Looking at a few youtube videos, I think I havent actually seen the HP controller yet!

The warmup device is usually for the mat type electric underfloor heating, commonly found in bathrooms.

I would say you are looking for a controller like pictured in @allyfish 's post here: https://renewableheatinghub.co.uk/forums/postid/22249

Or the controller to the right of the picture here: https://renewableheatinghub.co.uk/forums/postid/22470

From the outdoor unit, there will be control wire (commonly Ethernet network cable) going back inside the house, if you can trace that it will take you to the controller.

@aceshigh thanks for the info. The links are gold!

Can anyone tell me what this is? Could it be a thermostatic cut off for the water cylinder? It looks like its set to 44C which would account for her lack of hot water if it was.

Is it correct that the Grant will only heat hot water for an hour at a time or can that be adjusted in the controller menu?

Also on which controller would I adjust the time of DHW heating?

Thanks again in advance

@bontwoody the item circled is the cylinder thermostat. It displays the cylinder temperature. Turn the dial and the display changes to the set temperature. For a Grant ASHP about 55degC hot water is achievable if the Grant ASHP has been set to provide up to 60degC flow temperature in hot water mode. They are normally set to 55degC flow when commissioned, which will heat the tank to about 52degC. The LED lights on the thermostat flashes when the temperature in the cylinder is lower than set point, and continuous when demand is satisfied. Most of the time it will be flashing if hot water is timed once or twice a day.

The item above left of the cylinder thermostat is a wireless room thermostat interface. That’s likely wired into the Grant ASHP controller which looks like the item on the right below

@allyfish Brilliant thanks, I assumed the wireless room thermostat interface was connecting to the controller in my third image as they are both the same make (EPH). Do you think the DHW timer might be that?

I still need to find the Grant controller, it must be in another room.

Thanks again for the very early response 🙂

The wireless thermostat could be dual channel, heating and hot water. If there’s no other timer near the cylinder for scheduling hot water then the wireless thermostat controller might be controlling it. Good luck finding the Grant controller, it has to be there somewhere! The ASHP cannot be switched on or commissioned without it!

@allyfish LOL, thank you very much 🙂

I have a Grant Aerona, with EPH room thermostats. That is what is on your image #3, and the receiver is top left on the DHW cylinder in your image #2.

Mine is set up so the room stats control CH but don't touch the DHW. That's from a separate timer solely for DHW, and when there's DHW demand the CH receives no heat. This is a typical set-up for Grant's as per their installation manual (see here). I suspect you need to adjust the cylinder thermostat up (as suggested above) and then find the cylinder timer controls. Hopefully they are next to the Grant remote controller if you can find it(!)

The Grant controller is quite unfriendly. You just get 'parameters' and 'numbers' - no helpful words or pictures. See sections 7 and 9 in the installation guide for details, and section 5 for how the DHW should work (I think the mentioned Greenbrook timer is no longer used, so it could be a Timeguard equivalent which is what I have).

(I've attached an abbreviated installation guide I found which might be easier to follow as a quick start rather than the full Grant one)

@mikefl Thanks, so thats another controller! 🙂