Tankless Water Heater Update
Last month we had a tankless water heater installed.* Here's what I've found.
The total installation cost was 1599 + $20 to dump the old water heater at the dump.
In the month prior to installation we used 38 gallons of propane, and in the month since installation we've used 21 gallons.* Note however, that it has been warmer this last month, so we've hung laundry out instead of using the dryer, and we also started washing in cold water.
Total savings from these three changes was 17 gallons, which at a price of $2.00 per gallon is $408 per year.* In addition, the propane price fluctuates between about $1.11/gal in summer and $2.63 in winter.* So, if we can make it through the winter months without buying any propane, we'll save significantly more.
Old: 38 gal/month * 12 * 1.66 (avg price we've paid) = 756.96
New: 21 gal/month * 12 * 1.20 (estimated summer price) = 302.40
Annual Savings: $455
Payback in 3.5 years
My main concern was that with the new system, when we were using several hot water devices at the same time, the flow/temperature would drop.* This has not happened -- we've had plenty of hot water.
I expected that the amount of time for the hot water to reach a faucet or the shower would be the same as with the tank system.* However, I didn't realize that hot water from the tank in the old system diffused into the the pipes somewhat.* As a result, with the new system you have to wait longer for the water to get hot.*
In the kitchen it takes 32 seconds before you get full hot water.* *So, if you want to wash your hands with warm water, you have to wait.
Bathroom faucets about the same.* But for some reason I haven't yet figured out, the shower doesn't reach full temperature for 2 minutes.* It's usable after 30 seconds, but not hot (120 degrees) until 2 minutes.* Luckily we don't pay much for water.
The delays are a bit of a bother, but not too bad.* I'll probably install a small undersink heater in the kitchen for instant hot water.
Also, we will never run out of hot water when multiple people take showers.
Overall I've concluded that it was a worthwhile investment.