Thank you all very much for responses and apologies for the delay in responding.  I will try contacting Thoren in the first instance and failing that will lok at some of your other suggestions

The first solution that comes to my mind is inspired (if you could say that) by the way IVT built their earlier pool heater control. When need for pool heat they just connect a regluar resistor to the outdoor sensor input instead of the sensor. Fooling the system that it is -20 °C.

Something similar by fooling the system that it is warm outside would work for most systems.

if so...

this is what you are looking for

Till ingången för tidstariff kopplas en slutande funktion från tidur eller energiverkets rundstyrningsrelä. Slutningen ska ske mellan ES3 plint nummer 8 och den gemensamma anslutningen 9. ES3 uppfattar slutning som högtariff.

To the input for economy tariff you connect and closing function from a timer or other relay. You close between ES3 connection point 8 and the common connection point 9.
When you do this.. the computer will consider the current state as a high cost tariff.

I assume this means that when you close this loop your heat pump will try not to start unless necessary.

You could basically buy a timer that will close/open a simple relay as per the time intervals you mentioned in your previous message.

I hope this is the computer you have, in which case the problem is easily solved. (given your other configurations of the heat pump are optimum from a tariff perspective)

Cheers

First of all, sory for posting in English.  I have a Swedish heat pump and expertise in this country are limited.

I'm running a Thor 05-15 GSHP (three phase) and have recently moved on to an EdF Economy 10 tariff. Without any sort of effort, 57% of my consumption is off peak (0430-0730, 1330-1630, 2030-0030). With a little bit of care I can improve on that (having showers, using the washing machine, at the right times). However I'd really like to be able to control the heat pump so that it only switches on at off-peak times.

I have a 500 litre buffer cylinder for the heating which should to balance things a bit and a 500 litre hot water cylinder.

I have tried playing with the heating a bit by putting a timer on the heating circulation pump - but by controlling the heat pump instead, I'd get the benefit of the buffer cylinder heat for longer. I could also live with the hot water in the cylinder until the next off peak heating cycle.

The heat pump control module is a Energi AB Stockholm Comfort Computer ES3 (if that means anything to anyone).

The system could be really good and efficient if the control module had a timer built in. I dont really want to fit one on the input to the heat pump as it triggers the 'loss of power' alarm. However if there was a way of fitting the timer between the main input and the actual pump control - that would be good. Or ideally reprogramming the module or buying a new one with timing capability in it.

If anyone can , I'd be grateful.

Thanks (and sorry once again for posting in English. My Swedish really isnt good