It a bulb type and the cap tube runs on the other side also the hot/cold factor switch under the stat will light the hot light when it get to 230 degrees. its does not boil the water out of the cap I cool it off before it gets that hot. got the cap off with it around 210 and the water flows great also. The cap is also new. hopefully I can try to put the flex fan back on Sunday and see what happens, the electric fans may just not be able to do the job. Thanks for all of the input. Danny super250six
