If it is cycling on and off. It could be the pcb or the bypass in the header is stuck open letting it think its getting up to temp or the unitherm is stuck shut. Both of those conditions can make the sensors think the flow has reached temp. Does your unit hav metal or polymer headers?
That is an easy change, but all raypak heaters 400k btu and under have some sort of bypass to help regulate flow through them.
Well normally if it a sensor giving a bad signal there would/should be an error code.
Upon inspection of the pilot for flame rectification, you will notice the burner tube closest to the pilot is not in it's fully seated position at the rear of the tray. So you reposition it correctly and then check.Now the heater should function fully and stay lit. Apparently the tube is close enough for ignition but not close enough to verify ignition.------
That is an easy change, but all raypak heaters 400k btu and under have some sort of bypass to help regulate flow through them.
Well normally if it a sensor giving a bad signal there would/should be an error code.
Upon inspection of the pilot for flame rectification, you will notice the burner tube closest to the pilot is not in it's fully seated position at the rear of the tray. So you reposition it correctly and then check.Now the heater should function fully and stay lit. Apparently the tube is close enough for ignition but not close enough to verify ignition.------
Just get this checked.
Turn off the gas. Inspect the blue wire that leads to the ignitor. If you can't find anything wrong with the blue wire, bottum right side of the heater inside by the burner tray there is a 5/16 bolt that holds the pilot bracket in place. Remove the bolt/screw and gnetly wiggle and pull the pilot assembly back towards you and then down. You will have to maniplulate the pilot tube while doing that. Its soft aluminum so it has give, just don't kink it. Now with the pilot assembly in view turn the heater on, remeber gas off, and see if the spark is reaching. Also, remove the 4 screws on the side off the display panel and pull it up and forwards and make sure the blue wire is properly inserted in the ignition coil on the heater. At this point we have 2 items that can be the issue. A bad pilot assembly of a bad board.
Towards the bottum, about 2 inches up from the inside bottom, on the far right side is the pilot bracket. Its being help in by a 5/16 screw. The aluminum pilot tube and blue igniton wire got to the same place so If the blue wire is routed odly, then follow the aluminum tube. youre going to need a 7/16 wrench to loosen the pilot tube at the gas valve, unless you feel comfortable with making some small bends to the soft aluminum tube while you manuver the bracket and pilot out.
See fig below:--
See fig below:--
1= loosen and remove tube from gas valve.
2= I didnt circle the blue wire, the metal flap that the wire goes through has a 5/15 screw holding it to the heater, remove that.
3= thats the screw that holds the pilot assembly on to the burner drawer, no need to remove the drawer. Once loose, pull the assembly back about an inch and down
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click this link below, if you require manual:--
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page number 34,35,36,37 are troubleshooting pages.
