As per picture from the NIBE app, does anyone know what the meaning of El. add. heat is?

Sometimes it is OFF, sometimes ACTIVE and them sometimes says BLOCKED?

 

Cant find anything in the manual to explain this.

I would say Electrical Additional Heating, i.e. a resistance heating element aka an immersion heater, probably used if you want the DHW too hot, for a legionairs heating cycle or if it is just too cold for the heat pump to work properly.

Yes I thought something similar, the BLOCKED bit is worrying me though, although when it appears there are no error messages being sent through.

It is Additional Electrical resistance heating, but for my Nibe it's integral in the heat pump and separate to the immersion in the DHW tank.

I keep mine 100% Blocked so that it's never used, but my HP is overs-sized so can comfortably cover heating and DHW requirements.

"Blocked" will be in your controller settings.

 

But can also be blocked by Schedule and/or Schedule Blocking

Edited January 15, 20242 yr by IanR

Thanks, I have a seperate immersion heater for the tank too.

So I could switch it off then?

4 minutes ago, Chriswills said:

Thanks, I have a seperate immersion heater for the tank too.

So I could switch it off then?

Additional Heat can be switched off (Blocked), if the Compressor can cover all heating and DHW requirements at all temps. Try it, and if you find it's not managing to heat the house sufficiently put it back on. You may need to extend the ASHP running time if it's currently using additional heat regularly.

 

I found the Nibe Controller brought it on unnecessarily. Biasing "Comfort" over efficiency.

I wouldn't switch the UVC Immersion off. It's likely used for Legionella cycle.

Edited January 15, 20242 yr by IanR

Is there a saving on bills without it? Mine seem high

8 minutes ago, Chriswills said:

Is there a saving on bills without it? Mine seem high

Yes. For the portion the "Additional Heat" is being used you're achieving at best a COP of 1. ie. 1 kWh of electricity for 1 kWh of heat into the house. If you can leave all your heating and DHW requirements to the compressor, you'll be achieving 2, 3, 4 or 5 times that - depending on the difference between outside air temp and flow temp.

I have tried it for a few days and cant really see any difference in electricity usage with the add heat OFF