Originally Posted by Boerderij_Kabouter
I was planning on using my air compressor and blasting the water out...
I thought that would be sufficient, but now you have me momentarily worried. I think the air should be sufficient and any water left would just evaporate in a couple hours. I guess I don't really know.
My HERMS coil isn't 100% perfectly coiled such that there's water left behind in it if you just gravity drain it.
I think the problem is that even if it's mostly dry the remaining water has nowhere to evaporate really. Short pipes yes, but water in the middle of a 50' coil isn't going to easily evaporate and find its way out and around 25' of coil. Getting 99% of the water out and then circulating air for ~10 mins is probably needed to get it dry. (Hence the reason I was thinking shop-vac which I was already planning on buying for other projects).