Stiebel Eltron DHC 10-2 Electric Tankless Water Heater Logo

Related Topics:

Posted on Dec 14, 2017

Hi, I just got my new DHC 10-2 today, the installation was easy but I have a problem. The problem is that heating is not constant. Once I mix the cold and hot water I should have an uniform temperature but that is not happening. The water becomes very hot and then, it becomes cold again. It is a cycle. Help please.

1 Answer

rayc588

Level 1:

An expert who has achieved level 1.

MVP:

An expert that got 5 achievements.

Cheetah:

An expert who has answered 20 or more questions within one hour.

Hot-Shot:

An expert who has answered 20 questions.

  • Contributor 40 Answers
  • Posted on Dec 31, 2017
rayc588
Contributor
Level 1:

An expert who has achieved level 1.

MVP:

An expert that got 5 achievements.

Cheetah:

An expert who has answered 20 or more questions within one hour.

Hot-Shot:

An expert who has answered 20 questions.

Joined: Mar 31, 2009
Answers
40
Questions
1
Helped
16780
Points
65

This electric demand water heaters has one heater element. The flow switch turns it on. The thermostat cycles it on and off according to temperature. There is no medium.
You need to run the sink on hot while you take a shower. This kind of cancels out the savings on electricity.
Or get a higher flow shower head. Your screen on the shower head may be partially fouled.
Here is the brochure. It shows the flow rates for the different models.
http://www.stiebel-eltron-usa.com/sites/default/files/pdf/brochure-dhc.pdf

2 Related Answers

A

Anonymous

  • Posted on Oct 31, 2010

SOURCE: The water heater "Stiebel Eltron

I am a free answerer, and I specialize in giving you resources for free
The paid answerers may have a person who knows your product and the problems associated with your model.
I believe they offer a refund if the 'fix' doesn't work.
The manual might also have troubleshooting.

Each day I see 20-25 unanswered questions about tankless water heaters.
And the day before, there were same number of unanswered questions about tankless products.
The number of questions shows the complexity of the machines, the brand-specific-ness of the problems, and the inability of the manufactures to take care of their customers.
If I understand correctly, the manufacturer will refer you to the installer.
There are not many ways a do-it-yourself-er can fix a tankless.

http://www.thetankatwaterheaterrescue.com/forums/forum3/

Ad
kel1guy2002

Kelly

  • 3740 Answers
  • Posted on Apr 10, 2011

SOURCE: I installed a dhc tankless heater, but when I open

Hi and welcome to FixYa, I am Kelly.

What is happening is that your cold water flow is greater in volume (gals per min) than your hot water. So when you open the cold water it is mixing with the hot water inside the faucett or shower plumbing and actually reverse flowing back into the hot water heater plumbing. The reverse flow slows the water flow sensing turbine inside the heater and it is thinking that there is not any water flow. (There isn't actually due to the equalization of water pressure when you open the cold water faucett) Since this is a safety feature of the tankless heater to keep it from overheating, it shuts off.
Somewhere in the hot water plumbing there is a major restriction. It may very well be the internal plumbing of the tankless hot water heater or the flow detector design.

There are 2 ways to correct this. The easy way would be to restrict the available cold water flow. You can do this by installing another shut off valve inline with the cold water plumbing and just not open the valve all the way. You would have to adjust the setting so that the hot and cold water can be on at the same time and the hot water heater stays on. The hard way is to locate the hot water flow restriction and eliminate it.
It is possible.... if you have a flow restrictor in a shower head or a screen in a faucett areator that they are partially clogged. Clean any flow restrictors and screens then see how the hot water heater performs before you start modifying plumbing.

Thanks for choosing FixYa,
Kelly

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

Why newly installed DHC 8 water heater not heating water.

hi, if this is a major domestic appliance installation issue you might be best served by getting a professional / qualified technician to look at it. There are safety concerns where such installations are involved. Investigating yourself might, in any case, invalidate any warranty you might have on the hardware concerned.
Good luck with this Brian
0helpful
1answer

How do i fix my stiebel eltron tankless electric water heater?It stop working..

Th easy fix would be installing a new heating element that has burned out. You don't say what size this tankless heater but if it stopped working entirely you might have just one heating element inside. You can test it by (1) turning off the circuit serving the heater, disconnecting one of the wires to the heating element, then taking an ohmmeter to see what the resistance of the element is. If it is "infinity" then it is open and burned out. Replace element. If it is around 6 ohms (for a 10kW heater running at 240V) then the heating element is OK. Unfortunately those heating elements don't last forever. Check the repair manual on how to replace the heating element.
0helpful
1answer

Unit cuts off after 3 mins of heating water

Sounds like the heating element in the unit is shorting out. If you are handy you may be able to replace the part but I would recommend having someone look at it who is familiar with this unit.
0helpful
1answer

My tankless water heater is not very old, but I have to depress the relay to make it heat water. It will depress on its own sometimes, then other times not at all. How do I adjust this?

Hi,
There is no adjustment for that... the thermostat is not telling the relay to pull in all of the time. I would replace the thermostat, I think you will find that it is your problem...

heatman101
0helpful
1answer

I installed a dhc tankless heater, but when I open only the hot water everything is ok, but when I open the cold water at the same time the heater turns off.

Hi and welcome to FixYa, I am Kelly.

What is happening is that your cold water flow is greater in volume (gals per min) than your hot water. So when you open the cold water it is mixing with the hot water inside the faucett or shower plumbing and actually reverse flowing back into the hot water heater plumbing. The reverse flow slows the water flow sensing turbine inside the heater and it is thinking that there is not any water flow. (There isn't actually due to the equalization of water pressure when you open the cold water faucett) Since this is a safety feature of the tankless heater to keep it from overheating, it shuts off.
Somewhere in the hot water plumbing there is a major restriction. It may very well be the internal plumbing of the tankless hot water heater or the flow detector design.

There are 2 ways to correct this. The easy way would be to restrict the available cold water flow. You can do this by installing another shut off valve inline with the cold water plumbing and just not open the valve all the way. You would have to adjust the setting so that the hot and cold water can be on at the same time and the hot water heater stays on. The hard way is to locate the hot water flow restriction and eliminate it.
It is possible.... if you have a flow restrictor in a shower head or a screen in a faucett areator that they are partially clogged. Clean any flow restrictors and screens then see how the hot water heater performs before you start modifying plumbing.

Thanks for choosing FixYa,
Kelly
0helpful
1answer

No hot water!! For some reason it is not heating the water!?

is the heating element still good. Was it on when no water was running thru it?
0helpful
1answer

Blinking light on unit +shuts off completly for heating garage floor

I'm dealing with the same issue and the impeller on the flow sensor had broken off inside the sensor so the unit doesn't think it's getting the water flow it needs. Fix is replace flow sensor
0helpful
1answer

The water heater "Stiebel Eltron

I am a free answerer, and I specialize in giving you resources for free
The paid answerers may have a person who knows your product and the problems associated with your model.
I believe they offer a refund if the 'fix' doesn't work.
The manual might also have troubleshooting.

Each day I see 20-25 unanswered questions about tankless water heaters.
And the day before, there were same number of unanswered questions about tankless products.
The number of questions shows the complexity of the machines, the brand-specific-ness of the problems, and the inability of the manufactures to take care of their customers.
If I understand correctly, the manufacturer will refer you to the installer.
There are not many ways a do-it-yourself-er can fix a tankless.

http://www.thetankatwaterheaterrescue.com/forums/forum3/
Not finding what you are looking for?

458 views

Ask a Question

Usually answered in minutes!

Top Stiebel Eltron Water Heaters Experts

littlewheel

Level 2 Expert

122 Answers

Brad Brown

Level 3 Expert

19187 Answers

ADMIN Andrew
ADMIN Andrew

Level 3 Expert

66915 Answers

Are you a Stiebel Eltron Water Heater Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...