[fried]

Hi, I have a new propane gas furnace installation (we converted from oil). Everything seemed fine, except that the ground fault tripped in a bathroom, they tried the air conditioning, but it will run for a few seconds and then stop and at this time the furnace will turn on. They could not explain why this is happening. Now we tried to use the central vacuum and the motor won't turn on, even though there is power to the unit. What did they do? Somehow I feel all these things are related, please give me an insight on how these things are related. The contractor will send a service person tomorrow but I need to know what is happening.

 

[Yoyizit]

I'd start troubleshooting by disconnecting the few wires that connect their new work to your house wiring.
If your house elec. things do not then return to normal operation then something(s) in your house has/have been damaged or your existing house wiring has been altered.

BTW, how old was your previous furnace?

 

[fried]

Our previous furnace was 35 years old. I am wondering if there is a problem with the phases.

 

[Yoyizit]

Thanks.

As another possibility, I'm now wondering whether there was a latent problem in your house wiring that is only now showing up because of the new installation.

 

[fried]

Any idea on what kind of problem?

 

[Speedy Petey]

I wouldn't do a damn thing!
Tell these bozos to get their NEWLY installed system working properly. Period.

 

[Yoyizit]

Any idea on what kind of problem?

Not without doing some troubleshooting. This kind of problem after a routine installation seems to be unusual.
My first guess would be improper installation. 2nd, a problem in your house that may have been there for a long time.

Here's the whole list, courtesy of Wiki

A [installation] may be the cause of B [house problems].

B may be the cause of A.

some unknown third factor C may actually be the cause of both A and B.
there may be a combination of the above three relationships. For example, B may be the cause of A at the same time as A is the cause of B (contradicting that the only relationship between A and B is that A causes B). This describes a self-reinforcing system.

the "relationship" is a coincidence or so complex or indirect that it is more effectively called a coincidence (i.e. two events occurring at the same time that have no direct relationship to each other besides the fact that they are occurring at the same time).