3 posts / 0 new
Last post
Tankless Hot Water

My Hot water tank (50gal) has given out and am researching tankless electric system. Anyone have good or bad experiences?
I found the Bosch tankless has had too many problems. Anyone heard of Niagaratech industries?

Re: Tankless Hot Water

First you need to have 60 AMPS to run most units. The max flow rate you can get is 4 gpm . Open two faucets at the same time and your out of hot water. So don't try to take a shower and run the clothes washer at the same time. If you can live with that then go for it. We have installed a few of these units but in most cases the customers were not happy with them.


Re: Tankless Hot Water

What size transformer do you have supplying electricity to your house? Most homes have a 15 kVA unit dedicated to their house, some have larger transformers but share them with neighbors.

When you add a load to a transformer, the output voltage will go down some due to the internal resistance of the transformer windings. The amount of drop increases exponentially with the increase in the load. A 15 kVA transformer is rated for 62.5 amps. Some of these water heaters draw 90 or more amps. This would greatly over load your transformer causing a serious voltage drop to occur.

Now comes the dilemma. Your utility could install a larger transformer to keep the voltage drop down, but it will cost them a lot more money to do so. The larger the transformer, the higher the core loss. The core loss occurs 24/7 and is before your meter.

A larger transformer on your house whose capacity is only used for a very short time reduces the electrical system efficiency. You could actually increase your "carbon footprint" because of that. It also means that everyone else is paying for your small savings. I think that anyone who gets one of these should pay for primary metering, that is they pay for the ***** going into the transformer, not just what goes out. I don't think a utility can do this to a homeowner because the public service commission would simply not allow it.

If you have an electric water heater, a modern, well insulated water heater will only use about $2 a month to store the hot water. The biggest cost of the water heater is making replacement hot water for the hot water you use.

If your goals are to save money and reduce your carbon footprint, get the smallest water heater you can get by with, get a well insulated model, use low flow shower heads and use the water heating feature in your dishwasher.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.