Modine Heater burner problems

[Pleun]

Hi, New to this forum
Have a Modine PDP 350 Modine, I am having some issues with. Have had several heating "experts" at $100.00 per hour look at and they cant figure it out.
Here is the issue. I turn the unit on and it fires up no problem, all the burners work good, nice blue flames. However the flames are only about an half inch tall and it also releases unburned propane into the air.
I turn the unit off and on and it fires up again and now the flames are about inch and half tall and no smell at all (working properly)

Any ideas????

Obviously it is getting enough fuel?

Thanks in advance

 

[htmdude57]

Did any of the experts use a manometer to see what the gas pressure was before and while running?

 

[The Cobbler]

with you smelling propane and it is a power vented heater, I would be looking for a leak at/around the gas valve I think

 

[PoorUB]

I used to work for a wholesaler that sold Modine. The Modine PDP units are notorious for the burner nozzles not lining up proper with the burners. I would find information on that and make sure the burner is set up properly. I don't have access to the info, but any wholesale that sells Modine should have the info, or be able contact Modine.

For whatever it is worth, I don't recommend the PDP. Modine has a PTP for a few dollars more that is a better heater.

 

[naturalgas]

It’s got to be a solvable problem. I don’t know how these guys can charge you when they walk away with no results.


Sent from my iPad using Tapatalk

 

[gmcgeo]

Check the pressure before then after the gas valve with a manometer.
I have seen the gas valve stick and not open fully causing less pressure then needed into the burner tubes. turning it off then back on sometimes can jolt the gas valve opening it fully.

however you can test this with a manometer at gas valve on the manifold side. you should see about 10" water column on manifold side. that's what the manufacture wants to see. if you see less then 9 then the gas valve is malfunctioning. " as long as the regulator out side is pushing 11-13" water col" for propane that is

if not that then check for clogged exhaust pipe, and that the power venter is coming on and not clogged.

sounds more like a gas valve issue to me though