No tank temperature showing on eddi (new install) and max temp reached too quickly

tandcapply

Current hot tank – copper, 12 years old.

Eddi showing 1 CT (Grid) have no Zappi or Harvi (still unsure if I should get one and if I’m missing out on some stats without it.

I’ve Googled PT1000 but not sure if it’s needed for seeing temperature in MyEnergi and if a new, bigger, modern Cylinder will have something built in

 

Also, I can see 2 tanks in MyEnergi, not sure if it’s two elements as I’ve a gas boiler and immersion (never used before) or just a redundant line in the App

I tried to switch priority between both tanks options yesterday and today, seems to me that with either priority, one will heat a bit and wil lreach max (also no heating 2nd one if even exists) so that I’ll have some hot water for about 5 minutes and then it’s cold again.

tandcapply

Gas or boost weren't turned on yesterday so meant to be from cold.

MyEnergi -> Eddi screenshot:

THE ALM

You will need the relay board addon and a PT1000 for the temperature.

Do you have a CT fitted for the grid?

Do you have two elements on the the immersion, generally sink or bath, are both wired in the Eddi?

Max Temp Reached generally means the the immersion thermostat will need to be reset, a small button on top of the immersion.

bullit_dodger

Could be that the person who installed it only wired it up to the "sink" element.

@graememk had a neat trick for this. When you turn on the "boost", what power draw does the Eddi sent to the elements? If it's 2.0kw then only the SINK is active, and if it's 2.8Kw then the BATH element is in operation. Naturally you want the BATH element to work as otherwise your only heating the top of the tank.

if it's the SINK onlythat's working, you should be able to fix that. Disabling the circuit (important) remove the cover and check the situation of what wires are hooked up. It could simply be a case of moving the wires to the other element. Also, there usually is a thermostat there, check that it's 60C.

If your not comfortable with electrics (wiring a plug level), then I'd advise to get someone who is or a spark.

tandcapply

Seems to have drawn 2.3 today.

Reset worked

tandcapply

Spoke too soon, reset allowed Eddi to send more to immersion but shower was warm for a few minutes only.

2.3Kw sent to Eddi today

bullit_dodger

https://www.boards.ie/discussion/comment/120736748#Comment_120736748

Just to be clear, your saying "2.3kwH" was sent to the Eddi today? "2.3Kw" is an instantaneous power draw while 2.3KwH is the amount of power consumed over time. units matter as without units we could be trying to solve the wrong problem.

How big is your tank? 125liters? 200 Liters? You should be able to work out (roughly) from the capacity of the tank the amount of water your heating if 2.3KwH was the amount in total sent to the immersion. If you tank is (say) 100Liters and you have a power shower, your not going to get much more than 5-6 mintues at 12-15liters a minute before the water goes.

tandcapply

Sorry, meant 2.4 kwh as of now.

Tank is a copper 95l. About 12years old.

When heating same tank using gas, we get about 20 minutes worth of hot water so assumed similar with eddi.

Nelbert

If the temp cutoff has kicked in but the shower runs out of water sooner than heating with gas there's things to consider.....

1. Gas doesn't use the immersion so heats the whole tank.

2. The sink element may be connected to the Eddi and heat the top of the tank enough to trip the cut-off but actually that's just the top of the tank.

A thermostat probe for the tank and making sure the Eddi is connected to the bath element would be a priority.

bullit_dodger

You can sort of "reverse engineer" from your data how much water you heated.

Water Heating Calculator (omnicalculator.com)

Using a starting value of 20C and an end value of 60C (most immersions are set to cutoff at 60C) and then keep changing the "mass of water" until you get close to your 2.4KwH, you can see that you heated about

So you heated about 50 liters. If you have a pumped shower, they knock out about 10-15 liters/min. Granted not all of that is hot water at 60C, so it's probably a 50-50 mix of hot and cold. So you were using 6-7 liters of hot water a min. Wouldn't expect to get much more than 5-6 mins of good hot water out of that tank. Did you look at what the thermostat is set to (similar to my picture above) - don't forget to turn it off before opening, naturally.

You could up that to 65C that could give you more "thermal mass" and effectively more hot water, although you should be careful then that people realize that 65C could be in the kitchen sink. Fine if it's only adults in the house, but I'd be hesitant to do it if there were kids present in the house for risk of scalding

tandcapply

https://www.boards.ie/discussion/comment/120736998#Comment_120736998

Still at it, seems like I'm only getting around 33-35litre heated:

denismc

It does sound like you are only heating the top portion of the tank, I have similar set up to yours and it takes 3.5-4.5kWh to get a full tank at 65 degrees.

From your second photo it looks like you have set the smaller element to heat first, have you tried switching the priority in the app so that "Hot water element !" heats first.

Your original "immersion" probably has 2 heating elements (sink & tap) but only has a single thermostat so that when the smaller element reaches 65 degrees it just stops heating, if you want the eddi to switch between heating elements you would need a relay board and a PT 100 temperature sensor to read the temperature.

I hope this makes sense.

tandcapply

https://www.boards.ie/discussion/comment/120889290#Comment_120889290

@denismc The long element is set up as priority. And today again, 1.4KWH from pretty cold tank to max tem reached after usage yesterday.

The thermostat seems to be below the short element

I'm nearly sure that this is the dual element I have, so the thermostat is located much lower than the short element:

denismc

The eddi has a boost function which heats the water regardless of your solar output, have you tried this?

graememk

https://www.boards.ie/discussion/comment/120889525#Comment_120889525

Thermostat is higher than both immersions and is shared, it cuts off both immersions

Immersion may not be that long.

tandcapply

https://www.boards.ie/discussion/comment/120889580#Comment_120889580

I tried bypass mode for circa 1h and it did nothing

@graememk It's 27" so assume reaches nearly all the way to the bottom of the tank which is 30" in height.

Btw, took a photo of the Thermostat on the immersion (can't see numbers so unsure what temp is it set to):

denismc

It maybe that the actual heating element itself is breaking down, you would need a plumber or electrician with a multimeter to check this, it shouldn't be a big job to replace.

tandcapply

Spoke to a DIY Plumber acquaintance who recommended increasing the red (1/8 turn) immersion thermostat to circa 70-75degrees as a test first to see if more power i drawn.

I told him that if I switch the old immersion switch from sink to bath and/or the immersion switch from on to off it cuts power to the Eddi (assuming both are part of the wiring of eddi).

He said that since we've mixer taps, the risk of scalding is lower, not eliminated of course.

We know that we'll need to keep an eye on taps and test output temps on taps if leaving it at 70+ degrees.

Eddi had drawn 2.3kWh today in one go from cold before reaching max temperature reached with the above setting.

any drawbacks to leaving the red immersion thermostat turned to that higher setting?

graememk

https://www.boards.ie/discussion/comment/120892974#Comment_120892974

As a sanity check, when the tank is cold how much power is drawn by each element when you" boost " the immersion on the eddi

Turning the thermostat up will just make your water hotter, if it's too high the immersion may trip out and you will need to press the reset button on it.

Hellrazer

Eddi and immersions - always loads of questions. Usually the problem is either the electrician has wired up the wrong element, element too short or the temperature is being reached too quickly - "max temp reached" in the eddi app - it doesnt mean the immersion has tripped.It means the water has reached the thermostat limit on the immersion.

The only sure fire fixs are a stratification pump to circulate the water. Or new tank with a single element mounted right at the bottom of the tank.But best to do both.

tandcapply

Cheers, I'm at a bit of a dilemma.

Trying to see where the problem is and getting it sorted so that I can see if the existing Cylinder is large enough or if we need to go bigger.

Thus far, getting very little out of eddi so not even sure if worth all the hassle and money for yet unknown x days of solar generated hot water per year

John.G

The thermostat (should) switches the neutral so doesn't matter which element is in use from a control point of view. Your 95L cylinder with a 27" bath element in a 30" high cylinder will absorb 4.47kwh in heating 85.5L from 15C to 60C which will provide 154L of hot water at 40C, if its heated to 70C then 5.47kwh absorbed which will provide 188L of hot water at 40C. This assumes the 27" (bath) element is being used.

tandcapply

Cheers, best I got thus far is 2.3kWh yesterday when thermostats set to 75

tnegun

Try limiting the output of the eddi so that the element heats the water more slowly giving time for some mixing/convection in the tank to take place. Look for Grid Limit under Advanced Settings. Setting it to 6A would be a good start and experiment from there. The trade-off is that it will take longer to heat the tank and you'll need excess available for longer but you might find a happy medium and heat slightly more water.

tandcapply

https://www.boards.ie/discussion/comment/120892992#Comment_120892992

@graememk It's been crap weather here today so can't test again today (only got 0.6kwh and no sun at all), but yesterday I got 2.3kwh from cold.

It never goes to the other element. If I choose tank1 as priority I was getting 1.3kwh and if I prioritise tank2 I got 2.3kwh as per above.

Not sure if there's a setting that I'm missing or the installer have missed

graememk

https://www.boards.ie/discussion/comment/120899427#Comment_120899427

I was talking about instantaneous power ie kW, tank 1 is likely 2ish kw and tank 2 is 3 kw, (under boost not normal divert).

But Id say thats what the limit of your tank is before getting a destrat pump / longer immersion. But longer immersions can interfere with the Heating coils in the tank.

On the flip side, are you finding your running out of hot water?

tandcapply

https://www.boards.ie/discussion/comment/120899528#Comment_120899528

Yesterday we managed a quick shower and a small bath so making progress (assuming we leave the thermostats at 75degrees).

I'm starting to think that we won't achieve the holy grail of 3kwh (as per the label on the immersion) so won't be able to test it for say, two long showers before deciding what to do with the existing 95l tank

DC999

https://www.boards.ie/discussion/comment/120899596#Comment_120899596

How did it all work before the Eddi went in? As in did ye run out of hot water like ye are now? If ye did, then maybe the Eddi is fine. Pumped showers use way more water than electric showers.

tandcapply

https://www.boards.ie/discussion/comment/120904754#Comment_120904754

I've never used the immersion.

Used gas boiler.

System installed 10 years ago

con747

https://www.boards.ie/discussion/comment/120899596#Comment_120899596

A pumped shower will use about 10-15 litres a minute so a 95 litre tank won't be much use if you want a couple of long showers, if you can fit a bigger tank it's the way to go IMO.

ollin

Interesting reading this as I'm in the same predicament. Max temp reached on Eddi but water is only luke warm. My tank is a Grant DuoWave Plus 300 litre with immersion half way up. Solar PV 6.72 kwp system only installed since last Thursday. Hardly ever used immersion in the 7 years its in as we generally boost water through oil boiler. Spoke to installers who put it down to faulty immersion and suggested replacing it. If you come to any solution in the meantime please let us know.