Check the draft with a manometer.
Exhaust, tubing or the pressure switch may be clogged.
Should have more draft then the pressure switch is rated for at the pressure switch.
Could also be a sign of heat exchanger issues.
Exhaust, tubing or the pressure switch may be clogged.
Should have more draft then the pressure switch is rated for at the pressure switch.
Could also be a sign of heat exchanger issues.