HVAC unit making “knocking metal” noise when heat is on and when it goes off?
Iamme1979 asked:
what could be the cause of this?
We can hear it under the house even tho of course the HVAC unit is outside…..it’s like a knocking noise (just once) of metal against metal, with a slight echo……
What could be the cause of this?
We have a 1 yr warranty on the house, as we just bought it in August….is this worthy of a service call? what might they do to it?
I dont know who the contractor is, as it’s an updated 50yr old house, made modern. Is this something that the house warranty that the sellers bought, will cover?
heat pump install Chesterfield
what could be the cause of this?
We can hear it under the house even tho of course the HVAC unit is outside…..it’s like a knocking noise (just once) of metal against metal, with a slight echo……
What could be the cause of this?
We have a 1 yr warranty on the house, as we just bought it in August….is this worthy of a service call? what might they do to it?
I dont know who the contractor is, as it’s an updated 50yr old house, made modern. Is this something that the house warranty that the sellers bought, will cover?
heat pump install Chesterfield
air conditioner Mechanicsville
Rubbing of parts or bearings
Heating Repair Short Pump
This knocking is actually banging from incorrectly or weak crossbreaks on the ductwork.
When the fan comes on, the supply duct becomes pressurized and the return duct becomes negative.
When duct is made over a certain size, it has the familiar X formed into it to prevent the noise you are hearing. If it a bad crossbreak or is weak or doesn’t have one, it’ll do that. It also may be due to undersized ducts which I have seen mostly. The contractor probably put in the smallest duct he could get away with to save money.
If you can isolate where it is coming from you can screw some type of metal bracing across it to make it stop.
Have the contractor come out and fix it.
It is probably something not covered under any warranty but it is usually easy to remedy.