HVAC Experts? Propane Heater Question..

[mtholton]

I've got a case of beer or two coming your way if you can help solve my riddle! Name your price!

We had a direct vent heater installed a little over a year ago (model below).

https://wildoaktrail.com/products/m...yyDh_WgROO6N1EY7Ars63aUqPCPKtA9saAqFMEALw_wcB

Worked good until we tried it for the first time this fall. We can get it going, but if we turn the dial up below the lowest setting, the flame dies out. We had the pressure tested and it was 11 w.c. and the manufacturer told me today it should be 14 at the inlet. The guy that did the testing on it stopped by when we weren't there and determined he didn't want to mess with it... I know nothing about this sort of thing and I've tried every hvac place within driving distance and I think everyone is too busy to want to take on a little project like this.

If I'm running propane from a 20lb tank, through a lp regulator, and its coming in at 11 w.. at the unit (which I understand to be a standard amount for a lp setup), how do I "turn it up" to 14 per the manufacture? Do they make adjustable regulators or am I thinking about this wrong? Again, it worked fine the year prior... We replaced the regulator to rule that out...




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Below is the troubleshooting the company suggested.
We are sorry for the inconvenience. See below for possible adjustments on the control valve. If the device still does not work after the settings, you will need to contact the installer so that he can send us the detailed report of the installation, basic tests carried out for the safety and proper functioning of the device, as well as the IN/OUT gas pressures of the control valve. Please also add your name, address, phone number and a copy of the invoice, and if you qualify for the warranty, we may send you the necessary spare part(s) if it is defective.
Troubleshooting for the MDV

The thermocouple must be checked with a standard voltmeter set to the “Ohms/Continuity” function to determine whether the probe circuit is open or not.
If the problem is related to a short rod between the control knob and the control valve, no replacement is available. However, we can recommend to insert a piece of aluminum foil (equivalent to 1-2 mm) into the control button to lift it, see the attached file "IMAGE A".
Screw #3: turn a quarter turn to the left to ensure burner flame stability.
Screw #6: Pressure should be between 13°W.C. and 14°W.C.
Screw #7: The pressure should be at 11°W.C., the adjustment is made using screw 2. Screw #6 should be adjusted before screw #7.
Screw #5: Adjust the driver to cover the thermocouple.

 

[jsasker007]

It says in the manual that 11wc is the minimum. 10.5wc for manifold pressure. Sounds like you should be fine. Being that it worked last year with the same set up I don't know why you would need more pressure this year. Maybe check the burner for build up of soot or maybe you had some mice put something in there?

 

[mtholton]

It says in the manual that 11wc is the minimum. 10.5wc for manifold pressure. Sounds like you should be fine. Being that it worked last year with the same set up I don't know why you would need more pressure this year. Maybe check the burner for build up of soot or maybe you had some mice put something in there?

That was my thought as well. The support guy says hes 99% sure its a pressure related thing... We've cleaned it all out with a shop vac etc. We've probably only got about 7 nights of use out of it in total...

 

[jsasker007]

Could try a new 20lb tank just to make sure it's not a screwed up valve on the tank and you have enough lp to run it. Those rubber lines can dry out and crack over time also. Maybe make sure you don't have any cracks or pinholes. If it's a hard line from the tank to the furnace then the line shouldn't be the problem. If you have made any adjustments to anything I would try to get everything back to the original settings

 

[jsasker007]

Maybe a sunflower heater that screws on the 20lb propane tank is in your near future? They work and are easy to use until you get your problem figured out.

 

[mtholton]

Could try a new 20lb tank just to make sure it's not a screwed up valve on the tank and you have enough lp to run it. Those rubber lines can dry out and crack over time also. Maybe make sure you don't have any cracks or pinholes. If it's a hard line from the tank to the furnace then the line shouldn't be the problem. If you have made any adjustments to anything I would try to get everything back to the original settings

Tried a new tank...

 

[mtholton]

Maybe a sunflower heater that screws on the 20lb propane tank is in your near future? They work and are easy to use until you get your problem figured out.

We have a wood stove as a backup, but it turns the 12x20 shack into a sauna...

 

[jsasker007]

Does the furnace have a pilot setting and a run setting? Like a regular house furnace you start it on pilot and switch over after it's burning.

 

[mtholton]

Does the furnace have a pilot setting and a run setting? Like a regular house furnace you start it on pilot and switch over after it's burning.

Yes, it has a pilot that you let run for 30 seconds or so, that turn the dial and the flame comes on. I can run it on the lowest setting, but if I turn it up any higher it flames out...

 

[Telemark]

Does it have a sensor?

 

[Mtyhunter]

the thermocouple should not be the issue, as it does fire up. Does sound like a pressure issue, and with the right tool, is easy to check and adjust to specs. Most regulators are adjustable. I'd start there for sure. Sometimes issues that appear to be pressure related can also be exhaust related. If there are mud dauber nests inside, and they inhibit the flow of the exhaust, it can and will do exactly what yours is doing. This is pretty common in the RV world with furnaces. You can run a boroscope into the exhaust to check for mud dauber nests. Also, on RV furnaces, there's a very small switch (sail switch) with a flapper on it, inside the exhaust tube. When the blower blows the air, the airflow pushes on the flapper, closing the sail switch. the unit needs to know the exhaust is venting correctly, to keep the unit from overheating and catching fire. They didn't mention this in the troubleshooting, but, every lp furnace i've ever seen has some sort of exhaust sensor as a safety device.

 

[Bill]

What Mtyhunter said. You put a jumper wire to the two wire going to the exhaust sensor and see if it works. Just don’t run it that way long without knowing why the sensor is tripping. I had a blocked chimney once. Sensor told me so.

 

[mtholton]

the thermocouple should not be the issue, as it does fire up. Does sound like a pressure issue, and with the right tool, is easy to check and adjust to specs. Most regulators are adjustable. I'd start there for sure. Sometimes issues that appear to be pressure related can also be exhaust related. If there are mud dauber nests inside, and they inhibit the flow of the exhaust, it can and will do exactly what yours is doing. This is pretty common in the RV world with furnaces. You can run a boroscope into the exhaust to check for mud dauber nests. Also, on RV furnaces, there's a very small switch (sail switch) with a flapper on it, inside the exhaust tube. When the blower blows the air, the airflow pushes on the flapper, closing the sail switch. the unit needs to know the exhaust is venting correctly, to keep the unit from overheating and catching fire. They didn't mention this in the troubleshooting, but, every lp furnace i've ever seen has some sort of exhaust sensor as a safety device.

Thank you will double check this! You seem to be close to earning some beer hopefully!!!

 

[mtholton]

What Mtyhunter said. You put a jumper wire to the two wire going to the exhaust sensor and see if it works. Just don’t run it that way long without knowing why the sensor is tripping. I had a blocked chimney once. Sensor told me so.

Thank you!

 

[Buckly]

Yes, it has a pilot that you let run for 30 seconds or so, that turn the dial and the flame comes on. I can run it on the lowest setting, but if I turn it up any higher it flames out...

They’re only so many parts. Maybe it’s a bad gas valve. If me, I would try and talk them into a replacement under warranty.

 

[Mtyhunter]

What Mtyhunter said. You put a jumper wire to the two wire going to the exhaust sensor and see if it works. Just don’t run it that way long without knowing why the sensor is tripping. I had a blocked chimney once. Sensor told me so.

He's right, the sail switch has only 2 wires, and the switch has to be closed for everything to operate. Jumper the 2 wires together to simulate closing the switch. And like Bill said, if it does work, don't run it for too long until you figure out why it's not closing. These switches are very small and delicate enough that dog hair or a piece of lint can jam it up.

 

[Peeps]

After holding the pilot switch down for 30 seconds or so (45) hit the igniter. Keep holding down the pilot light switch for another 20 seconds while it is already lit then turn the dial up. On ours if we go to turn the dial up rt away after the pilot lights it will go out. Ours seems to run better off of 30 lb tanks too for some reason.

 

[SD51555]

Try a 40 or 100 lb cylinder if you can get one easy enough . You may just be running into vaporization problems with a 20 lb tank. You're very close to not being able to generate enough vapor if it gets cold and your liquid level drops.



A bigger tank with more liquid produces better vaporization. Here's how it changes in a 100 lb cylinder as the quantity of gas you have decreases. Sounds fishy that you'd have a plugged orifice after a year. And everything runs on 11" WC. That 14 stuff is BS.

 

[SD51555]

Found it. I think you're starving the unit for gas on a 20 pounder. We used to have a hell of a time keeping a 15000 BTU furnace on a 20 pounder going when ice fishing. Same problem would come up. Couldn't keep it lit as the tank level dropped.

Modelo Especial or Crown Peach. PM me if you want my address.

 

[bigboreblr]

MAy be having a flow thing. Pressure and flow are generally inverse. More you push, the lower the pressure gets.

Get the 20lb tank warmer. Put it in a bucket of hot water. As poprane evaporates to gas, the tank gets cold. It's a trick I have used to push refrigerant into a system faster.

PRopane regulator? We all got a few. Steal one from a BBQ and try that. Not many propane regulators are adjustanble.

UP at camp we have had to "soak" regulators in denatured alochol. They get filled with water. Make sure you have a cover over the regulator. Often, these regulators get hit hard with rains on sides of buildings.

The pilot opens up fuel flow, if your pressure gets low, it could be lossing the pilot valves ability to open up.

Pilot could be weak, thermocouple. Some thermocuoples are not thermocouples. The convert heat into a gas pressure. That hot bulb creates pressure to open the pilot valve.