Furnace condensate drain

Old 12-20-03, 02:52 AM
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Question Furnace condensate drain

I am building a vacation home and the Mechanical inspector says I have to drain the furnace condensate lines from my high efficiency furnace to the sewer line. My question is, if I install a trap and hook up to the sewer line how would I keep sewer gas from entering the house in the summer when the furnace is not running and the trap water has evaporated?

There is no A/C and the sewer drains to a septic system. Currently I have the condensate lines draining into the crawl space. Thanks for any help offered.
Old 12-20-03, 04:57 AM
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Install a quarter-turn ball valve on the condensate line and just shut it off when the furnace isn't running.
That's one way to prevent sewer gas.
Good Luck!
Old 12-20-03, 06:15 AM
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Usually an indirect drain is used such as a convient floor drain.
Barring this, there are traps made for commercial units for this application. Really nothing more than an open p-trap attached to an open vertical stack. There is a funnel looking top on the assembly the condensate line drips into. There is also an automatic trap primer ran to them which addresses the dry trap issue you raised.

Hope this helps, more questions, ask in this thread and someone will respond.
Old 12-25-03, 05:11 AM
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Thanks for the help, much appreciated!
Old 12-25-03, 09:41 AM
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You could put RV antifreeze in the trap in the summer it won't eveporate and you don't have to remember to change anything comes the fall

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