How to tell if my geyser is on

[Solarphile 95]

I have a kwikot geyser that I run off my 6kw inverter which is downstairs in the garage. Being restricted to 6kw at a time I want know when the geyser is on without having to physically go downstairs to see on the inverter how many KW are being drawn. 

Is there a way to tell when the geyser is on and off via a light that I can hook up to the thermostat or element perhaps through a relay? The one option I had is to install one of these pictured below, but I want something cheap and simple... 

 

 

[Richard Mackay 118]

If you have this type of thermostat then you can use the contacts provided (the 2 brass sockets)

I can't recall if they are the same connected to the same contacts that switch the element. Check with a mulimeter..

 

[Vassen 216]

You could use some sort of power monitor and check the power utilization. I use the Ellie’s efergy and I can use the portal to see if the geyser is on or not. There’s others available now like the cbi astute or Shelly em 

[Solarphile 95]

Thank you for your replies guys. I like the idea of a small LED light connected to the back of the thermostat. It is simplistic and cheap.

[Solarphile 95]

Thank you for the advice Richard, I just finished the job now and it works perfectly. I just pulled the thermostat out a little bit, slid the bare wire of the twin flex into the two female lugs of the element and pressed the thermostat back in place. I ran the twin flex to a small LED light mounted to my ceiling. Now I can tell when the geyser is on or off.

[Richard Mackay 118]

Those sockets are a strange size (I think they have a dedicated plug assembly that plugs into it for many $$)

[Bobster 190]

This is a very neat hack (in the original sense of that word). 

[Solarphile 95]

1 hour ago, Richard Mackay said:

Those sockets are a strange size

My thermostat didn’t even have those brass holes (sockets) at the back, but pushing the wire into the back of the element worked perfectly. The thermostat went in a bit tighter than normal, but I didn’t have to force it. I am really chuffed with how simplistic it is and it only cost me an LED globe and a globe holder, I used twin flex that was left over from a previous project.

[Solarphile 95]

2 hours ago, Bobster said:

This is a very neat hack

I had to do something. I only have 6kw to play with, the geyser is 3kw and while it is on I am limited in what else I can do. If I want to wash and tumble dry I need to wait for the geyser to first switch off. To have to walk downstairs and check how much power the inverter is using is a chore. Now I can see straight away when it goes off. Also if Swambo forgets the geyser on, it will also serve as a reminder.

[Bobster 190]

On 2020/12/01 at 11:11 AM, Solaris said:

I had to do something. I only have 6kw to play with, the geyser is 3kw and while it is on I am limited in what else I can do. If I want to wash and tumble dry I need to wait for the geyser to first switch off. To have to walk downstairs and check how much power the inverter is using is a chore. Now I can see straight away when it goes off. Also if Swambo forgets the geyser on, it will also serve as a reminder.

I understand the need, I'm just applauding the elegance of the solution. It does exactly what is required with no bloat, and makes clever use of the existing hardware.

[Richard Mackay 118]

On 2020/12/01 at 11:11 AM, Solaris said:

I had to do something. I only have 6kw to play with, the geyser is 3kw and while it is on I am limited in what else I can do. If I want to wash and tumble dry I need to wait for the geyser to first switch off. To have to walk downstairs and check how much power the inverter is using is a chore. Now I can see straight away when it goes off. Also if Swambo forgets the geyser on, it will also serve as a reminder.

So are you managing the PV power manually? (Yelling instructions to the electricity users when they can or can't??) 

[Solarphile 95]

Well actually the idea came from what Richard said about the brass sockets at the back of the thermostat. However I reasoned that the light might then stay on permanently. The thermostat is a switch and I needed to get the wires behind the switch. Then after lots of thinking, I got the idea to push the bare wires into the female lugs of the element. I really wasn’t sure if it would work or not.. so I turned the geyser on and let it warm up. The whole time the light was on, I wasn’t sure if I had done it correctly. Only when the light turned off after an hour did I realise that the plan worked. 

I made a Macgyver
 

[Solarphile 95]

13 minutes ago, Richard Mackay said:

So are you managing the PV power manually? (Yelling instructions to the electricity users when they can or can't??) 

Exactly!

The whole automated thing seems a little too “finicky” to me. I don’t have much trust in electronics. Mechanical is my thing.  While others will disagree with me, I just feel safer with more simplistic mechanical devices. 

We stagger any heavy loads throughout the day and don’t run too many things at once. 

Swambo has a system where she has certain times to turn selected things on. The only thing that was a little tiresome for her was to have to walk downstairs to check if the geyser was hot or not. Now, thanks to your idea about the thermostat she is much happier.

 

[Bernardf 19]

I installed the Geyserwise TSE 6 months ago, and I am very happy with it. My reason for installing it was to run my geyser in the middle of the day when solar power is usually at a maximum. The reasons that I chose it over a basic timer is that you can put the control panel anywhere you want (whereas a basic timer is usually installed in the DB), you can adjust the temperature and have different temperature settings at different times of the day, and you can easily see whether the geyser is on and what the temperature is.

[Richard Mackay 118]

1 hour ago, Solaris said:

Exactly!

The whole automated thing seems a little too “finicky” to me. I don’t have much trust in electronics. Mechanical is my thing.  While others will disagree with me, I just feel safer with more simplistic mechanical devices.

I know the feeling. My mission has been to reduce the temperature of my geyser and only to switch it on when required for showers etc. This was to determine the minimum power that was needed for hot water. (I have no solar heating)

This has now been going on for a year with me switching the power on/off at the appropriate time of day. Being a control tech hasn't got me motivated to automate this process. Perhaps when I install my Geyserwise PV system I'll let it heat the water up to whatever temperature it can get to and I won't need to switch the geyser so often (and also not live in fear of forgetting to do this!)

[Solarphile 95]

I had one of these in my last house and it was fantastic. It has a rotating dial that has little grey tabs that you click to the left. Each tab represents 15 minutes. I used to be able to turn my geyser on for anything from 15 minutes upward. I used to have it on for 30 minutes in the morning and 1 hour 15 minutes in the afternoon. That was enough to have hot water all day long. 

 

 

 

[Richard Mackay 118]

19 hours ago, Solaris said:

I had one of these in my last house and it was fantastic. It has a rotating dial that has little grey tabs that you click to the left. Each tab represents 15 minutes. I used to be able to turn my geyser on for anything from 15 minutes upward. I used to have it on for 30 minutes in the morning and 1 hour 15 minutes in the afternoon. That was enough to have hot water all day long.

I'm sure this is the method most people use.

However it's not a smart control system. (e.g. what if there isn't enough PV power because it's overcast or Swambo is using the hair drier..)

Heating the geyser should happen only when there aren't other big loads drawing power. To do this the smart way you need to determine if there is available power. i.e. that when the geyser switches on it can handle it. This isn't easy but it is possible.. (this is my homework for the Xmas break)

[Solarphile 95]

3 hours ago, Richard Mackay said:

To do this the smart way you need to determine if there is available power. i.e. that when the geyser switches on it can handle

I get you. This would be an interesting and challenging project. Perhaps a series of relays. Some normally open, some normally closed. They would have to be cleverly set up that they will only allow power to certain plugs once the geyser turns off. 
 

I like this idea. This will be my next project..

[Bloubul7 71]

3 hours ago, Richard Mackay said:

I'm sure this is the method most people use.

However it's not a smart control system. (e.g. what if there isn't enough PV power because it's overcast or Swambo is using the hair drier..)

Heating the geyser should happen only when there aren't other big loads drawing power. To do this the smart way you need to determine if there is available power. i.e. that when the geyser switches on it can handle it. This isn't easy but it is possible.. (this is my homework for the Xmas break)

It is fairy easy to do if you have a home automation system.

Depending on your inverter model, you can setup communication from your Inverter to your Home automation.  I use PV Watts, Battery SoC and Battery Watts to control my pool pump.  If it is overcast then the pool pump doesn't run.  On sunny days the pump will run during the set time, if the battery SoC is full and there is still some PV Watts left then the pump will run until the system detects that it is starting to use battery power

Edited December 4, 2020 by Bloubul7

[Richard Mackay 118]

3 hours ago, Bloubul7 said:

It is fairy easy to do if you have a home automation system.

Depending on your inverter model, you can setup communication from your Inverter to your Home automation.  I use PV Watts, Battery SoC and Battery Watts to control my pool pump.  If it is overcast then the pool pump doesn't run.  On sunny days the pump will run during the set time, if the battery SoC is full and there is still some PV Watts left then the pump will run until the system detects that it is starting to use battery power

What Home automation software are you using and how are you communicating with your inverter?

[Bloubul7 71]

4 hours ago, Richard Mackay said:

What Home automation software are you using and how are you communicating with your inverter?

Home assistant

The inverter communicates through Modbus to MQTT

[Richard Mackay 118]

What variables are available in your inverter that you can access over this link? (Is there a document listing them)

[Riaan7806 1]

Seeing that I am in the automation business, and my whole house is already auomated. Lighting, geyser, pool pump, curtains, entertainment ect. It made sense to utilise it to space all the usage through scheduling and by measuring the load. I also replaced the 4kw geyser element with a 2kw, now I dont have a problem with overloading when the pool pump, geyser and other things are on during the day time. The geyser's smart thermostat which is programable on my phone allows me to see the curent temp. I have adusted the temp to 70deg, this way it has the whole day to get there ( usualy by 10am). It allows for 2-3 baths in the evening. 

I also have programed the system to monitor the grid supply, sending me notifications once it goes off and once it is restored. I have Alexa's in each room and it also anounce if the grid goes on or off. Once the grid fails the system imediatly turns of the geyser and pool pump, in an attemt to conserve energy. I might include some condition based on the available sun at some point.

I wanted to make sure that swambo does not get annoyed by giving het all the rules, what to turn on or off, and automating all of this has made it so smooth, all of this happens without us even thinking about it.

[Chris Hobson 1,781]

cheap and simple.... CT Ammeter.

 

 

[Solarphile 95]

4 hours ago, Chris Hobson said:

cheap and simple.... CT Ammeter.

Cheap and simple.... lightbulb

Geyser on = light on.

Geyser off = light off.

 

 

 

 

[Gerrie 113]

39 minutes ago, Solaris said:

Cheap and simple.... lightbulb

Geyser on = light on.

Geyser off = light off.

This would be easy to install on the old type geyser thermostats where a piece of wire and screwdriver would do the trick, but the new thermostats plug in with male pin lugs into the elements female plugs. Some intervention would be needed to tap-into those female element terminals. Everyting these days are made more complicated and less handyman friendly.