Pressure Loss of 5 lbs, no leaks

[trehugr]

For some reason I went from a normal 15 lbs at the EKO and 20 lbs at the oil boiler to 10 and 15. Any ideas ? Can a backflow / regulator go bad ?

 

[stee6043]

Failed expansion tank bladder??

 

[chuck172]

Do you have automatic air vents?

 

[trehugr]

Do you have automatic air vents?

I have the Taco vents on top of all the high points and they are all open

 

[Eric Johnson]

I wouldn't worry about it. Mine seems to vary over time, and it generally goes down on the wood side when the boiler cools off. If it's a problem with your expansion, tank, then you'll know about it soon enough, as the pressure will go the other way once the "air" side of the tank fills with water. More likely, your relief valve popped briefly at some point or something else happened (bleeder opened on a radiator or baseboard) to draw it down.

 

[trehugr]

OK... I wont worry. It did seem to take forever for the main floor baseboards to heat from 68 to 72 this morning. Not sure why, the extended cold spell, or maybe some air in the system. (I have a small leak at the return just before it goes back into the EKO ) but that never affected it before.

 

[chuck172]

Maybe you do have some air in the system and the slugs of air are finally finding their way to the vents (a good thing.) That would lower your pressure a bit.

 

[jebatty]

Assuming it's not air that worked it's way out of the system or the expansion bladder, a small difference in temperature can cause a big change in psi, depending on how much water you have in your system.