Kernopelli
Veteran Member
- Joined
- Oct 16, 2006
- Messages
- 2,207
- Location
- Carterville, Illinois
- Tractor
- Mitsubishi MTE2000D, Dig It 258 Mini Ex, Deere Z930A ZTR
It's very early, I can't sleep because my back is killing me and I'm exhausted...plus it's been a while since I even thought about this stuff. I've owned a few boilers w/ baseboards but mostly just learned about low pressure hot water boilers while studying for stationary fireman and engineers license.....just hit the high points on these systems. anyway, you know what they say about opinions, everyone's got one...fill in the blank,etc.
I don't know if you have a diaphragm type expansion tank or the old style but if either hasn't been serviced and not working correctly, maybe you're PRV is occasionally opening and you're adding make up water to the system, which as Ken_CT mentioned will have higher O2 content and add to possible problems. Does the system have an automatic air vent or an air separator and is it working correctly? Also, as Chilly mentioned, the microbubble resorbers are a common solution and supposedly very efficient at removing even dissolved O2. I would be surprised if the air is coming from the pump seal, but I'm no expert. There are chemicals that can be added to system water to aid in removing dissolved O2, they're really for corrosion inhibitors and while healthy for some systems, probably won't help your issue. Don't know if I've helped, hurt or confused, but check and make sure that your system components are working correctly.
As far as why the expansion tank is on the output side, they are designed to compensate for thermal expansion which is going to be highest at this point. The water returning to the boiler has cooled significantly in comparison by the time it has returned to the other side of the circuit so a tank there would not be needed.
On Edit: Hey, I just remembered something.....I made a set of front weights for the tractor out of an old cast iron sectional boiler I took out of a property I bought one time....worked great. Just something to ponder if the frustration level drives you over the edge.
I don't know if you have a diaphragm type expansion tank or the old style but if either hasn't been serviced and not working correctly, maybe you're PRV is occasionally opening and you're adding make up water to the system, which as Ken_CT mentioned will have higher O2 content and add to possible problems. Does the system have an automatic air vent or an air separator and is it working correctly? Also, as Chilly mentioned, the microbubble resorbers are a common solution and supposedly very efficient at removing even dissolved O2. I would be surprised if the air is coming from the pump seal, but I'm no expert. There are chemicals that can be added to system water to aid in removing dissolved O2, they're really for corrosion inhibitors and while healthy for some systems, probably won't help your issue. Don't know if I've helped, hurt or confused, but check and make sure that your system components are working correctly.
As far as why the expansion tank is on the output side, they are designed to compensate for thermal expansion which is going to be highest at this point. The water returning to the boiler has cooled significantly in comparison by the time it has returned to the other side of the circuit so a tank there would not be needed.
On Edit: Hey, I just remembered something.....I made a set of front weights for the tractor out of an old cast iron sectional boiler I took out of a property I bought one time....worked great. Just something to ponder if the frustration level drives you over the edge.
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