Source of Basement Water

The water appeared while doing a load of laundry. We examined the washing machine and the water hose that attaches to the machine. There was no water under the machine. The floor drain is very near the washing machine so wondered if the drain was backing up. I watched the drain while my husband showered but there was no water backup and the water trail going to the drain was only on one side. The side opposite the washer.

That leaves the air conditioning unit and water heater that sit side by
side. Both units were sitting in water. We checked the pop-off valve on
top of the water heater but no water had flowed from it and there was no
evidence of water flowing down the side of the tank. The valve located at
the bottom of the tank was dry. The unit is two-three years old.

My husband suspected that condensation from the air conditioning unit was not draining properly, but that was fine too. He removed the door to check the interior of the unit. It was dry. As of today (Monday) we have hot
water and cool air so we still don’t know whether to call a plumber or a
HVAC expert to remedy this problem. So far, this has only happed one time,
but we suspect it will happen again.

We have the dehumidifier set on high to help keep the humidity level low in
the basement (the dehumidifier wasn’t the source of the problem either).
We would guess it was 3-5 gallons of water — hard to estimate the amount
of water when it’s all over the floor. The water was clean if that helps
to solve this mystery. Would appreciate any help you can provide.

Our Answer

OK, this is a long shot but your husband may be on to something. I have seen condensate back up and leak due to a temporary clogging of the condensate line, which may have cleared itself. I’d watch it for a while. It doesn’t seem like a huge problem and the more info you get, the easier it wil be to diagnose this.