I thought it was I went to the townhouse, until I read that the tech and his son(very unprofessional way) worked in the townhouse.
You will be happy when you see your next gas bill, and happier when you see the bill next winter.
The most important concern is tell what the brand of furnace and which company you dealt with.
Thanks lots.
动手前三思:你真的需要高效暖气炉吗?