on demand savings

how about anybody out there that changed their gas water heater to a on demand type water heater. any saving? and how much was the cost to switch? any surprises?

I changed mine 3 years ago, I got a big one because there are 6 of us in the house, my wife, 4 kids and I. I bought a Noritz, it was $1100.00 The 50 gallon that I was looking cost $500.00 so for $600.00 more I got all the hot water all the time. Additionally, there is a $300.00 tax credit.

According to the DOE web site, if you use 60 gallons of hot water a day and lp is at $1.25 (now $2.23) you will save $34.00/month. It is hard to tell that but one look at the needle on the old lp tank confirms that my gas use is down. It was down enough that my lp provider noticed based on their degree day calculations, when I should have been empty (down to 20%) I still had 35% left in the tank.

I currently only use propane for my dryer but last week I paid $4.25/gallon.

My question, if I temper my DHW with my wood boiler do I need a special on demand unit? I have heard that some have problems with water entering that is not cold.

Thanks in advance.

Eric

My brother has one in his house. The problem he has with it is that it never runs out so his wife and teenage daughter always take 30 minute showers. In his case the more efficient applicane is costinghim money in the long run because he's actually burning more fuel.

On my Noritz, I have the block type heating coil so the cold water comes in to the house, goes through the heating block that heats the water to 160-170 then a mixing valve that cools it back down to about 140. When boiler is running hot water heater does not fire.

My sister would regularly take showers until the hot water ran out. When I was younger, still living with my parents I had two options as a sibling who also required hot water.

If we had to be up at about the same time in the morning, I would try to get up first so that it wasn't a problem. If I happened to hear her start her shower first, I would get up as quickly as I could and run down to the other bathroom and get my 5 minute shower in while there was still hot water left. Her shower would run cold sooner, but at least I got my 5 minutes of hot water.

My other option was to slowly turn off the valve on the water heater so simulate running out of hot water. She would finish up her shower, and I could turn the valve back on and still have a little bit of hot water left. I know it seems sneaky, but it worked.

I wonder if you could rig up a timer valve on the on an on demand system to automatically simulate running out of hot water.

-SF

Better yet, rig up a timer and a delay relay - after say 10 minutes the timer goes "DING"; 30 seconds later the hot water shuts off.... %-P Or maybe get one of those coin-op timer valves like they use in campgrounds?

Gooserider

My niece likes to take long showers, so long sometimes she falls asleep. I go to the basement and turn off the hot water and she finishes up real quick!

Derbygreg:

Thats "cold" pun intended