Is there an immersion heater with wifi controllable temperature setpoint?

[Bramco]

Hi,

 

I can see 'smart' immersion heaters that reckon they can work out how much hot water is required but we're looking for an immersion heater where we can control the temperature setpoint remotely.

 

We use a diverter to dump excess solar into a 300L UVC with 2 immersions. There's only 2 of us, so normally we'd be OK with the setpoints set to say 45C but when the family is here, we use a lot more water, so could do with the tank being hotter, say 70C, so that we don't run out of hot water. Another scenario where it would be useful, would be when we're away for a while, if we could lower the setpoint until the day before we return, more solar could be exported, rather than being lost through the heat losses from the tank.  Not sure we'd ever recover the cost of replacing the immersions but .....

 

Anyone seen such a device?

 

EDIT - found one, the Tesla T-Smart -> https://www.tsmart.co.uk/ allows you to replace the thermostat in an existing immersion and control things from an app - nearly £100 on Amazon though...... 

 

Simon 

Edited August 9 by Bramco

[ProDave]

You are tackling this the wrong way.

 

If it is excess solar that you are mainly using, then set the immersion thermostat as high as it will go.  If you set it lower, then when your tank reaches say 45 it will turn off and your surplus PV will be wasted.

 

So let it just heat as much as it can while the sun is out, and if tomorrow is cloudy and not much sun, you will have plenty in the tank for another day.

 

I would also question if this will actually work for you?  Most solar PV diverters supply a pulsed or power limited feed to the immersion heater to match the amount of surplus solar PV.  I would expect this smart thermostat will be expecting a continuous power feed to it in order to operate, so I would not guarantee it will work when connected to the output of a solar PV diverter.

 

[Marvin]

Hi @Bramco

 

AS above from @ProDave

 

Yes to have temperature control away from the tank requires a digital thermostat that is adjustable and a relay switch to up the wattage is how its done here.

 

We have one but I set it to 74C all year as even in summer (is it summer??) we have dull cloudy days, some with mist, and so we like to have hot water that will last a few days without requiring buying energy.

 

We have a very insulated tank in an insulated casing.

 

M

 

 

Edited August 9 by Marvin
further thought

[Bramco]

2 hours ago, ProDave said:

your surplus PV will be wasted

It would be exported, so we'd gain that way but....

 

2 hours ago, ProDave said:

I would also question if this will actually work for you?

Hadn't thought of that!!    V good point - making my little thought experiment pointless!!  Ah well...  😄

 

2 hours ago, Marvin said:

We have one but I set it to 74C all year as even in summer (is it summer??) we have dull cloudy days, some with mist, and so we like to have hot water that will last a few days without requiring buying energy.

 

We have a very insulated tank in an insulated casing.

Ours is also set to somewhere in the 70s and in a highly insulated tank but it still loses some each day - from memory, when we've been away, about 3kWh per day (I'd have to check that though). So there's a constant 3kWh/day load.

 

Thanks for the replies @ProDave and @Marvin  maybe some day someone will come across this who hasn't got a diverter and will find it useful that there are such devices out there.

 

Simon

[JohnMo]

35 minutes ago, Bramco said:

t 3kWh per day (I'd have to check that though)

I would take at you pipes and see if you are loosing heat that way. Not being insulated or thermal gradient pulling the heat away.

[Alan Ambrose]

>>> immersion heater where we can control the temperature setpoint remotely.

 

You can do this (unofficially) with a Heatmiser set-up if you really want.

[Temp]

15 hours ago, ProDave said:

I would also question if this will actually work for you?  Most solar PV diverters supply a pulsed or power limited feed to the immersion heater to match the amount of surplus solar PV.  I would expect this smart thermostat will be expecting a continuous power feed to it in order to operate, so I would not guarantee it will work when connected to the output of a solar PV diverter.

 

 

Arrange for the WiFi stat to be powered off the regular mains and switch a relay coil. Have the relay contacts switch the output of the PV diverter to the immersion heater. 

 

 

 

[ProDave]

9 hours ago, Temp said:

 

Arrange for the WiFi stat to be powered off the regular mains and switch a relay coil. Have the relay contacts switch the output of the PV diverter to the immersion heater. 

 

 

 

Yes that is what is required, but I have a feeling the Tesla switch in the OP is not configured like that and would require a certain amount of alteration if it were even possible.

[JohnMo]

10 minutes ago, ProDave said:

Yes that is what is required, but I have a feeling the Tesla switch in the OP is not configured like that and would require a certain amount of alteration if it were even possible.

I did look at this, and it is just a electronic version of the normal thermostat, with bells and whistles. If you bypassed it you would no longer comply with G3 as your thermostat would not function.

 

You can control set points remotely, but not sure how you get it to function with diverter, as it is designed to be powered all the time and acts a thermostat and time switch.

[ProDave]

21 minutes ago, JohnMo said:

I did look at this, and it is just a electronic version of the normal thermostat, with bells and whistles. If you bypassed it you would no longer comply with G3 as your thermostat would not function.

 

From the link to the smart thermostat:

Safety

• Independent mechanical safety mechanism

 

So I expect the thermostat housing contains a relay and the normal mechanical over heat cut out, so it would still comply with G3.  But not if you start butchering it to give it a separate supply source.