Rad heating not bleeding properly on two rads that either get barely warm or half warm.

You have air lock in the system need to blending rad

Hello, before assuming there is a major problem, a few things should be checked. The radiator bleeders need to be working properly, the boiler system needs to have adequate water pressure, and the circulation pump should normally be off while bleeding the radiators. Each radiator should be bled until the trapped air is released and a steady flow of water comes out. The expansion tank and system pressure should also be checked to make sure they are operating properly. If the radiators still cannot be properly bled after these checks, then the system may need further troubleshooting to determine why air is remaining trapped or not reaching the bleeders.