I need handy man's knowledge here. The condo my wife and I bought looks like apartments

[diabeticman]

two building side by side with 4 condo's in each. We are on the second floor. the upstairs condo have the furnaces in the "attic" crawlspace. My wife is often hearing knocking sounds.

Is it possible she is hearing the furnaces for both places (more the next door neighbors since our condo is warm with little need for the furnace to kick on.) that sounds like knocking. Not to mention it is raining.

I think she needs to turn off the Ghost stories....

[NYC_SKP]

1. Yes, it is possible.

You could be hearing sounds coming from equipment in the attic serving the adjacent unit or even downstairs units unless their's are someplace else, like in a basement.

You and she might be hearing fans or blowers or the furnace lighting up or the sounds that ductwork makes as it heats up and expands.

These are probably the most common sources of sounds, next to zombies!

Boo!

[diabeticman]

3. Thanks

[MicaelS]

2. Could be a real problem.

http://www.angieslist.com/articles/your-hvac-system-5-sounds-you-dont-want-hear.htm

http://inspectapedia.com/aircond/HVAC_Noise_Descriptions.htm

[diabeticman]

5. Thanks. Our furance is only 7 years old but the info helps.

[pinboy3niner]

4. BREAKING NEWS: Jason has escaped from the mental hospital again

[diabeticman]

6. Wasn't Michael Meyers in the hospital... AND Jason in the lake?

[flvegan]

7. I'd have a seat and enjoy a scotch and declaration evening.

Read your condo decs.

[blackcrowflies]

8. do you have access to the attic?

If the sounds are that frequent you or she should be able to go there and wait to see what's doing it.

I have baseboard heating. It makes little knocking and metal flexing sounds when it goes on.

Another possibility is air in water pipes, that sounds like knocking and is easy to fix.