HTP MODCON 850

Harvey Ramer

I'm working on one that has an intermittent error code F16 (flapper stuck open). I pulled the fan motor off and inspected the flapper. No visible damage. I tested the switch on the flapper by manually opening and closing the flapper. It's working fine. HTP says the venting on the unit is fine, i'm not sure I agree. The terminations in the attached photos are as follows, tee on the exhaust, downturned 90 on the inlet. The 2 pipes without any fittings are not connected to anything.
HTP recommends replacing the burner assembly. It's an expensive part.

Any thoughts?

DZoro

I'm with you, don't like the terminations. You are definitely bringing in exhaust through the intake. I'd move the intake elbows close to the building. Don't let them be any closer than 18" from the exhaust. Would also suggest the exhaust with a 90 up and then a horizontal tee. This should take all the exhaust away from the intakes, and move them further apart.
D

Henry

Inlet and outlets are too close together. HTP allows you to go up vertically several feet and more, then put a 45 with one foot of pipe. It prevents the combustion air from asperating combustion gases that screws up the fan and ignition system.

Timco

I see a real possibility for cross-contamination. Please email me direct at tim.white@htproducts if you continue to have issues after separating the intake and the exhaust or if you have any further questions or concerns. Glad to personally help. I will need model and serial numbers.

Tim

Harvey Ramer

Timco said:

I see a real possibility for cross-contamination. Please email me direct at tim.white@htproducts if you continue to have issues after separating the intake and the exhaust or if you have any further questions or concerns. Glad to personally help. I will need model and serial numbers.

Tim

Thanks Tim! I'll be in touch if I need further assistance.