Ice lolly anyone?

We suspect that the ground source heat pump collector array attached to this manifold is extracting far too much energy from the ground. When this happens, the fluid in the collector array will keep dropping as it has not had a chance to recover enough in the summer. Eventually ice will form on the outside of the exposed parts and if the temperature continues to drop, the fluid inside will drop below the limit of the anti-freeze and turn the garden into a massive block of ice.