Anti-freeze mode for ecodan ashp

MultiFuelBurner

Spoonie_Turtle said:

DyfedWyn said:

Spoonie_Turtle said:

DyfedWyn said:

MultiFuelBurner said:

We have blue glycol (anti freeze) in our system which can be seen when you bleed a radiator upstairs above the cream carpet (handy colour lol)

However we have left our defrost setting to 5oC as delivered (standard settings)

The defrost cycle will not use the immersion heater (so let's get that out the way first so no big bills).what it does is it simply runs the heat pump in reverse and temporarily extracts heat from the water flowing through your radiators in order to melt the ice that has accumulated on the outdoor unit. So you pay for the electric pump to run that process for 2 mins.

Thanks for the response. The pump (not the ashp) seems to be on all the time the outside temp is 5 or below. Can this be right? My understanding (right or wrong) is that it keeps the water flowing so that it doesn’t freeze in ashp.

This us what ours seems to do, except I'm not entirely sure at what external temperature it kicks in - the heating goes off at 11pm (we don't need it to be 18℃ at 3am, and without a setback function setting a schedule was the only option) but there's a pump cycling all night long.  Really annoying! 
We have glycol in the system but I've not yet dared find out what the defrost temperature is set to as it says it requires switching the system off.  It's too cold to risk that it won't restart properly, especially as we've had a couple of issues in the last year of it losing connection and not working.

I think mine kicks in at 5 degrees. 

Are you seeing the temperature of your hot water in the cylinder dropping? Mine loses about 10 degrees in a night it seems.

I haven't particularly kept an eye on it, but I know it gets quite cool during the day anyway as it only heats up in the morning.  It's set to heat to 50℃ and the times I have noticed for whatever reason, it can be down in the teens by bedtime, especially this time of year.

I would agree I always put it down to losing more heat in the colder weather but perhaps it does draw some off 

I may well get the big manual out lol

MultiFuelBurner

So we heated the tank to 50oC accidentally at 1am Wednesday morning had 3 decent showers out of the tank. 

30 hours later the tank is sat at 24oC  so ours isn't taking anything from the hot water tank for defrost it's just pumping the water from the house (radiators etc) outside then back in for our off time of 10pm-2pm

addled

It's the Freeze Stat setting which keeps the CH pump running when the outdoor temperature drops below a specified level (5c default).  It will also run the heat pump occasionally to maintain flow at around room temperature.

Not related to the Defrost function which melts the ice off the outdoor unit when it's working hard. 

I originally turned mine off as it seemed to be of little benefit, with the pump churning away all night.  I re-enabled it last winter as we were below -10 on quite a few nights.  I imagine it may also help protect the compressor when cold starting.

This year I had the antifreeze checked and topped up as part of the service so it's off again for the moment.  Definitely turn off at your own risk!

The tank will always bleed some heat from the pipework. How much depends on where it is and what it's connected to.