Heatilator NDI35-c Trouble

[Nickster8074]

Hello, I’ve been reading through other similar Heatilator posts and haven’t really seen anything similar to my problem. This is a remote controlled unit which hasn’t been functional for nearly a year and a half.

I click the button to start the unit, the pilot lights and the main burner lights, but weakly. Literally you can watch the holes fill in the burner one by one. When this unit was installed in 2016, I seem to remember a whoosh when the main burner lit. When I toggle the remote between high and low flames, nothing changes in the lazy flame. I do hear the relay click inside the main burner solenoid.

I have checked the readings for the inlet and manifold pressures. Inlet measures 6 in and the manifold measures 4.5 in, which is a bit high. I don’t see any way to change the pressure. The valve itself is a Dexen 750-500 unit.

Any thoughts or suggestions would be greatly appreciated. Seems like all the elements are there, just can’t get that whoosh.

 

[DAKSY]

Have you pulled the burner, removed the burner orifice &
checked the gas tube behind the orifice for blockage?
Try sweeping it out with a Q-Tip or pipe cleaner.
Spiders build nests in that area & stop the gas flow
from the valve to the burner.

 

[Nickster8074]

Have you pulled the burner, removed the burner orifice &
checked the gas tube behind the orifice for blockage?
Try sweeping it out with a Q-Tip or pipe cleaner.
Spiders build nests in that area & stop the gas flow
from the valve to the burner.

I’ve pulled the burner and removed the orifice. There was nothing in the initial inch or so, then it turns hard 90 degrees and heads down toward the valve. I will plan to pull the entire line from the valve to the burner tomorrow and blow it out with compressed air. I can also run pipe cleaners through it to be sure. I’ll report my findings.

 

[Nickster8074]

RESULT! I pulled the line and burner, blew/pipe cleaned them out. I saw just about nothing come from either part.

Since I was in there, I did some reading about the solenoid the controls the flame height. It’s the black box with 2 orange wires coming from it in my pic. I looked up the part number and found instructions for install. Says to turn 2 full turns and tighten the jamb nut. Looked at mine and it was screwed in to the hilt. Reinstalled it per the instructions.

Once back together, I got my whoosh! Flame wasn’t huge, but had gotten much bigger and was providing nice heat. Clicked on the high low flame button on the remote, no joy. Clicks like a before, just no flame adjustment. Given my findings, the flame adjustment solenoid seems to be the culprit.

If there is some fine tuning info for this solenoid or the main flame valve itself, I’d love to hear it! Thanks for your first reply, it seems to have me paddling in the correct direction.