I have a laars Newport oil boiler with tankless coil. The system is completely drained and when I fill the pressure relief valve leaks and psi goes over 30.
I have replaced the following
Expansion tank and air release value
New pressure relief valve and before pressure relief value there is also another air release changed that also
I also adjusted the pressure on the auto fill valve which didn't help so I put it back to Orginal setting
I see everyone posts turn off the valve that feeds the auto fill and see if psi keeps rising. I did that and the psi stops rising. But my problem is the shut off valve is before the auto feed valve and the copper that leads to coil in the same line so how else can I checkif iit's the coil or the auto feed
Thank you very much
You have to isolate the piping by cutting in another valve.