School me on hot water heaters...

pkovo

Well-Known Member
#21
No one suggesting indirect fired water heaters?
https://www.amtrol.com/product/boilermate-indirect-fired-water-heaters/

example: https://www.homedepot.com/p/Amtrol-BoilerMate-41-Gal-Indirect-Fired-Water-Heater-CH41Z/205193077

Honestly, I would echo what Michael.su said. It is cheaper and easier to swap out what is already in place, unless you are wanting to update the system.
I have one of these 41 gallon Boilermates set as priority connected to my oil fired boiler. I've been very happy with it. We only have two baths, but there are 5 of us, and I'm the only guy. We don't pay any attention to running multiple hot water items simultaneously, and we never run out of hot water. It seems to heat it back up as fast as we can use it.
 

jnos

Well-Known Member
#22
You can run a tankless water heater with a buffer tank. It's a more complex system, so make sure your plumber isn't a dope. the buffer tank allows for handwashing/other short use hot water demand without the system kicking on.
I think this depends on the dish washer.
Correct. My dishwasher (Miele) can take a cold water hook up.
 

one piece crank

Well-Known Member
#23
I enjoyed reading though all this and I like "new" and "technology", but I can't see a multi-person home scenario when on-demand makes any sense (at lease for me). Seems like fitting a square peg in a round hole. I say drop a new water heater in every 10-years-or-less and you're ahead of the game (cost, consumables, hassle of you bearing the full burden of understanding the system).
 

Matt_

I Get Jokes
#25
Yeah I'm not 100% sold on tankless yet, still a lot to weigh.... right now I'm leaning towards a high efficient tank unit for a quick swap that my FIL and I can knock out in a few hours, then seeing if some of these hybrid approaches make sense for down the road.

Silver lining I guess is the property failed septic inspection yesterday so I doubt we'll be closing the 28th :confused:
 

fidodie

Well-Known Member
Staff member
#26
Yeah I'm not 100% sold on tankless yet, still a lot to weigh.... right now I'm leaning towards a high efficient tank unit for a quick swap that my FIL and I can knock out in a few hours, then seeing if some of these hybrid approaches make sense for down the road.

Silver lining I guess is the property failed septic inspection yesterday so I doubt we'll be closing the 28th :confused:
is there already a hole in the wall for the intake/exhaust? (which is cool, they use the exhaust air to heat the intake air on the last one i installed)
this also prevents creating negative pressure in the house. which is a bonus. i
 

ryderX

JORBA Luddite: KVSP Bulldog
JORBA.ORG
#27
On demand water heaters are great when they work correctly. Basically unlimited hot water and no energy loss since you aren’t storing water. The problems I see regularly that can make them a bad choice are
0. When they don’t work finding a well trained service tech is usually a real PITA.
0. And then waiting for the highly specialized replacement parts usually takes a few days.
0. They need to be maintained regularly and that usually requires cleaning- de-liming of the heat exchanger yearly or based on the usage load
0. you also need very good house water pressure if you’re planning on using more than one faucet or appliance at a time.
0. You also need to assure that you’re supplying gas utility is supplying the gas at a pressure greater than 4-5” of W.C. and that your gas line running to the on demand heater is size correctly and is also a home run from the outlet of the gas meter.
 

Matt_

I Get Jokes
#28
is there already a hole in the wall for the intake/exhaust? (which is cool, they use the exhaust air to heat the intake air on the last one i installed)
this also prevents creating negative pressure in the house. which is a bonus. i
The current water heater vent goes straight up with the HVAC vent.
 

capedoc

Well-Known Member
Team MTBNJ Halter's
#29
Is tankless hot water and on demand the same thing? When i bought my house i had the hot water on demand thingy and it kind of sucked. I got rid of it and replaced with an electric hot water heater which has been great.

The problems I had were that I kept having to get it cleaned because it was getting plugged up with lime scale incredibly fast. I'd loose water pressure until I eventually had no water pressure at all. Each cleaning was $800!! 6 months would go by and it would need to be cleaned again. I'm on top of my water softener but the well water here in the sourlands is just really hard I guess.

Other issue I had was that I was burning oil all year round just to heat water. Now I can shut my boiler off for 6 months. The additional electricity usage doesn't come close to the oil usage.
 

fidodie

Well-Known Member
Staff member
#30
Is tankless hot water and on demand the same thing? When i bought my house i had the hot water on demand thingy and it kind of sucked. I got rid of it and replaced with an electric hot water heater which has been great.

The problems I had were that I kept having to get it cleaned because it was getting plugged up with lime scale incredibly fast. I'd loose water pressure until I eventually had no water pressure at all. Each cleaning was $800!! 6 months would go by and it would need to be cleaned again. I'm on top of my water softener but the well water here in the sourlands is just really hard I guess.

Other issue I had was that I was burning oil all year round just to heat water. Now I can shut my boiler off for 6 months. The additional electricity usage doesn't come close to the oil usage.
1. there is a sacrificial anode for the tank which is supposed to go "first" - then be replaced before the salts attack the heating element and
nipples. you might need to make this part of your 3 month maintenance, unless #2.

2. make sure the inlet and outlet pipes are bonded together with a copper cable just above the water heater. if there is any electric ground finding its way to the water heater, it will create a current in the water, and it destroy it damn quickly. the pipes are insulated from the water heater with a dielectric coupling (unless #3), so the only way through is via the water. esp being electric.

3. make sure they used dielectric couplings, or the unit has built-in dielectric nipples. otherwise it is part of your electric grounding system (not good)

4. it may be cheaper to add a water softener, then to destroy you water heater. it will also save the dishwasher, washing machine, and faucets. don't soften the water to your ice maker, or primary source of drinking water, or plant water. it tastes crappy. at a minimum, soften your hot water. your clothes will thank you.

--

other than low flow failure, what was wrong with your demand system? mine works great, other than exceeding its limits if someone runs the water, but then again, i have a well, so the input is also limited.
 

capedoc

Well-Known Member
Team MTBNJ Halter's
#31
4. it may be cheaper to add a water softener, then to destroy you water heater. it will also save the dishwasher, washing machine, and faucets. don't soften the water to your ice maker, or primary source of drinking water, or plant water. it tastes crappy. at a minimum, soften your hot water. your clothes will thank you.

--

other than low flow failure, what was wrong with your demand system? mine works great, other than exceeding its limits if someone runs the water, but then again, i have a well, so the input is also limited.
Thanks for the info Pat. You know your shit. I have no idea how to only soften hot water. As far as i know, the softener tank is for all water in the house. No idea how to separate so only certain water sources get the softener like you suggest. Pretty sure iv'e been drinking softened water for the last 5 years and it tastes fine to me...but then again all water tastes the same to me. The water on Staten Island is repulsive however. Staten Island is the exception.

I didn't like having to pay $800 to clean it every 6 months. thats a lot of freaking money. The water pressure was really bad and would progressively get worse between cleanings. And it burned a lot of oil.
 

fidodie

Well-Known Member
Staff member
#32
Thanks for the info Pat. You know your shit. I have no idea how to only soften hot water. As far as i know, the softener tank is for all water in the house. No idea how to separate so only certain water sources get the softener like you suggest. Pretty sure iv'e been drinking softened water for the last 5 years and it tastes fine to me...but then again all water tastes the same to me. Although the water on Staten Island is repulsive. Staten Island is the exception.

I didn't like having to pay $800 to clean it every 6 months. thats a lot of freaking money. The water pressure was really bad and would progressively get worse between cleanings. And it burned a lot of oil.
water, pizza...i see a pattern ;)

i think i read your post incorrectly - thought you were having trouble with the tank!!!
 

capedoc

Well-Known Member
Team MTBNJ Halter's
#33
i think i read your post incorrectly - thought you were having trouble with the tank!!!
Hahah no the tank is great. But your advise is good and Im actually going to check all those things. So, thanks for your input. Again, you know your shit.