Prestige Excellence saying low water pressure but......

[Irishjedi]

I have Prestige Triangle Tube Excellence boiler hanging on the wall. It is reading "Low water pressure has fallen below 10 psi. Boiler will automatically reset once water pressure returns to normal'. However, according to the psi gauge on the front of the boiler the psi is at 20. I did change out the relief valve a couple days ago because it was leaking. Also, I did shut off the unit and turn it back on to see if it would reset, to no avail. Usually a little pull on the expansion tank valve will set it straight and increase the pressure but I was already above 10 so I didn't. Any thoughts on what could be causing this? The unit is about 4-5 years old.
Thanks,
Jon

 

[Sylvan]

Did you check the low water cut off (reset)

I would check the pressure using a different gauge as possibly one on the boiler is not working properly to cause the relief valve to leak as normally they are set @30 PSI

 

[Sponsor]

 

[Reach4]

Your thermal expansion tank should be empty when the pressure is normal. If your tank failed somehow, you would expect the pressure to rise excessively when the boiler turns on.

A new gauge makes sense. But knocking on the pressure tank to see if it sounds totally empty when the pressure is down could be helpful. Therm-X-Trol is a good brand.