Ongoing problem with 30K btu radiant LP wall heater. Long, Please read.

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Old 11-15-16, 03:43 PM
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Ongoing problem with 30K btu radiant LP wall heater. Long, Please read.

I posted about the problem I was having with my 30,000 btu LP raidant wall heater a couple of weeks ago, and I thought I had it solved.

History:
I have been using a DynaGlow 30,000 btu LP Radiant wall heater for about 15 years, and it always gave good service and no problems.
At the end of last heating season, I noticed that a couple of the radiant (refractory) panels were getting dirty, so I planned on cleaning the heater this fall.

I cleaned the heater, blew out the (5) radiant (refractory panels), and cleaned the dust and cat hair out of the heater.
I then lit the heater, and everything was going well until a about a week later, the heater woke me from sleep by making a roar. When I looked at the heater, the flame was travelling about 3" above the top of the radiant panels, and the heater was making a noise like it had way too much gas pressure to the burner.

After reading about the code requirements concerning gas pressure regulation, I realized that I only had one 30 year old (Rego 2403 obsolete) outside regulator (at the tank).
This regulator was being used to reduce tank pressure to 13-15" wc, and was a "shut off" type regulator that would close completely to prevent the line pressure from climbing to tank pressure when the heater was not in use.
I "assumed"....I know, I shouldn't use that word.....that the seat was leaking in the regulator, and allowing the line pressure to climb and causing the heater (when idling at pilot only) to be over pressurized.

I made two changes.
I replaced the 15 year old Dynaglow heater with a new Mr. Heater 30,000 btu LP radiant wall heater #MHVFRD30LPT. Both heaters are very similiar, and both have a final regulator inside the heater cabinet to lower the 13"wc gas pressure down to the final 3.5"wc (?) used for combustion.

I replaced the regulator at the tank (50 ft. away 5/8" K Copper line to heater) with a 2 Stage Fisher LP regulator (R232A-HBF) with output pressure of 11-13" w.c.

Everything has been working great since I started the new heater about 7 days ago. Suddenly today, it did the same exact thing as before. The heater called for heat, the gas valve opened and there was a "puff" as the gas ignited. The flames were again about 3" higher that the top of the radiant panels, and the heater was roaring.....classic over pressure...it seems to me.


Has anyone ever seen one of these heaters do this??

I checked the gas pressure at the new heater when I installed the new regulator and it was 13" WC. I borrowed a WC gage, but tomorrow I'm gonna build a u-tube manometer so that I can check the pressure closely.

I'm losing confidence, and there are not any really qualified Gas Heater repairmen (anyone I can trust) around my area.

Any response is appreciated.
 
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Old 11-15-16, 03:53 PM
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You checked the pressure external to the heater but not at the heater's own regulator.
That would probably be next.
 
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Old 11-15-16, 03:56 PM
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Many GOOD propane suppliers will service appliances for which they sell propane. Have you tried that?
 
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Old 11-16-16, 08:38 AM
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I noticed you said the appliance pressure was 3.5". This is normally the pressure for natural gas. I realize some newer propane furnaces are equipped to use 3.5" instead of the higher pressure. You may want to verify you actual purchased a propane unit
 
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Old 11-16-16, 09:25 AM
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I definitely bought and received a heater set up for LP gas.
I don't know that the appliance pressure (after the internal Heater regulator) is 3.5" wc.
I used to work on large industrial gas heaters, both natural and LP, and I remember that LP pressures were usually regulated to 40% of Natural Gas pressures, due to the increased heat available in LP gas per cubic ft....roughly 2 1/2 times the Btu content.
Natural gas has 1000btu/cub. ft. while LP had 2500/cub ft.
I assumed (that word again) that these residential heaters were the same. I can't imagine running 11"wc LP gas pressure to the burner orifice on a heater, and I intend to confirm that.
I'm gonna remove the front cover on the new Mr. Heater and check the gas pressure before and after the regulator that is supplied with the heater.

With this being a random event....works great for a week or more, and then suddenly acts up....I suspect a problem with the final stage regulator, although with me supplying 11"wc to the heater, I don't see how much difference the regulator on the heater can make if it's regulating 11" wc output itself.

Does anyone know if these small, heater supplied regulators are "Lock Up" type regulators?

thanks for the response.

ps, I don't know of any gas LP gas companies around me that I would trust to work on my heater.
 
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Old 11-16-16, 10:34 AM
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Check the rating plate on the heater, it will tell the manifold pressure
 
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Old 11-17-16, 09:00 AM
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The plate on the new Mr. Heater calls for 11-14"wc supply pressure to the heater.
I checked the pressure at the outlet end of the tank regulator with a U-Tube Manometer yesterday and the pressure is steady at 13" wc.
This is a new 2 stage regulator rated for LP.
It is approx. 60 feet from the tank to the heater and the supply line is 5/8" K Copper tubing.
Today, I'm gonna check the final stage pressure at the outlet of the Mr. Heater regulator...the pressure to the orifice.
I'm also going to open both ends of the Copper gas line, tie a sock on one end, blow it out with air and see what comes out.
I'm running out of things to check.
If this doesn't fix it, I'm gonna return the Mr. Heater and try another.
 
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Old 12-29-16, 09:02 AM
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I have the same exact heater with same exact setup. Mine does the same thing about once a night. Did you ever find a cause for this? I too am about to return the heater. Thanks for any ideas.
 
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