the pipe between the house and garage is 22mm and probably undulates a bit.
I did try without the pump running but it didn't really get hot (perhaps i wasn't patient enough)
Very similar layout,
Both underfloor manifolds have been pumped to clear any air, I can only think its air in the pipe between the house and garage.
[/img]http://www.diynot.com/network/rainman/albums/22944/85704]
Please can someone help on this one? Did you resolve your issue?
I have the exact same issue with a Gledhill open vented thermal store.
My setup is almost identical apart from my heating circuit is underfloor and I don't have a wood burner
When the pump starts water is drawn in from the...