Plumber101010 wrote:
What doesn’t make sense is you are the second person to say that tank is not supposed to be full. But the screws were 2/3 of the way up and leaking so that tells me the tank not only had to be 2/3 full, because because the screws and the streaks are rusted, consistently 2/3 full as well and not sporadic.
Does that indicate maybe some kind of a malfunction with the tank filling up more than it should because of a blockage somewhere like a clogged filter? Sorry but I’m thinking like a plumber :)
No malfunction. You will find 2 lines marked. One on the upper half of the tank will be "-------HOT------" and one on the lower half of the tank will be "-------COLD-----".
When the system is not operating and has cooled down to ambient, the tank should not be filled more than the "Cold" line. When you turn the system on and it comes up to temperature, the fluid will expand and the level will go up to the "HOT" line. This is when your leaks would have occurred. When the system was operating, the fluid was higher in the tank and would weep around the screw holes.
Not sure what model you have, but you can find manuals here
http://aquahot.com/Library.aspx. Note that the older systems will be called HydroHot and not AquaHot.
For example, if you look at this manual
Click to View, there is a couple of excellent pictures of a typical system showing the heating exchangers and the expansion tank.
