42flathead
New Member
Boiler pressure gradually rises to 30 psi. 2 zones are baseboard and 1 zone is in slab radiant heat. I have a spiro vent set up. My relief valve keeps popping off. The boiler ran fine until I hooked up the radiant heat. I am using a mixing valve to control the radiant heat temp. Do you think it may have air in the radiant system.