractors give you some quotes. By the sounds of what your describing there will be extra manhours involved.

[dancolkate]

You didn't say what type of heating system you have???

If you have a hot water boiler, you might checkout an indirect fired hot water tank. Basically, the (super efficient) storage tank becomes another zone off of your boiler.

Superstor is a good one

[67 455 Bird ragtop]

Originally Posted by Pearlbluebird

Engineer's right only stick with gas. Dave your best bet is to have some contractors give you some quotes. By the sounds of what your describing there will be extra manhours involved.

Yeah I figure I can use one of the LPG, propane, style heaters. Keep a 20 or 40 lb tank in the corner where the heater will be mounted. Keep it turned off when I don't need it. Also they are pretty cheap and easy to refill. And it's not like it will be used much each day.

["Me"]

Originally Posted by dancolkate

You didn't say what type of heating system you have???

If you have a hot water boiler, you might checkout an indirect fired hot water tank. Basically, the (super efficient) storage tank becomes another zone off of your boiler.

Superstor is a good one

This is what I have with infloor heat and my heating bills are small. There is nothing to break on them either so all you have to maintain is the boiler. Because there is no burner under the unit there is no tendency to fill up with deposits. Disolved minerals continue on through the system.

Ragtop, for your limited use I would not get too carried away, the payback would be a long time out. An electric with a handy switch for extended times of nonuse would be cheap, take up a relitively small space, require no venting, and be easy to install. Only you know how much you will use it.

Larry

[GonicGM]

I have propane tankless water heater in my house. Never run out of hot water even in power outage (has pilot). Most makes require stack through roof for exhaust. Mine is direct vent (through wall). It's also mounted to wall so no floor space used. Reply back on thread if you want more details.