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PROBLEM with new tankless water heater

Last year, I upgraded my entire HVAC system (partially located in the utility closet in my 1-bedroom condo). Because the new unit was larger than the old unit, I was forced to replace my water tank with a tankless unit. Despite the fact that I did quite a bit of research and Q&A with the company from whom I purchased the unit (Stiebel-Eltron), the tankless heater is not providing sufficient water pressure at the temperature at which it is set (117-120F).

Unfortunately, new space limitations make it impossible to revert back to a traditional water heater (with a tank) without replacing the entire HVAC unit, which would be extremely expensive.

The tank manufacturer suggested I upgrade to a more powerful unit, but I'm told this isn't possible because the power to my main breaker is less than what the tankless unit requires. The higher powered tankless unit requires 3x50 amps; at my main breaker I have 125 amps. The unit currently installed requires 2x50 amps.

Has anybody ever found themselves in a similar situation? Is this problem solvable?

Re: PROBLEM with new tankless water heater

The way tankless water heaters work is that they restrict the flow of water to have instant hot water available. in other words if the you required more water than the unit can produce it will shut down volume of water to the capacity it can produce. I an not a fan of tankless hot water heaters. Lets say it is sunday after noon and your wife wants to run the dishwasher. your son wants to run the clothers washer for a football uniform and you want to take a shower. with tankless hot water tank nobody will get water.

Re: PROBLEM with new tankless water heater

To be able to install a bigger unit, you will need to upgrade your panel.

Another unexpected expense...

Re: PROBLEM with new tankless water heater

This goes beyond the panel, it goes all the way out to the distribution transformer. If a single distribution transformer serves multiple customers, then this can affect all of them too.

When the current tankless water heater kicks on, do the lights in your condo dim a little. If they do, they are also dimming for anyone else who shares that transformer. A bigger unit will only make matters worse. If you go with a bigger unit, not only will you need a larger panel, you may need larger service wires and the utility company may need to install a larger transformer. Who will pay for that and who will pay for the higher no-load (core) losses of a larger transformer?

I think you need to look for alternatives. Do you have an attic that the water heater could be located in? How about a corner cabinet that a small tank type water heater could go in and be out of the way. You might need two corner cabinets to supply all your hot water needs.

Is a gas tankless water heater a possibility? They work a little better than the electric ones. In my opinion, electric tankless water heaters should be banned.

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