John D wrote:

My Armstrong furnace, GUK100D20-1B, is noisey. When my furnace starts there
are relay click like sounds that are very loud and can be heard all over the
house.
When the gas control valve opens it sounds like a hammer hitting the pipes.
That's the worst of it but everything from control relays to the inducer fan
to the air blower fan seems noisier than it should be. In addition, a hum
from the blower(s) seems to conduct through the house via the duct sheet
metal and/or the PVC vent pipe. Is this a bad installation or what?

Either lousy install or lousy furnace. And I thought mine
was noisy.