Water Inside Furnace

[cougar01]

I recently had a home inspection done on a house I am purchasing, and when they pulled the cover off of the gas furnace, there was water laying in the "tray" that is located below the burners. The furnace was operating fine. How does water collect there? Is this condensation build-up that simply hasn't drained away due to a clogged pipe or something more than this?

 

[friartuck]

It could be two reasons:

a. You've got a leak.
b. Condensation in the boiler.

If a. then depending on the type, you might get it repaired, but if you have had a leak, then your pipework might well be KO'd as well as the boiler. Get it checked out before you buy or you might be faced with a hefty bill.

b. Condensation. I assume that the boiler is not a standard condensing unit. But you can get condensation at start up or if the return water at the back end is low.
Start up condensation is not usually a problem but regular condensation will be. It will damage your boiler and flue (chimney). Get a plumber to look at it.

Friar Tuck of Sherwood

 

[rmw]

The rain cap on the flue duct could be missing or mal positioned or damaged. If the flue duct is metal, the seam in the metal could be leaking.

rmw

 

[imok2]

Indoor air contains traces of commonly used household products such as bleach, paint strippers, and so on. Condensing furnaces have been known to corrode rapidly if fed indoor air contaminated by these common products. Most manufacturers void warranty coverage for furnaces operated in a contaminated atmosphere. Even fabric softener and salt from water softeners have been suspected culprits. Unless the furnace is near a possible source of contaminants, such as a dry cleaning shop, outdoor combustion air is much better for the furnace. (Salt air near the ocean would probably also cause problems for condensing furnaces, but the only salt water we see in Wisconsin is when the snow melts in the road.) There is mounting evidence that even furnaces in the 80% AFUE range have problems when using contaminated air for combustion. The contaminants cause condensation and corrosion to occur more easily.

 

[cougar01]

Thanks All to your responses. The furnace is a standard condensing furnace. It was approximately installed in 1997, and there is a PVC flue duct going to the outside of the house. If I recall correctly, the PVC pipe did not have any type of cover on the end of it on the outside of the house. So, I suppose from reading your replies, my problem could be either water entering the PVC due to the missing cap, or that the condensate to floor drain PVC pipe may be clogged?

 

[Rodale]

All condensing furnaces have a drain. Raining should just go down the drain. A cap is not necessary. If it rains too much the furnace will shut off till the drain clears.

The secondary heat exchanger may have holes. That can allow the condensate to leak to the division plate. Not all of the presure switch safeties will open with a leaking secondary.