I have a Ruud hi-efficiency furnace and also a Ruud tankless hot water system, both with condensate lines running down to the pump.

My problem is... the pump runs (intermittently) ALL day long..lol.. it will fill up the laundry tub if I put the plug in... I can't tell if it's the furnace producing the excess condensate or the tankless heater.


thanks in advance!

  • Hello, and welcome to Stack Exchange. How much water per day are we talking here? Mar 9, 2018 at 2:51
  • that makes no sense ... both of those devices should be drawing outside air that is needed for combustion and exhausting back outside. ... you should not be getting the exhaust inside the house ... i think that the water heater has a leak and it is draining through the pump
    – jsotola
    Mar 9, 2018 at 5:30
  • separate the lines into buckets to assign blame to the right device, then work on that one.
    – dandavis
    Mar 12, 2018 at 23:26

1 Answer 1


It doesn’t seem possible to me for the furnace to produce excess condensate, it’s just a matter of how much hydrogen is in the fuel and how much fuel is burned. The water heater at least has a source of water - if there’s a leak in the heat exchanger it could combine with the condensate. Can you move one of the drain lines out of the pump, and drain it into a bucket to see how much you get from that source?

  • will do... will post after one days haul!
    – kerry
    Mar 9, 2018 at 4:35

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