What are the possible causes of "water in the air pressure switch" on a condesating furnace? I have ran across this twice already this fall on Amana furnaces and distributor doesn't quite know why. Any ideas would be welcome, thanks
Water in the press switch or the tubing?
If tubing, take out any slack that causes lower-than-inducer level. The switch should be above the inducer to keep the moisture draining to the inducer housing.
I some cases water is held in the switch diaphram or tubes. Several pressure switchs have a minute hole in the hose bib.
The hole is too small to effect switch operation but large enough to relieve any negative pressure that may keep the water from draining.
Sometimes the hoses are pushed too far onto the hose bib. Now the tubing is covering this tiny hole preventing the water from draining away. (Think of your finger over the end of a drinking straw.)
Used to see this often on the York 90% several years ago when they first came out. On those we would raise the switches high enough to make sure the moisture could run back down the tubes. On a few of them, we had to cut the tubing and put a piece of copper with a .070 orifice size weep hole in it to allow fresh air to sweep the moisture out on the run cycle. I think they finally went to a different kind of pressure switch to solve the problems. Hopefully, just taking the slack out of the tubing to make sure it runs downhill will solve your problem. If not, I'd consider changing the pressure switch.
Is the furnca installed as horizontal left with the inducer motor at the top of furnace, whatsize btu's. If over 90,000 or horizontal left order a vent drain kit from manufacturer.
Shorten drain hose to eliminate any trapping.
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