Solar iboost not working

[Grumpy_Wombat]

After some though, a couple more comments, of a technical nature.

Firstly, the power boost button is indeed a switched relay, that was never in doubt. The purpose of the boost test was to check that the immersion heater, thermostat and safety stat were all working. Given the information provided it seemed pretty inevitable that they were, but given the difficulty of diagnosing a hard fault here worth the check.

The iboost output device appears to be a triac (and not zero volt switched either so I hate to think of the power factor implications). Lovely to think that the triac, as a device is over 60 years old! However, it does not seem likely to me that this has failed. As we know such devices usually fail open or short circuit.

If the device failed short circuit then the tank would always heat, irrespective of any other input. This is known not to happen.

If the device failed open circuit, and this is conjecture, then no power would be fed to fed to the immersion. This is a similar situation to the tank being fully heated where the hot when the immersion stat is open circuit. Under these circumstances the iBoost detects the lack of power and displays the message Water Tank Hot.

Therefore, if the output device is open circuit I would expect the iboost to always display Hot and not Off as reported.

Regrettably again, not helpful in making a definitive conclusion.

 

[davesparks]

Mary 12345: Because it is no cost and easy to do as a test - please reverse the direction of the clamp and see what happens.

Further to this, once you have reversed the direction of the clamp, switching on a higher power appliance such as a kettle will cause the iboost to see the power flowing in to the kettle as if it was excess solar generation (because the current sensor is reversed) and so the iboost should then switch on the immersion heater.

This is detailed in the manual as part of the setup procedure to check that everything is working.

 

[Grumpy_Wombat]

except that we know everything is not working ….

 

[davesparks]

except that we know everything is not working ….

Yes, but every bit of information can help, and this is easy and free to carry out.
Don't dismiss something just because it seems unlikely to help.

 

[Grumpy_Wombat]

Might be better if you had mentioned that for this to work during the daylight (and sunny hours) you need to shut down the solar first (exactly the opposite of the suggestion). Obviously, if the solar is generating more than the kettle the test will be very misleading because it will appear that the test fails when in fact it was meaningless.

A potentially more effective test (and doesn't require solar shutdown) is to move the current clamp to the supply to the consumer unit in the correct direction. If the house is taking more than a few hundred watts (likely) the iboost will enable the immersion heater and then positive feedback will drive iBoost to the full 3Kw within a few minutes.
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One for you Mary (and not detailed technical). Going back to your original post I believe you say that when you switch iBoost on the blue "lightening" flashes and the iBoost powers the immersion heater and then the power quickly falls away. However I don't think you mentioned (if you did sorry) what happens once the iBoost goes to off.
Does the iBoost blue light flash anymore and at this point does the light on the sender continue to flash? (assuming it's sunny).

 

[davesparks]

Might be better if you had mentioned that for this to work during the daylight (and sunny hours) you need to shut down the solar first (exactly the opposite of the suggestion). Obviously, if the solar is generating more than the kettle the test will be very misleading because it will appear that the test fails when in fact it was meaningless.

A potentially more effective test (and doesn't require solar shutdown) is to move the current clamp to the supply to the consumer unit in the correct direction. If the house is taking more than a few hundred watts (likely) the iboost will enable the immersion heater and then positive feedback will drive iBoost to the full 3Kw within a few minutes.

Yes I was not clear enough about that, thankyou for clarifying this for the OP.

We all make mistakes, or assumptions from time to time which can be incorrect. Such as your assumption here that the PV is connected to a seperate CU and not to the same CU as the rest of the installation, or indeed that there is only one CU for the installation.

 

[Grumpy_Wombat]

I'm not sure where I assumed that the PV was connected to a separate (BTW separate is the correct spelling) CU or indeed any such assumptions.

You might, of course, be referring to my "Mistake" dealing with the fused spur. I have since checked and the Marlec installation guide suggests that a 13 amp fused outlet is fine. And of course it is recommended that a double pole switch is used so the part suggested would actually be better than many 13 amp sockets because of the double pole - although, to be fair, there are now double pole switched 13 amp sockets.

But I agree, we all make mistakes ....

 

[Grumpy_Wombat]

I apologise. Whilst my content might have been OK, the delivery was less that which we should aspire to. And it's not great for our "client" either.

 

[Tommy1947]

Hi, I've now had my SECOND Solar iBoost+ fail on me ! I've had it installed by a qualified electrician in accordance with the instructions and also had the immersion heater element checked OK. It is very frustrating especially as I'm losing all this sun to save me money
Am I just unlucky or are these fickle in their design ?

 

[Crusty_Man]

We have had solar Iboost+ installed in 2018, but it was bought in mid 2016, direct.

It runs 2.5kw oil heater, & has always worked fine. However at 8pm tonight, in walking past it, it was red hot,
the solar panel display said it was off, & it had saved 4.6kwh today, however a bit later it said it had saved 16.4
today, & bit later it had saved NIL, I tested out the connections, with no solar panel power being produced,
On the IBoost, the input was 240v, but circuit A, ** was 520V no load ** B=Nil. Unit said it was OFF.

I have emailed Marlec tonight, this is very concerning, I would have hoped it it went defective, it would be dead,
520v live, when you expected it to be off, & it said it was off, could have been a killer.

 

[bmcn85]

We have had solar Iboost+ installed in 2018, but it was bought in mid 2016, direct.

It runs 2.5kw oil heater, & has always worked fine. However at 8pm tonight, in walking past it, it was red hot,
the solar panel display said it was off, & it had saved 4.6kwh today, however a bit later it said it had saved 16.4
today, & bit later it had saved NIL, I tested out the connections, with no solar panel power being produced,
On the IBoost, the input was 240v, but circuit A, ** was 520V no load ** B=Nil. Unit said it was OFF.

I have emailed Marlec tonight, this is very concerning, I would have hoped it it went defective, it would be dead,
520v live, when you expected it to be off, & it said it was off, could have been a killer.

We have had solar Iboost+ installed in 2018, but it was bought in mid 2016, direct.

It runs 2.5kw oil heater, & has always worked fine. However at 8pm tonight, in walking past it, it was red hot,
the solar panel display said it was off, & it had saved 4.6kwh today, however a bit later it said it had saved 16.4
today, & bit later it had saved NIL, I tested out the connections, with no solar panel power being produced,
On the IBoost, the input was 240v, but circuit A, ** was 520V no load ** B=Nil. Unit said it was OFF.

I have emailed Marlec tonight, this is very concerning, I would have hoped it it went defective, it would be dead,
520v live, when you expected it to be off, & it said it was off, could have been a killer.

I've also just had this fault. The unit shows 'Water not heating' but the blue lightning symbol flashes. The iboost buddy was showing as importing 3kw so I checked the unit and it was heating immersion heater 1 (showing 480v). I also noticed that even when the panels are producing (say 800w), the unit will show 'heating by solar 2.7kw'. Yet the iboost buddy will show as importing 2kw.