Unlimited hot water

[RandyBell]

With the A.O. Smith hot water tank unit I put in the house last year it would NOT take much to be better at producing hotwater. First of all the hotwater tank is less than 10 feet from the bathroom and shower, we have 1/2" copper pipes with the hot lines insulated and to take a shower you have to turn hot completely open and trickle the cold to have a decent shower! The biggest problem I could find with the unit is even though it has 1/2 couplers they neck them down to 3/8 inside the unit. If it wasn't for the cost of purchasing another new unit I would chuck this one in the scap pile! I talked to a plumber about the tankless and with all of the descaling that you had to do I just couldn't see it being cost effective to operate, who wants to put out that kind of money only to triple your work load.

Just my 2 cents

Randy

 

[PineRidge]

I have thought about this kind of re-circulating solution, however; I am going to use PEX and a manifold to distribute to the end points. There is no way to effectively recirc. Even if I create a loop for recirc off the manifold, I would only keep the line from the HWH to the manifold hot, all of the other lines are still cold.

In your case I don't think a manifold would work with the loop. What do you actually save running a PEX line from the manifold to each faucet. Seems to me like you would use more PEX tubing + the cost of the manifold. Why not just run a 3/4" line from one end of the house (from water heater) to the 1st faucet then a T to the next faucet and so on down the line. When you get to the farthest faucet use another T but this time come back to the cold water inlet on the water heater. The return loop line can be 1/2" if you like. You will need a couple of spring check valves and a pump but you'll always have instant hot water when you need it. The pump installs in the loop back to the water heater.

 

[PineRidge]

The circulator pump arrived and is now installed. I also insulated all the hot water lines to keep heat loss at a minimum. Still waiting on the Insteon controller that will tie into our home automation system to cycle the circulator pump.

 

[sdkubota]

Just to add some perspective...it takes approximately 43' of 3/4" pipe to hold 1 gallon of water. It takes 96 feet of 1/2" line to hold a gallon of water. My point is while you think you are wasting a lot of water waiting 20 seconds for the faucet to warm, you may be surprised.

 

[dmccarty]

Just to add some perspective...it takes approximately 43' of 3/4" pipe to hold 1 gallon of water. It takes 96 feet of 1/2" line to hold a gallon of water. My point is while you think you are wasting a lot of water waiting 20 seconds for the faucet to warm, you may be surprised.

THAT is some danged good information! I never even thought about how much or little water was in the pipes but just figured, "waste not, want not." :laughing::laughing::laughing: I still try to use the cold water for something but I don't think I will "sweat" waiting for the shower to warm up.

Thanks,
Dan

 

[Allee]

THAT is some danged good information! I never even thought about how much or little water was in the pipes but just figured, "waste not, want not." :laughing::laughing::laughing: I still try to use the cold water for something but I don't think I will "sweat" waiting for the shower to warm up.

Thanks,
Dan

My only issue is that if I have to run downstairs to the garage to reset the water-heater when I've already run water and leave it running for the duration of my trip. I've wasted that small amount of water, a small amount of electricity, what little amount of time it takes me to start the heater, and mostly just the inconvience. Yes, I appreciate that we "all" have to wait for hot water no matter what, but my episodes are just a little more detailed especially when I'm all lathered up and in the middle of a final rinse. !@#$%

 

[Artisan]

IMO,

I tell folks this;

If you have the mean$ to purchase and maintain a tankle$$ type of $ystem
by all mean$ do it, it's only money, right?

But-Some-However;

If your on a budget DO NOT EVEN CONSIDER IT, your not going to save
anything in the long run. The maintenance alone could eat you alive
and skilled technicians capable of servicing it will cost you BIG, IF you
can find a QUALIFIED technician in your county and IF they REALLY
know what their doing!

I get lots of calls to try to fix these systems, 9.9 out of 10 times
it is a sub standard install... The look on peoples faces when I tell
them the facts is disturbing, I HATE being the bearer of bad news....
It is what it is...

BELIEVE IT Caveat Emptor

 

[aczlan]

I must be lucky on our system...
We have a Stiebel-Eltron Tempra 24 (electric tankless on demand) which the previous owner neglected for several years, but (knock on wood) it has worked very well for us over the last year.
We are on city water and I flushed it with vinegar this summer, but otherwise I dont think that it has been touched for 2-4 years. My uncle is a plumber down on Long Island and he is a big fan. He has been replacing domestic HW heaters and boilers with them for several years now and claims that the people who have them (most running on NG) have cut their utility bills with no ill effects.

Aaron Z

 

[PineRidge]

Guys they have been using tankless water heaters in Europe for 30+ years. I would just bet the manufacturers have seen and dealt with every problem you could ever imagine. Equipment improvements are always being made but if you install anything sub-standard it will most likely under-perform. If your technician can't or doesn't know how to service your equipment then you need to call another co. it's just that simple.

I consider myself a good HVAC tech, grew up in the industry, started when I was 16, that was 47 years ago and have seen a lot of change in the industry. If I run into a problem where I might have little or no experience I know who to call and talk with to get the right answers. I have seen good, bad, and ugly, and unfortunately they all claim to be techs. In other words if your on-demand heater is giving you grief maybe you shouldn't be pointing your finger at the heater.

 

[schweizer]

For those who are writing that on-demand water heaters can't keep up with 2 showers, or 1 shower and 1 dishwasher, etc., maybe their water heaters are undersized. Like I wrote a few posts back, we have a Rheem RTG-84DVP. We often have 2 shower heads on simultaneously -- no problems.

You have to look at the Delta-T flow rate curves for the heaters before buying to calculate it that heater will handle the flow of 2 faucets at XX delta-T. Example: incoming water temp is 45 deg and output goal is 120 deg, therefore delta-T is 75 deg. 2 faucets at 1.5 gpm = 3 gpm minimum. Our water heater does 4 gpm for that delta-T on the graph.

Could it be that some unsatisfied customers just bought what the store had on the shelf and now it underperforms?

Marcus