Home>Discussions>PLUMBING>Problem with tankless water heater: need to have two taps on to turn it on
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LilliK
Problem with tankless water heater: need to have two taps on to turn it on

Hi all! I'm a tenant in a wonderful old house, and we got a new tankless water heater about a year ago. There's a bit of a problem with it that I've complained about several times but the plumbers seem to be unable to fix. Here's the issue:

Neither the kitchen tap or the bathroom sink tap get hot water when they're alone. So if I want to wash my face with hot water, I need to turn on the shower. If I want to wash dishes, I also need to turn the dishwasher on, to get hot water. I can run the tap for 15 mins and just get cold water, and if I listen to the heater, it's not turned on.

The plumbers have tried to figure it out, but of course, when they're here, usually to fix something else, all sorts of faucets have been run, so there is hot water..so they think I'm crazy.

What I think is that there's not enough water pressure to turn the heater on when it's just the taps. They both get low water pressure.

The water heater is a Takagi T-K Jr.

Should I contact the manufacturer to see if there's something I can do on the device so it would turn on more easily?

Or should I just continue running two taps and waste water?
Please help, my landlady and plumbers think I'm making this up, but I'm not!

dj1
Re: Problem with tankless water heater: need to have two taps on to turn it on

Who installed this tankless water heater and is it the right size unit for the house?

Why don't you invite the landlord to see for himself what the water heater is doing and not doing?

Calling the mfg at this point will get you nowhere.

let us know.

HoustonRemodeler
Re: Problem with tankless water heater: need to have two taps on to turn it on

Your flow sensor needs adjustment. Call the Manufacturer or look in the trouble shooting guide.

LilliK
Re: Problem with tankless water heater: need to have two taps on to turn it on

Thanks for your comments! To respond to the first one, yes, I have told my landlady and had the plumbers over, but the problem doesn't happen when they're here. Which makes them think I'm just too impatient to wait 10 secs...

But after getting the right word I was looking for, "flow rate sensor", I was able to read about it on the user manual for the device I found ****** – installer never gave me a paper copy of the guide. So the default flow rate of the device is 0.75 GPM. Which apparently is too high for the bathroom and kitchen faucets, since they don't activate the heater.

So I called Takagi, and they said it's an easy fix to adjust the flow rate sensor, and they even gave me a phone number for their suggested plumber.

Now I only need to convince the landlady that this is a necessary fix! :D

plumbingjim17
Re: Problem with tankless water heater: need to have two taps on to turn it on

Yep sounds like you got it figured out one other thing I have seen cause this problem is plugged aerators on the faucet try removing them and putting in new 0.75 should turn on with a regular faucet I would try removing the aerator and replacing it I bet that will fix your problem.

Ben & Munson Mech Plumbing
300 N 100 W
Lehi, UT 84043
(801) 960-1766
http://www.benfranklinplumbingut.com

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