geyserwise & solar

spiff

spiff

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I'm out of my depth here hence the question regarding the setup of the geyserwise unit with a solar panel.

how do you ensure the AC heater element only comes on IF the solar temp drops below a certain temperature?
 
That's what the geyserwise does. It's a simple setting.

Note, the geyserwise will set the AC element on based on the geyser temp at a given time, not the solar temp.
 
Speedster said:
That's what the geyserwise does. It's a simple setting.

Note, the geyserwise will set the AC element on based on the geyser temp at a given time, not the solar temp.
Click to expand...
if there is two right ? solar and a electric geyser?
 
spiff said:
I'm out of my depth here hence the question regarding the setup of the geyserwise unit with a solar panel.

how do you ensure the AC heater element only comes on IF the solar temp drops below a certain temperature?
Click to expand...
What sort of setup do u have ?
I only have a solar geyser which has a built in electric heating element. The geyserwise controls the electric part and uses electricity if the temp falls below a set temp in a specific time interval.
 
spiff said:
so is that's why it has a recirculating pump?
Click to expand...
Uhm no, the circulating pump is needed for the solar to work. I think a short explanation might help...

You have panels or tubes on the roof which absorb heat from the sun and a container (aka geyser) that stores the water. The pump circulates the water from the geyser through the solar panel / collector where heat transfer takes place. This happens continuously throughout the day, as long as the panels are sufficiently warmer than the water in the geyser. The geyserwise then has the ability to turn on the AC element during a given period should the water not be warm enough as yet.
 
joker08 said:
What sort of setup do u have ?
I only have a solar geyser which has a built in electric heating element. The geyserwise controls the electric part and uses electricity if the temp falls below a set temp in a specific time interval.
Click to expand...
it's my GF setup.

she has a solar water heater feeding an electric geyser run by the geyserwise with a recirculating pump

she wants to be sure the electric element is not been used when the solar temp is higher than a preset temp.

So if I set ALL temps to 50 degrees then if the solar is hotter than 50 degrees - no power is used by the element
 
Speedster said:
Uhm no, the circulating pump is needed for the solar to work. I think a short explanation might help...

You have panels or tubes on the roof which absorb heat from the sun and a container (aka geyser) that stores the water. The pump circulates the water from the geyser through the solar panel / collector where heat transfer takes place. This happens continuously throughout the day, as long as the panels are sufficiently warmer than the water in the geyser. The geyserwise then has the ability to turn on the AC element during a given period should the water not be warm enough as yet.
Click to expand...
ok so it's like my SG / GG setup then.
hot water above 60 - no GG / water below 60 - GG kicks in

how much power does the recirculating pump use?
 
spiff said:
it's my GF setup.

she has a solar water heater feeding an electric geyser run by the geyserwise with a recirculating pump

she wants to be sure the electric element is not been used when the solar temp is higher than a preset temp.

So if I set ALL temps to 50 degrees then if the solar is hotter than 50 degrees - no power is used by the element
Click to expand...
Correct. The geyserwise has 4 time slots for temperature, 1) midnight to 6AM, 2) 6AM to noon, 3) noon to 6pm and 4) 6pm to midnight. The 4 temperature selections apply to these time slots.

And then you can select when, or if, to turn the element on at all. If she selects no on times for the element it won't ever turn on, irrespective of the temp settings. And then she can also set it in holiday mode in which case the element won't ever turn on either.
 
spiff said:
so there's no direct control of the pump then - it just run by itself even through the night time?
Click to expand...
Why would you want to turn the pump off? It'll only run at night if for some reason the panels are still warmer than the water, or if the panels are near freezing it pumps warm water through to protect the panels.
 
Speedster said:
Why would you want to turn the pump off? It'll only run at night if for some reason the panels are still warmer than the water, or if the panels are near freezing it pumps warm water through to protect the panels.
Click to expand...
Not going to turn off pump, it's in a complex so there nothing I can change other than the times, basically just want to understand the way it works.
 
spiff said:
so there's no direct control of the pump then - it just run by itself even through the night time?
Click to expand...
The pump turns on if the temp in the tubes is ~7C warmer than the sensor in the geyser

There is also a holiday setting that reverses this rule at night to try cool the geyser so it doesn't boil when its summer and no one is home to use the hot water

Regarding the mains element I have set mine to power on every day at 15:00 however the thermostat has to register a temp lower than 55C before the element is turned on. This way you are pretty much guaranteed hot water at night while maximising electricity savings
 
Tim_vb said:
The pump turns on if the temp in the tubes is ~7C warmer than the sensor in the geyser

There is also a holiday setting that reverses this rule at night to try cool the geyser so it doesn't boil when its summer and no one is home to use the hot water

Regarding the mains element I have set mine to power on every day at 15:00 however the thermostat has to register a temp lower than 55C before the element is turned on. This way you are pretty much guaranteed hot water at night while maximising electricity savings
Click to expand...
Apologies for resurrecting an old thread, but this post pretty much related to a question I have.

The 7°C you refer to, is the solar temperature differential. If the evacuated tubes (collector) have a temperature of 7° higher than the geyser temperature, the pump circulates the warmer water into the geyser.

My question is, what is the implication of adjusting this to 15°C? I'm thinking the water in the collector is much warmer than the geyser, and will heat up quicker. The drawback being it might kick in later in the morning and cut out earlier in the evening. I don't see it as a problem though because the tubes are very effective at heating.

When on 7°, the pump might cycle quite a bit and increase wear.

What is the benefit of keeping it at 7, 10, or even 15, and what is your preferred setting (if you have the Geyserwise Max)?

I'm very impressed with how well this works, my geyser has been on holiday mode for more than a week already.

IMG_20250204_175250~2.jpg
 
Last edited:
Stephan Maritz said:
Apologies for resurrecting an old thread, but this post pretty much related to a question I have.

The 7°C you refer to, is the solar temperature differential. If the evacuated tubes (collector) have a temperature of 7° higher than the geyser temperature, the pump circulates the warmer water into the geyser.

My question is, what is the implication of adjusting this to 15°C? I'm thinking the water in the collector is much warmer than the geyser, and will heat up quicker. The drawback being it might kick in later in the morning and cut out earlier in the evening. I don't see it as a problem though because the tubes are very effective at heating.

When on 7°, the pump might cycle quite a bit and increase wear.

What is the benefit of keeping it at 7, 10, or even 15, and what is your preferred setting (if you have the Geyserwise Max)?

I'm very impressed with how well this works, my geyser has been on holiday mode for more than a week already.

View attachment 1796445
Click to expand...
It will be also be less efficient given that the hotter collectors will lose more energy to the surrounding environment faster given the longer dwell time and higher temperature differential
 
Tim_vb said:
It will be also be less efficient given that the hotter collectors will lose more energy to the surrounding environment faster given the longer dwell time and higher temperature differential
Click to expand...
What is the longer dwell time you refer to? The time it takes for the collector to heat to the higher temperature?

The installer set the differential at 10°C, and it literally takes 2 minutes longer if I set it to 15.

I suppose the middle ground is best in this case.
 
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