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.

WildWater

https://www.boards.ie/discussion/comment/120921691#Comment_120921691

I had the same problem of Eddi displaying Max Temp Reached even though the water was cold. This seems to have got me sorted...

https://youtu.be/OCD-0yo80lk

ollin

Thanks for your reply, I tried that today. Seems no better, max temp reached way too quick again. I might just bite the bullet and replace it, although a week prior to solar install I had a spark out to check it out and he said everything looked 100% with immersion. Things never seem to be straightforward in my house but once we get to the bottom of it I'll post back to let yee know.

tandcapply

Got relay board and pt1000 self installed today.

Trying to figure out where is it best to attach to as it currently early evening) shows 26degrees Celsius when just (temporarily) sits near the lower thermostat. And 34deg when was near the pipe above where it shows below

UPDATE: sunny day today, lunchtime.

Max temperature reached came up after 1.6kwh drawn. Probe near upper pipe on the left showed 44deg and when moved lower (as per photo above) showed 34deg.

Is it likely that only the short element (of the dual) is heated by eddi?

Also, Ive just limited eddi to 4A (1kw) under device limit..

Nelbert

Seems likely that the Eddi is on the small element, top is heating and not circulating.

The limit is a stop gap to getting the eddi hooked in to the bath element and your temp probe in a suitable place. The Eddi has a cut off heat setting so best to set that below the cut off of the immersion heater tripping point.

graememk

https://www.boards.ie/discussion/comment/120962641#Comment_120962641

If you remove the device limit and boost the eddi manually, what power does it use for each tank? I am looking for power, kW not energy kWh.

If it's about 2kw it's on the sink, 3kw it's on the bath.

tandcapply

https://www.boards.ie/discussion/comment/120971625#Comment_120971625

Increased the top Thermostat on the cylinder to about 80deg as a test.Tank2 drew 2.5kwh today and pt-1000 Probe placed at 1/3 down from top showed 50deg and had plenty of water but definitely not leaving the thermostat at 75-80 degrees

Nelbert

To clarify drew 2.5kW or 2.5kWh?

tandcapply

https://www.boards.ie/discussion/comment/120973494#Comment_120973494

I meant 2.5 kWh (corrected above too)

Nelbert

So you got it to take more energy overall by limiting it to approx 1kW draw at a time.....

That's good. The next step would be to turn the limit off, manual boost and see the max instantaneous draw as someone mentioned earlier - 3kW means bath element, 2kW or less and it's likely connected to the sink element.

If you confirm that it's the sink element you can either connect the bath too and reconfigure the Eddi accordingly or swap it to just hook up to the bath element.

tandcapply

@Nelbert sorry for late reply. It drew 2.4kw in bypass mode. Not sure if it helps determine long or short element.

Nelbert

https://www.boards.ie/discussion/comment/121002590#Comment_121002590

Depends on the exact model but it's most likely connected to the shorter element (would expect long one to pull ~3kW). So it's heating the top part of your tank and triggering the temp cutoff too early as the water isn't circulating....

Quick solution is to knock everything off at your consumer board and swap it to the other element and then retest again with no current limit. If that pulls ~3kW you then have it connected to the long element and it's likely to be able to heat up find without a current limit imposed.

Edit: that assumes you're comfortable! If not get a sparks!

graememk

https://www.boards.ie/discussion/comment/121002860#Comment_121002860

Or try boosting the other "tank" and see if that is connected.

tandcapply

It drew 2.4kw in one go.

Not sure if that solves it

graememk

https://www.boards.ie/discussion/comment/121010024#Comment_121010024

Both draw 2.4kw?

tandcapply

https://www.boards.ie/discussion/comment/121010106#Comment_121010106

Only tried tank2. Tank 1 only every got to 1.3kWH (and never switched to tank2 as showed max temp reached) so pretty much left it alone, assuming it's the short element so lesser priority and trying to get tank2 to get as close to 3kWH without turining up the Thermostat to 85Degrees celcius

slave1

Nothing wrong with turning up the temp to 85degrees as long as you don't continually trip the internal cut-off, just throw a mixer value on the output to avoid gross 85degrees hitting the taps etc

Jonathan

https://www.boards.ie/discussion/comment/121011025#Comment_121011025

Lots of shower pumps aren't rated for that temperature so you need to be careful.

tandcapply

https://www.boards.ie/discussion/comment/121011025#Comment_121011025

I'm also reluctant to go higher than the current 70ish degrees the cylinder thermostat is sets to as the mixer tap can scald if someone moves the lever to the most left position

Nelbert

https://www.boards.ie/discussion/comment/121010946#Comment_121010946

You're bouncing between kW and kWh so it's hard to be sure what you mean at times...

kW is instantaneous power - i.e. it's pulling 3kW (e.g. 240V x 12A).

kWh is total energy. So if your 3kW immersion was on full blast for an hour it would use 3kWh.

Without any limits in place you need to establish which element is able to pull the higher instantaneous power as that will be the longer "bath" element and will enable getting the most overall energy in to the tank.

slave1

https://www.boards.ie/discussion/comment/121013580#Comment_121013580

My pump is 65max which is the reason for mixer which lowers temp to 60 by mixing in from the cold tank as necessary