Immersun quirk

[BruceB]

Installed an Immersun with a 1kW immersion last week. Immersun would not initialise as 'heater not detected'. Second Immersun behaved the same. Swapped over to the upper 3kW immersion on tank and Immersun initialised fine. Swapped back to lower 1kW immersion and Immersun worked, but after 20 mins said 'water hot' even though it was not and it was still supplying power to the immersion. After an email exchange with Immersun it is a 'feature', and they have issued a new firmware version that will allow loads down to 250W and will update if I send it back to them.

It is a bit of a pain as the customer is an hour away, but at least Immersun recognised the issue. A bit naughty as there is no 'minimum load' in the specification only a 'maximum load'.

I thought some might wish to be aware.

 

[Gavin A]

that is a bit naughty of them.

I assume that must be a minimum resistance value for the circuit or something?

 

[BruceB]

Yes, I think so. I cannot think of a good reason for setting the power level for detection so high in production models.

 

[BruceB]

Sent a unit back to 4ECO on Tue; they got it Wed, I received it back today Thu, with new firmware in. New firmware also includes a few other tweaks such as provision for wireless CT. So well done 4ECO for responding promptly.

 

[Gavin A]

does it have a timer function on both circuits? This is one of the modifictions we're waiting on.

 

[BruceB]

notes here
View attachment immersun fw 1.1.pdf

 

[Gavin A]

get in, dual heating circuit timers are a go.

for anyone wondering, this means they can safely be used on dual immersion tank set ups in a none domestic setting where the L8 legionella regs require heating to the base of the tank.