Propane Hot Water Tank heater or Tankless? Help me decide.

Scotty Dive · Mar 3, 2014

I am considering swapping out my 40 gallon electric for a propane fired solution. Here is my situation:

- Electric 40 gallon is 13 years old - no problems but thinking I should be proactive rather than reactive in case it fails. Takes 4500 watts to work and eliminating this for a propane solution will free up needed wattage for my generator.
- Water is from well and is good quality and there is a whole house filter - not softened - no need. Current hot water heater is working fine. Has only been drained a few times and believe it has the original anode (or whats left of it)
- Rarely run out of hot water.
- Should be in this house for another 10 years minimum
- Currently have two 120 gallon propane tanks for furnace
- Live in the Northeast, 40 year old two story home, mechanicals are in basement - 4 people
-

My thinking is this:
- My going from electric to propane will save me considerably in energy costs and it will allow my generator to power the whole house without having to manage power loads like we do now.
- I am looking for ease of use and if there are increased maintenance costs it needs to be offset by some considerable gains
- Will consider the tankless - but I see increased up front costs, increased maintenance, specialized troubleshooting expertise needed, and some folks not happy with hot water delay and cold water sandwiches.

So - I know what I am getting with a 40 gallon propane fired hot water tank. What are the benefits of considering tankless and is the premium to purchase/install worth it in my situation?

2458n · Mar 3, 2014

With the current propane costs it is better to take the wait and see attitude. I watch This Old House and you know that they push the benefits of the tankless with its constant supply of hot water. It would seem that not having to heat the water 24/7 would make your choice very simple.

aczlan · Mar 3, 2014

To get around the "hot and cold sandwich" one could put a small (2-3 gallon) electric hot water heater inline after the on demand heater. That will "smooth out" the "sandwich"

Aaron Z

kraftykeltic · Mar 3, 2014

look into the heat pump water heaters. cuts the electric use dramatically, and does not curtail hot waster use. can be stand alone or add on. initial cost vs cost of use is the deciding factor. When parents lived in Florida they had the AC tied to the hot water, which was endless and a waste produt of the AC

Looking4new · Mar 3, 2014

Check the temperature of the water coming out of your well. I have read that tankless water heaters only raise the temperature of the water 40 degrees.

wrangler6831 · Mar 3, 2014

I'm going on 10 years with my two natural gas tankless water heaters and would def install another if these were to go bad. Mine have pilot lights and require no electric so the newer ones may be a little more efficient. As for raising the temperature 40 degress, I cant see that. I just got city water installed and previously had a well and didnt notice any difference at all. The reason for having two was so I can isolate the ground floor from the upper if I ever needed to do so. Dont listen to the people that say "I have heard or I have read" I'm speaking from real world experience.

Rich

Scotty Dive · Mar 3, 2014

2458n said:
With the current propane costs it is better to take the wait and see attitude. I watch This Old House and you know that they push the benefits of the tankless with its constant supply of hot water. It would seem that not having to heat the water 24/7 would make your choice very simple.

I am following another thread on TBN and I see that the prices have started to fall. I alos have a call into my supplier to get his take on the market. Everything I have read was that this was due to a shortage from farmers using huge amounts of propane to dry their crops this past fall. True? I would believe that the fluctuations this year will make dealers "smarter" in buying their futures for next year and beyond.

aczlan said:
To get around the "hot and cold sandwich" one could put a small (2-3 gallon) electric hot water heater inline after the on demand heater. That will "smooth out" the "sandwich"

Aaron Z

I have read that too. The first thought that comes to my mind is why would I want to add a second system and point of maintenance and failure to a system that has flaws? Is the tankless that much better and cost effective that I would endure the increased equipment/maintenance/costs?

MechE1 · Mar 3, 2014

I've had a Bosch tankless for 6 years now. 199000 BTU, NG. NO pilot. Well water filtered x 2. I've had no issues and love it. It never runs full power. Some things to consider, and this may be specifc to my model. Water Pressure drop. They are sensitive to pressure and will drop out under 40psi. Gotta keep that dynamic pressure up. Cost of exhausting. The exhaust tube is crazy expensive. If you have a long route, be ready for sticker shock. "extra" installation costs due to cleanout valves etc. Usually have to run an extra 6 seconds at a .6 gpm I think for it to kick on. Honestly, I was worried this would be an issue, it isn't. Overall, very pleased. I love not having the pilot light, or a hot tank of water on hand. Oh yeah. I never run out of hot water. If you are into recirc. valves and the like, it becomes more difficult. I would do it again.

OKnewguy · Mar 3, 2014

We have this unit Bosch 125B-NG AquaStar Natural Gas Tankless Water Heater - Amazon.com It is not available anymore but there are similar ones to replace it. Most of the time I hear about problems with the tankless it has to do with overly complicated electronics. This unit was really basic and the main reason I choose it was to decrease the size of the water heater closet. I have had it now for 12+ years and love it. The farthest faucet takes some time, but you get used to it. It does drop the pressure slightly on the hot water side, which makes it pretty pitiful to try and run two baths at once, but to showers or a shower and a bath are no problem. I love it!
Dave

V1Rotate · Mar 3, 2014

I have a hot water baseboard heating system that also does the domestic hot water, it is all tankless and runs on natural gas. I love it, cheap to run. I sometimes experience the "cold water sandwich" during the winter months. I live in CT so the weather has been brutally cold (like everywhere else) so the temperature of my incoming city water is so cold it will hurt your hands if you hold them under the faucet.
When taking a shower, the water starts off nice and hot but after about 30 seconds it will cool off a little so I adjust the temp control, then a few seconds later the water temperature stabilizes.
This only happens in really cold weather and is a little bit annoying but overall I am very happy with it.