New hot water heater options, Tankless vs Tank... Electric vs Propane.

[Alan L.]

I have an Rennai unit - propane and it works great. Uses about $35 a month of propane as far as I can tell. I like taking a long shower with no worries about running out of hot water. My wife also has one of those big corner jacuzzi tubs that holds like 80 gallons of water, so it is nice not to use up all the hot water filling that thing up.

Takes up no room - it sits in an outside wall. I have clean the input screen every few weeks. The only drawback I see is if the power goes off no hot water because while it burns propane the ignition is electric. And there is no hot water in the tank to use. I don't remember the cost in the new house - seems like it as $1500 but that might have been the extra charge vs a conventional water heater.

 

[CliffordK]

I had a tankless hotwater heater for a while.

It had an exhaust fan. I'm not sure if they all do. But my biggest complaint was that I had a tendency to turn my water on and off. With every on/off, it would cool the water in the water heater, and always hit me with a blast of cold water. I found it to be quite annoying.

Solar assisted hot water sounds like a great idea. Hopefully I'll get one installed soon, although much of my roof gets shaded off and on.

 

[sodamo]

Yea, solar assisted. Still have dreams of solar with propane on demand as backup for main part of house. When we built, it was about $4k just for the solar part after rebates etc. someday...

David Sent from my iPad using TractorByNet

 

[aczlan]

I had a tankless hotwater heater for a while.
It had an exhaust fan. I'm not sure if they all do. But my biggest complaint was that I had a tendency to turn my water on and off. With every on/off, it would cool the water in the water heater, and always hit me with a blast of cold water. I found it to be quite annoying.

I agree, We have run into that and the solution (from what I hear) is to install a small (ie: 1-3 gallon) electric tank after the on demand heater to temper those changes, or leave just enough water running to keep the heater on.
One thing I will need to check is that it can handle 120+ degree input temperatures in the winter when we run the indirect from the oil or wood boilers.

Solar assisted hot water sounds like a great idea. Hopefully I'll get one installed soon, although much of my roof gets shaded off and on.

Have thought about solar, but I dont see it as workable right now. Perhaps after we redo the roof in a couple of years...

Aaron Z

 

[sodamo]

...
One thing I will need to check is that it can handle 120+ degree input temperatures in the winter when we run the indirect from the oil or wood boilers.

Have thought about solar, but I dont see it as workable right now. Perhaps after we redo the roof in a couple of years...

Aaron Z

Just plumb in a bypass?

David Sent from my iPad using TractorByNet

 

[aczlan]

Just plumb in a bypass?

Could be done, the benefit to running them in series is that if we somehow run through the 40 gallon indirect tank, we dont run out of hot water, and we dont have nasty water stagnating in the indirect hot water heater over the winter. Also, if something goes wrong and it turns on, there isn't a closed section of pipe to generate pressure, possibly make steam and explode.

Aaron Z

 

[Hammy]

I have a Rennai tankless system. It is nice for the fact of not having to worry about running out of hot water but they do like the propane, A LOT! I figure we are up around $400 a year at least for propane and some years more depending on the price. I've been running ours for over 6 years with no major issues that I can think of. Another thing I don't like is every time somebody turns on the hot water at a faucet, the unit kicks on even if its brief. Now I know that's what they're suppose to do it just drives me nuts when my wife wont need or wait for the warm water but turns the water heater on regardless so the unit fires up then runs through the whole cool down cycle every time the valve is opened for hot water. That is just me though hating to hear the unit fire up for no reason.

I might be more inclined to go with dual 40 or 50 gal tanks next time. However, I've never looked into seeing what they cost per year in comparison.






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[PsRumors]

I'd have to get up in the attic to see the brand of tankless water heaters we have but we have two running off propane. We love them! They are both the old style mechanical units with a pilot light, no electronics.

One failed to fire a few years ago after 10 years of use and I pulled it down and repaired it, the seals in the flow sensing valve needed replaced. Beyond that, just a good cleaning every two years to keep the pilot light screen clean and they run like a top.

I don't know that I would go with one with electronics but now days I don't think you have a choice.

 

[buickanddeere]

Time of use power or flat rate? An electric tank heater with a timer on the bottom element to operate at lowest rate is cheap enough. Low enough current demand to operate from a modest generator too.

 

[grsthegreat]

Oh..i also forgot the MAJOR disadvantage of the on demand system.......it wont operate on a looped hot water system.

I had my house plumbed for instant hot water. Theres a small 1/15hp pump that is constantly recirculating the hot mater during the times of day that demand it. I get hot water at any tap within a few seconds. No on demand system can operate this way unless some complicated holding tank system is installed.