Low temperature rise -help

[linas]

Originally posted by just_opinion
8.75 Mbar is equivelant to 3.32 IWC. This reading is the inlet gas preessure or the outlet gas pressure?

This is outlet presure

[Mod3]

Unfortunately, due to site rules we as members can not discuss technical issues with the general public.

Thank you for your cooperation.

[MechAcc]

Originally posted by linas
nozles are Nr.43 original, presure 8.75Mbar like recomended, gas usage in norm. I do not know what I can change.

Gas orfices can agglutinate, restrict, just like oil nozzles with debris. Very small contaminates in the gas and at the furnace location will collect in the orfice opening. It takes a much longer period of time but it does happen. So you may have correct gas pressure to the burner orfices but not the correct flow.

[MechAcc]

Originally posted by troyorr
Slow your blower down.

It is already on low.

[just_opinion]

You just inherite this unit or you have it for awhile?
I don't think gas is you primary reason. Look for duct leaks
I am surprise to hear the 3.5 IWC (EXACTLY) per manufacture recommend when you measure it at the outlet.
If you are the home owner please call the professional
If you are the professional, please go back to school go to the pro forum

[atphvac]

Is this thing in a garage without any ductwork?

[7X]

High vent temp and low air temp rise? Is the inside of the heat exchanger sooted up?