Hello - Mitsubishi Ecodan ASHP constantly shutting down and immersion using lots of KW

[Marcin]

Would this be right setting for water heating? My immersion seems to kick in when water reheats rather than pump. When I stop and re start it’s starting with pump. Can anyone advise?

[Marcin]

On 12/10/2023 at 17:10, Dave C said:

 

Certainly isn't what should happen! Some thing happened on my Ecodan after it was installed - heat pump would come on to heat up hot water cylinder, it would start heating OK, then in under half an hour would give up and switch over to the immersion, which I guess is the fall back behaviour for "we need hot water and the heat pump can't run for some reason". Turned out it was insufficient flow rate causing the heat pump to shut down - installer needed to reconfigure the water pumps.

 

Could try turning the water pump speed up, if it's a separate pump plumbed in and it's just got a simple dial or push button to switch between different pump speeds.

 

[Marcin]

Can you please tell me how did they reconfigure your pumps? Similar problem, ASHAP cuts and go to immersion to heat the water. I have this type but not sure how they need to be set if my problem is flow as well. Does anyone know how this should be set? I have underfloor heating and 2 radiators. 

[Dave C]

Depends how your pump(s) have been configured. If your pump(s) are set for the heat pump to control the pump speed - or if you have two pumps, but only one is coming on for DHW - then you might need to change the settings on the Ecodan; not sure what's involved in that. If the Ecodan is just telling the pump(s) to turn on, but not controlling the speed, then you'll be able to change the pump speed by turning a dial or pressing a button on the pump to switch it to a different mode.

 

You'll probably need to find the user manual for your pumps; it should tell you how to find out whether the pump speed is manually set or not, and how to change it if it is. Regardless, you'll probably need to observe what the pump(s) are doing when the Ecodan starts trying to heat the DHW.

 

Edited November 9, 2023 by Dave C

[Marcin]

22 hours ago, Dave C said:

Depends how your pump(s) have been configured. If your pump(s) are set for the heat pump to control the pump speed - or if you have two pumps, but only one is coming on for DHW - then you might need to change the settings on the Ecodan; not sure what's involved in that. If the Ecodan is just telling the pump(s) to turn on, but not controlling the speed, then you'll be able to change the pump speed by turning a dial or pressing a button on the pump to switch it to a different mode.

 

You'll probably need to find the user manual for your pumps; it should tell you how to find out whether the pump speed is manually set or not, and how to change it if it is. Regardless, you'll probably need to observe what the pump(s) are doing when the Ecodan starts trying to heat the DHW.

 

Can you please tell me how did they reconfigure your pumps? Similar problem, ASHAP cuts and go to immersion to heat the water. I have this type but not sure how they need to be set if my problem is flow as well. Does anyone know how this should be set? I have underfloor heating

 

22 hours ago, Dave C said:

Depends how your pump(s) have been configured. If your pump(s) are set for the heat pump to control the pump speed - or if you have two pumps, but only one is coming on for DHW - then you might need to change the settings on the Ecodan; not sure what's involved in that. If the Ecodan is just telling the pump(s) to turn on, but not controlling the speed, then you'll be able to change the pump speed by turning a dial or pressing a button on the pump to switch it to a different mode.

 

You'll probably need to find the user manual for your pumps; it should tell you how to find out whether the pump speed is manually set or not, and how to change it if it is. Regardless, you'll probably need to observe what the pump(s) are doing when the Ecodan starts trying to heat the DHW.

 

Hi Dave. Thank you for the reply. My FTC tells pumps to turn on rather than control their speed. One turns for water which is lowara and 2 pumps work when heating is on. I looked in manual for both and all settings could apply. I just want to ensure i have right flow within the system but unfortunately not able to decide which setting to choose for heating water, shower, floor heating and radiators. 

[sliderule]

You may have a problem others have had here. Your Heat Pump may be trying to complete the Legionella cycle and heat to 60C, with the help of the immersion, as the HP can't reach 60C itself. Sometimes the immersion overload clicks out so it doesn't heat, and the heat pump never reaches 60C, but keeps trying to. Our immersions have a reset button inside the cover (turn it off at the wall switch first!!). Or the immersion might be faulty and need replacing.

I hope this helps.