Hot water control with Heat Pump

[xanld]

I've just had a nest 3rd generation "Display-3.7" / "Amber-2.5" installed with my new GrantUK Aerona Air Source Heat pump. The Heat pump comes with a GrantUK remote controller for the water cylinder which also has an immersion heater on it's own timer.

The GrantUK remote controller is apparently set to "hot water priority" which means that the ASHP will always heat hot water, in preference to heating, until the water in the cylinder is up to temperature.

BUT I don't appear to have any control over the scheduling of the air source heat pump to control hot water. ASHP for hot water is always off, unless I press the button on the heatlink. Then I think the Nest is bypassed, and the ASHP starts to heat the water in the cylinder.

If I turn off 'manual' mode on the Nest, the thermostat controls the ASHP to heat the radiators. But it doesn't control the hot water.

I have set the Nest equipment to "Heat pump", but I think this is what stops me setting a Hot Water schedule. My installer is not so familiar with Nest (he wanted to install hive), but he says that it may be possible to set the Nest to "boiler" so that it allows control over hot water too - at least on a schedule. I understand the GrantUK controller should be aware of the cylinder temperature to cut heating when it is up to temperature.

Advice welcome.

[AlexD]

Thank you for all the information @xanld . I would be happy to try and assist. 

Keep in mind that the EU version of the Google Nest thermostat is only compatible with heat only heat pumps. It will not work with reversible or hybrid systems.  

We would recommend you get in touch with a Nest Pro if possible so they can have a look at the system and make sure it is fully compatible and set up correctly. Here is the link to the finder just in case. 

Now if it is a heat only pump and the water system is separate it may work. You can try and go to Settings> Equipment> Pro setup. Set the system there to "Other" and then the hot water control to "On/Off" if you are comfortable in trying so. 

Keep in mind that the Heat Link most also be wired in this case on both the hot water side, terminal 2 and 3 and the hot water side terminals 5, 6 or 4, 5, 6, depending on if you have a S or Y valve plan at the location. You can have a look at some installation and wiring examples here. 

[xanld]

Thank you @AlexD. My system is heat only, and I think I've solved it as you describe using equipment>other, and specifying electric for both heating and hot water.

Now I can control heating with scheduler/thermostat, and hot water with scheduler and the mechanical thermostat on the cylinder. 

[AlexD]

That is great to hear. Make sure to keep an eye on it for now to make sure it behaves as expected. If anything comes up, make sure to let me know. 

[AnaM]

Hey there,

Please let me know if there's anything else you need help with.

[AlexD]

Hey there, I haven't heard from you in a while so I'll be locking this thread. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community. Thanks, AlexD.