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I actually have a question about a tankless water heater;

Customer Question
I actually have a...

I actually have a question about a tankless water heater; can you help?

Contractor's Assistant: How long has this been going on? And how severe is the problem?

Its a powerstart electric water heater and the water turns cold then scalding hot

Contractor's Assistant: Do you plan on doing the work yourself?

It depends

Contractor's Assistant: Anything else we should know to help you best?

I have model number, etc? its in a rental property (tiny house) adn just started yesterday

Submitted: 10 months ago.Category: HVAC
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Answered in 13 minutes by:
9/25/2017
HVAC Technician: Phil, Mechanical Engineer replied 10 months ago
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 9,799
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial
Verified

Hello, there is a 'flow switch' inside the unit that turns the power to the heating elements off if the flow gets too low, so you can get this ON OFF effect as you regulate the hot water at your shower for instance.

Try turning on two hot taps at once and see if that allows the water to stay hot or not.

.

We can go from there without a time limit, In depth with as much detail as needed , after you rate this answer:

Select the 'finish and rate your expert link' near the top of your page and click on it.

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I am a retired mechanical engineer and HVAC/electrical/ refrigeration and boiler contractor ... with 56 years in this business. The last 20 of those years consulting for major firms nationally.. and with over 8,000 questions answered here since 2009, with a 98.5% satisfaction rating.

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All I ask is please respect me and my input by selecting the***RATING LINK***at the top of your page, that is the only way I am credited through the site. Rating does not affect your charges nor ability to refund if not satisfied.

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If you need to be coached through a full diagnosis/repair,and wiring etc. for up to two days, and wish to be trained to use test instruments...... that goes well beyond' Just a simple Answer' of course, and goes beyond what most other experts here offer.....rate my answer so far positively.. . and I will deliver that training and coaching to you All on the same dime so to speak.

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Lacking a positive rating I can spend days helping a person at my own expense and loose my shirt, shorts and socks on the deal.

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Attach a close up photo of the wiring diagram glued to the inside of the blower access door and I will mark it up with trouble shooting instructions then follow up with step by step training and coaching until you have a solution.

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Photo must be exceedingly well focused. Use the 'add files' link next to your send button to get the photo to me.

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Tell me a little about your technical background and instruments on hand so that I can coach you most effectively. We can go from here.

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Customer reply replied 10 months ago
its a small unit for a tiny house, model number 45-550303 i need to walk down to the house and try to open the case of the water heater its self. i'll do what you suggest also. thank you. how do i get back with you?
HVAC Technician: Phil, Mechanical Engineer replied 10 months ago

Depending on the brand and model number of the water heater, you should not open it yourself... lets hold off on that for a while.

You get back to me the exact same way you posted your follow up note.

You can also bookmark this URL

http://professional.justanswer.com/chat/index/a996772e745b40c0841d0f552a05bf12

.

Just try opening two hot water taps and once and tell me if that seems to solve the problem... if it does then try opening just one tap but open it wider for more flow and tell me if it still cycles to HOT /COLD anymore.

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Customer reply replied 10 months ago
i turned both hot water taps on at once and that seemed to help.. is there a next step?
HVAC Technician: Phil, Mechanical Engineer replied 10 months ago

Thanks.

The situation is that there is a minimum water flow required through the water heater in order to keep it firing. If the water flow drops below that level it will stop firing .... "firing" means the water heater burner is running.

If you have a 'water saver' type shower head, that reduces the water flow, in order to save water, you will often not get enough flow to keep the water heater you have turned on.

The solution is to measure the hot water flow out of the fixture using a one gallon pot... it it takes much longer than 80 seconds to fill the pot, then replace the 'water saver' shower head.... if it fills the pot in less than 80 seconds, then you need to call a plumber and ask him to flush your water heater with white vinegar to get rid of the built up hard water scale. ... and.... if that fails, replace the flow switch in the water heater.

.

When you have all that you need, its time to locate the 'Finish and rate your expert..." link near the top of your page and click on it, that closes the question and gets me paid by the company. Thanks

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