Can't get psi on Weil McLain oil furnace below 30

[Thomas Gandolfo]

I have a Weil McLain oil furnace (16 years old). Woke up the other morning to several gallons of water on the basement floor from the pressure release valve doing it's job. PSI was 32 and release valve set at 30. The plumbers came and did the following: 1) replaced the pressure release valve and the water feeder valve with brand new ones. The new water feeder valve was pre-set to 15 psi. They replaced the expansion tank with a brand new one also. They also checked the water pressure coming into the house from the city water line. It was 80 psi so they installed a pressure regulator there and set it to 60 psi. They also checked the 80 gallon Weil McLain water heater as they said sometimes that is the problem. That checked out okay. Lastly they drained some water and brought psi down to 15. Over night it slowly crept back up to 30 psi. I feel like we have tried everything. Plumber coming back later today, but would love to get some advice from this forum. Do I need to replace the entire furnace?

 

[Reach4]

If this boiler also heats your hot water for washing, that heat exchanger, may be leaking potable water into the boiler water. There have been some troubleshooting discussions along that line. That heat exchanger may be a separate unit.

 

[Sponsor]

 

[Thomas Gandolfo]

If this boiler also heats your hot water for washing, that heat exchanger, may be leaking potable water into the boiler water. There have been some troubleshooting discussions along that line. That heat exchanger may be a separate unit.

Thank you. I do have an indirect water heater that feeds off the boiler. It is 16 years old. Just had a brand new Viessmann tank delivered this morning. They will hook it up later today. Hopefully this fixes the problem.

 

[Thomas Gandolfo]

Looks like replacing the water heater did the trick. The new one has been in place for about 20 hours now and all good. PSI is now ranging between 16 - 19.