Diy GSHP

[RobLe]

Thanks for link, expect I’ll get some.  For now I used one of the other brass ones as it was easy to get, but I’ll get pressure rated ones - it’s annoying when stuff breaks.

The outdoor ground loops and the indoor rad system both have header tanks - so there’s no pressure to speak of by the way. 

I’ve been running with 3 groundloops for a couple of days rather than the usual 4, the system has to try a bit harder and the heating COP dropped from 4 to 3.7.  This is the worst time of year for the cop - the ground is cold, even though the air is starting to get warmer. 

[markocosic]

Dezincification?

[RobLe]

Uhhhh, it happened again the other day.  That is, another brass coupler cracked for no obvious reason (which I guess means fatigue failure after 3 years of 15C ish hourly temperature cycling), a litre or two of water+(non toxic) glycol came out, and the heatpump stopped.  Took me a day to notice (there’s lots of insulation at our house), Mrs RobL didn’t notice at all (even tho she’s sensitive to the 🥶 ).

I had already bought enough of the plastic 6bar rated fittings, so I’ll change them all over this weekend rather than one at a time as they fail…

[RobLe]

Of the eight 3/4“ hose tails for our gshp groundloop connections, two had completely failed within three years, and four were showing visible signs of a crack forming.  They’re all replaced with plastic now 🤞🏽