Gas and Oil Home Heating Furnaces - dearborn heater pilot problems

I have a Dearborn natural gas heater that is about 12 years old the model number is DRC30CTN it has worked very well untill recently.When you turn it on it lights from the pilot but the burner will burn with only a small flame no matter how high you turn up the gas valve.The flame is a clean blue flame but remains small.This heater does not have a thermostat or thermocoupler on it,nor does it have a regular.It is hooked to the gas jet on the floor and goes into the gas valve on the heater.What could be causing this?I have taken the heater apart and blew out the burner and fittings.There is no restrictions in the burner.Can you guys help me out here?

Noone can help?I guess I'll try to fifure this out.Thanks anyway?

If this is the same heater you were having trouble with a year or so ago I suggest that you re-read that thread. There were a lot of suggestions in that thread, the most important in my opinion was to at least get it serviced by a professional if not just outright replacing it.

No not the same heatert this is a model DRC30CTN that other one was a DRC30ES,which I still wish I could fix it.Is there any place to get Dearburn info and help?

Do you have any other gas appliances in the place to know that gas is coming out the meter full bore? And is the meter valve fully open? Have you tried to disconnect the gas line by the jet or Dearborn valve and check gas pressure and check valve for a screen perhaps? If all that checked out, and that valve really has no controls or sensors, you'd think it have to be either a control dial that is stripped or the valve itself. I see online, doing a search, they only want $25 for a propane valve.

Other gas appliances work good.I supect it must be the gas valve,thank you for your time and help.