HI Folks
As per the subject - does such a thing exist?
(Tried Googling - massive amount of hits .....)

Situation is - ground-source heat-pump to conventional radiators, which
all works well.
Programmable wall-stat in sitting-room - calls for heat, starts
heat-pump, temperature then rises slightly, turn off stat.

The heat-pump is just a big fridge-in-reverse - and takes a serious
amount of surge current to get the compressor spinning. It's said that
short-cycling (stop/start) isn't good for these units.... - and
common-sense suggests that, once started, it'd be wise to let the thing
run for half an hour or so each time..?

In an attempt to minimise this short-cycling, the engineers installed a
din-mount time-on-delay relay (8 mins or so), between the 'stat and the
heat-pump - idea being to sort of 'debounce' the call-for-heat from the
stat.
The pump itself is installed in the workshop.
When I'm working out there, I frequently hear the circulation pump start
up, then, after the short delay, the lighting dips & the compressor
starts - only to cut out again after no more then 30 seconds... This
can't be a Good Thing?

I did call the engineers back, who said 'oh no Sir, it can't possibly be
doing that' - and went away, promising to return.... that was some
months ago.

So - wondering whether fitting a programmer that's more capable would
make sense, or if the 'delay-on' timer should be changed to a 'run-on'
configuration....?

Any ideas, please?
Thanks, Adrian

Danfoss 40704