stiebel eltron water warmer, power light switches off when water is hot, then on again ?

rech · February 18, 2020

hello,

do you know if it's standard for a stiebel eltron water warmer ? the power light switches off when water is hot, then it switches on again few second later when water starts to be cooler.

the problem is that when light is on water can be too hot and we need to mix it with cold water, but then when the light is off, we need to only turn on hot water (no cold water) until the water is hot enough, and then start again...

It does not seem correct ! it's only a 3500w heater. What do you think ?

Shouldn't these heaters always heat the water when using hot water ?

Also, i noticed that now the new stiebel etron warmer has a plastic reservoir when it was copper made in the past, could it be related ? maybe plastic reservoir cannot stand too hot water too long time ?

thank you for your ideas.

Crossy · February 18, 2020

Which model heater do you have?

I suspect not enough water flow, check your shower head, feed tubes and the gauze filter on the heater inlet.

Do you have a water pump?

rech · February 18, 2020

4 hours ago, Crossy said:

Which model heater do you have?

I suspect not enough water flow, check your shower head, feed tubes and the gauze filter on the heater inlet.

Do you have a water pump?

Thank you !

no water pump, it's a condo, and the previous stiebel light did not switch off and on as i remember.

its a basic 3500 watt stiebel.

So you think that light should not turn off and it should be on all the time ?

Crossy · February 18, 2020

10 hours ago, rech said:

So you think that light should not turn off and it should be on all the time ?

From what you are describing it's the overheat protection triggering, it should be on all the time if you have a decent flow rate.

The reason I asked for the model number is that you mention a mixer tap. Is the unit a multipoint heater intended to feed a mixer or a simple shower heater just intended for a shower head?

rech · February 19, 2020

4 hours ago, Crossy said:

From what you are describing it's the overheat protection triggering, it should be on all the time if you have a decent flow rate.

The reason I asked for the model number is that you mention a mixer tap. Is the unit a multipoint heater intended to feed a mixer or a simple shower heater just intended for a shower head?

The model is STIEBEL ELTRON AQ35E-3 (3500W)

https://www.lazada.co.th/products/stiebel-eltron-aq35e-3-3500w-i296056251-s502308129.html

The unit is connected to a mixer but even if I turn only to the left for only hot water, the power light turns off when water is already hot.

The previous stiebel was connected to the same mixer and was working perfectly, so I am wondering if the new one could have something wrong ?

thanks again.

bankruatsteve · February 19, 2020

Post a photo. The unit is "stand alone" = cold water in, hot (warm, whatever) out. What "mixer" is it connected to?

Crossy · February 19, 2020

How's the flow rate?

How about if you dial down the heat control?

That unit doesn't appear to be a multipoint, so it's not really intended to drive via a mixer. Can you hook the shower directly to the outlet? Does it work any better?

eyecatcher · February 19, 2020

Almost certainly due to the flow rate and the reasons most oftem to be the culprit are that your tap or mixer is not fully open, the blue/red incoming service valve tap is not fully open or that you have some fine grit and deposits caught up in the filter.

if your taps are not open then it means you need to disconnect the electric and remove the cover to get to tge filter

Moonlover · February 19, 2020

@Crossy is correct. That is shower unit and should not be connected to a mixer unit. In fact it is very important that the output goes directly to the shower head with no intervening valve. That will be clearly stated in the installation instructions if you still have them.

@eyecatcher mentioned the filter. You do not need to remove the cover to access this filter. You just need to remove the inlet pipe. You can actually see it in the Lazada photo of the bottom of the unit.

eyecatcher · February 19, 2020

2 hours ago, Moonlover said:

@Crossy is correct. That is shower unit and should not be connected to a mixer unit. In fact it is very important that the output goes directly to the shower head with no intervening valve. That will be clearly stated in the installation instructions if you still have them.

@eyecatcher mentioned the filter. You do not need to remove the cover to access this filter. You just need to remove the inlet pipe. You can actually see it in the Lazada photo of the bottom of the unit.

Ah ok, I have the stiebel multipoint and the filter basket is a real pita to access requiring removal of the copper pipes to the heat exchanger

rech · February 26, 2020

Thank you to all and sorry for delayed reply.

The problem was the shower head !

Weird that it was ok with exactly the same former water heater, but with the new one, I had to change the shower head and then the power light did not switch off anymore.

I guess that as you said, there was not enough water flow and it was switching off to avoid overheating.

Anyway, Stiebel are idiot cheaters who put plastic reservoir where 5 years ago it was copper.

Or do you think that plastic is perfectly acceptable for a part that keeps hot water ?

Thanks again.

Moonlover · February 26, 2020

2 hours ago, rech said:

Thank you to all and sorry for delayed reply.

The problem was the shower head !

Weird that it was ok with exactly the same former water heater, but with the new one, I had to change the shower head and then the power light did not switch off anymore.

I guess that as you said, there was not enough water flow and it was switching off to avoid overheating.

Anyway, Stiebel are idiot cheaters who put plastic reservoir where 5 years ago it was copper.

Or do you think that plastic is perfectly acceptable for a part that keeps hot water ?

Thanks again.

Glad to hear that that you have resolved your issue. Great what a bit of teamwork can do.

I wouldn't be too alarmed about the plastic tank. STIEBEL ELTRON is German as I'm sure you know and like most German companies, will take the quality and reliability of their products seriously.

Anyway hope you have many happy showers.

longball53098 · February 27, 2020

19 hours ago, rech said:

Thank you to all and sorry for delayed reply.

The problem was the shower head !

Weird that it was ok with exactly the same former water heater, but with the new one, I had to change the shower head and then the power light did not switch off anymore.

I guess that as you said, there was not enough water flow and it was switching off to avoid overheating.

Anyway, Stiebel are idiot cheaters who put plastic reservoir where 5 years ago it was copper.

Or do you think that plastic is perfectly acceptable for a part that keeps hot water ?

Thanks again.

I think if you research the use of what you call "plastic" for the tank is actually a very special composite material made for this use and you can be sure Steible knows exactly what they are doing in using this type of tank

essox essox · February 27, 2020

On 2/18/2020 at 6:56 PM, rech said:

Thank you !

no water pump, it's a condo, and the previous stiebel light did not switch off and on as i remember.

its a basic 3500 watt stiebel.

So you think that light should not turn off and it should be on all the time ?

mine stays on all the time when hot water is coming out....

rech · April 2, 2020

On 2/27/2020 at 8:26 AM, longball53098 said:

I think if you research the use of what you call "plastic" for the tank is actually a very special composite material made for this use and you can be sure Steible knows exactly what they are doing in using this type of tank

yes for sure ! and they are not using it because it's cheaper...

how gullible are people is so weird !

kamalabob2 · April 2, 2020

I currently own and use six Stiebel Eltron multi point water heaters in a home I built in 2008. Three are new water heater units and three are original installations. I have experienced no difference between the 2008 copper tanks and the 2018 composite material tanks. The water pressure in that home is provided by a Mitsubishi Super Pump. I do own a "on the wall" Stiebel Eltron 4500 watt water heater in a compact village home. It works fine especially after I clean the shower heads. I can state from personal experience that Stiebel Eltron and Panasonic provide excellent warranty service for hot water heaters in Buriram.

https://www.buriramhome.com/buriram-guest-bedroom-suite/

https://www.buriramhome.com/buriram-architect-house-floor-plans/