Every time our Geo kicks on our lights dim for a second in the house. I have 2 friends with geothermal through different builders and neither have this problem. BTW this is a new home construction. With the issues I have been having with my contractor I am curious if this is normal or something else they f up'd. Thanks, Mike

Realativly normal , Call your power company and find out how many homes are supplied by your transformer , the problem usually leads back to there .

In my case with this problem, the electric company had to install a larger transformer.

Same here, we built in an older neighborhood and they put us on the same transformer with three other homes and we were the farthest from the transformer. Seemed odd to me since they wired our house for 400 amps and we shared a 500 amp transformer with three other homes. We complained for about three months, if our electric dryer was on and the geo kicked in all our clocks would reset, the TV would shut off and reset our Tivo's, very irritating. Our power company told us that was normal, until one of our neighbors complained as well. Now we have a transformer at our end and everyone is happy.