Lvscott said:   sgogo said:   Just a few notes on these:

1- If you have gas coming into your house, I would not suggest changing to an electric HW heater, even an instantaneous one. Anual energyu expenses will usually go up, except in very low hot water usage scenarios.

What do you base this on? Where I live some people have gas tank water heaters and some electric. My gas bill went down $20 a month when I installed the tankless but the electric bill did not go $20 higher. It is a lot more energy efficient to heat water only when you need it than to constantly waste power reheating a tank of water that sits there waiting to be used.

sgogo said:   
2- If you have hard water, research a little on these. The descaling process is difficult. Tank type HW heaters are more forgiving of not maintaining them (which most people don't).

I have never heard of anyone descaling either of these. I don't even think there is a process for a tankless other than cleaning the inlet filter. As far as forgiving, my old tank heater flooded the room it was in. That won't ever happen to me again.

We have a tankless gas heater. Yes we have to descale a few times a year however it's not a difficult job. video directions

Also everything I read when we chose ours a few years ago said the gas tankless systems worked better and cheeper than electric ones so I'd agree if you already have gas going into you're house you'd want to put in a gas tankless not an electric one.

Lvscott said:   sgogo said:   
5gpm is example flow for two appliances... typical, minimum design criteria.Otherwise, running a sink in another room will affect shower.

Govt reg is 2.5gpm per shower and many people remove the restrictor inside.

Use the calculations and figure out how many gpm you will need.

Another thing people don't realize is that if you run 5GPM with a 50 gallon tank heater, you are out of hot water in 10 minutes. With a tankless, depending on how cold it is where you live and the size unit you buy, you may only be able to run one shower at a time, but you can run it for 24 hours if you want to and still have hot water.

Three people in a family taking one shower after another with a tank water heater will run out of hot water by the third shower. This won't happen with a tankless.


I am not telling you that tankless are bad, just shedding light on the issues.

With a tank type heater, the water temp can be brought up well over 105F. This allows you to use the water to mix with cold, so the 5 gpm when running two showers simultaneously will last well over 10 minutes, since you are not using 5 gpm of hot water, but mixing in some cold water.

Also,there is a recovery rate that most people do not understand. As the water is being drained from the tank, the burner fires up, and begins reheating the tank right away... The better the recovery rate of the tank, the quicker it is ready for the next bunch of showers. Some units are able to recover quick enough that while people are toweling off, they reheat enough for the next shower, even if they were emptied completely.


bones774 said:   jockum said:   ...I personally am waiting for mine to break so I can replace it with a power vent conventional gas heater,as I do not believe there are any net savings because of the increased water consumption of waiting. Just my .02

What does the power vent offer you? I thought the power vent was just used for unusual install applications(e.g. severe exhaust bends or long exhaust vents). Just wondering?

Power vented units have two other advantages... they are usually a little more efficient and they allow you to use outside air for combustion, which means no chance of reversing the flow of CO due to bad balancing of airflows, as well as not requiring vented doors on the room to the mechanical space.

On the downside, they can make noise when running that is very hard to mitigate... it is a high pitched whine from some manufacturers, and if near or under living space, its annoying.


taxmantoo said:   This will cut your hot water consumption.
I bought one last year, other than having to turn up the temp a little more than with a high flow head it's great.
Actually puts out about 1 GPM on my water pressure.

Niagara 1.25GPM shower head.

Sounds like a fog machine.

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