I recently started getting hot water coming from my cold water taps. It
stays hot for about 30 seconds before turning cold. I ruled out the taps,
and now I realize that the problem is happening at my furnace.
Nothing on my furnace has been changed recently. I have a tankless water
heater in an oil-fired Weil-McLain furnace with a 40 gallon holding tank.
Cold water gets fed into the loop that goes from the holding tank to the
tankless coil. This cold water line is heating up at the furnace and is
causing me the headache. I'm suspecting that the tankless coil in my
furnace is crudded up, and causing backpressure when the circulator kicks
in. This must be forcing hot water into the cold water side of things.
Does this seem possible?
Is changing out the tankless coil difficult? I can deal with stuck or
broken bolts on the face of it if that's the tough part. How much should a
Thanks in advance.
There is no check valve on the cold water coming into the system (although
there are check valves to keep the cold from flowing into the hot storage
tank). I thought of adding one, but I'm wondering why it worked for so long
It might be caused by an expansion tank losing its air charge, filling with
water, and no longer working. This might cause the hot water to back up into
the cold line as it is heated and expands.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.