Hydro flame LB-11L furnace?

[Kxracer704]

Originally Posted by TheHunter

Thank you!!! I suspected that LoL. I was thinking of options to stop that leak, jb weld was my thought, not sure how much heat that spot gets though. I was sure hoping to find us a shiny new pilot and couple but it's becoming obvious it's just not possible. My next step is going to be to fab up something using the 3 other thermocouples I bought to try, all the newer style couples have a different thread size going into valve or maybe a New valve would probably cure that and then I think fabing something up would be real easy

I don’t think jb weld will hold up. That area gets hotter than 500F I’m pretty sure. The stove cement I used is made by Imperial and I believe is rated to 2000F. You should be able to buy it at hardware stores and Lowe’s.

[TheHunter]

Originally Posted by Kxracer704

I don’t think jb weld will hold up. That area gets hotter than 500F I’m pretty sure. The stove cement I used is made by Imperial and I believe is rated to 2000F. You should be able to buy it at hardware stores and Lowe’s.

The temperature in that area I was unsure of, I'll go with your known method and be done. Thanks again and Merry Christmas

[Kxracer704]

Your welcome! Merry Christmas!

[TheHunter]

Is this how yours looked

[TheHunter]

Originally Posted by Kxracer704

Your welcome! Merry Christmas!

Arrow pointing too where it's leaking out below pilot, actually I thought it was leaking lower than that but hard to tell till I pulled it out and lite it. Is this how yours looked before sealing it

[Kxracer704]

Originally Posted by TheHunter

Arrow pointing too where it's leaking out below pilot, actually I thought it was leaking lower than that but hard to tell till I pulled it out and lite it. Is this how yours looked before sealing it

Mine leaked just below where the red arrow is, just above the small flat steel plate that screws into the flame box.
I’m now second guessing if my pilot is correct because I see how aggressive your pilot flame is. My flame is much tamer, but I believe this is one of my issues with my furnace because I’m having a symptom of late ignition of the main burner when the furnace kicks on. This may be due to the small pilot light that I have.

On my gas valve I have a screw that is labeling “pilot adjust”. I have removed the o ring cap and turned this screw in and out but have not had any luck with it changing the pilot flame size. Do you have this adjustment screw and if so does it indeed adjust your pilot flame size?

Thanks,
Jay

[TheHunter]

Originally Posted by Kxracer704

Mine leaked just below where the red arrow is, just above the small flat steel plate that screws into the flame box.
I’m now second guessing if my pilot is correct because I see how aggressive your pilot flame is. My flame is much tamer, but I believe this is one of my issues with my furnace because I’m having a symptom of late ignition of the main burner when the furnace kicks on. This may be due to the small pilot light that I have.

On my gas valve I have a screw that is labeling “pilot adjust”. I have removed the o ring cap and turned this screw in and out but have not had any luck with it changing the pilot flame size. Do you have this adjustment screw and if so does it indeed adjust your pilot flame size?

Thanks,
Jay

I coulda swore mine was also leaking where your saying but after I removed it and lite it I couldn't get nothing but where I was showing there.

Mine does have a adjustment and I was considering turning it down a little, I think it's way over what's needed but I guess no way it could ever go out like it is LoL. I put cement around where my arrow is pointing but it hasn't dried yet and I'm waiting on my gasket material which should be here anytime, after that I'll try again and let you know how the adjustment goes. FYI I read clock wise for smaller and CCW for larger flame

I did fill that orfice with alcohol many times while blowing air thru and that helped alot as the first time lighting you could barely see the pilot flame

[Kxracer704]

Originally Posted by TheHunter

I coulda swore mine was also leaking where your saying but after I removed it and lite it I couldn't get nothing but where I was showing there.

Mine does have a adjustment and I was considering turning it down a little, I think it's way over what's needed but I guess no way it could ever go out like it is LoL. I put cement around where my arrow is pointing but it hasn't dried yet and I'm waiting on my gasket material which should be here anytime, after that I'll try again and let you know how the adjustment goes. FYI I read clock wise for smaller and CCW for larger flame

I did fill that orfice with alcohol many times while blowing air thru and that helped alot as the first time lighting you could barely see the pilot flame

If you used the same cement I recommended in an earlier post, definitely let it cure fully. I was impatient and it burned a pin hole thru the first coat of cement I applied. I applied a second coat of cement and that seemed to seal it up. I also noticed that the pilot burns slightly different once you have it in the flame box with the door shut, so that’s maybe why it’s burning different for you when you took out the assembly and lit it on the bench.

I do not get any pilot flame adjustment when I turn the pilot adjustment screw so I think my pilot orifice is clogged. I never removed it and cleaned it because I was nervous to break one of the parts. And because (as of now) cannot find a new thermopile assembly, I’m hesitant to dissemble and clean. But it’s not working correct, so I think I’ll try and clean it out.

[TheHunter]

Originally Posted by Kxracer704

If you used the same cement I recommended in an earlier post, definitely let it cure fully. I was impatient and it burned a pin hole thru the first coat of cement I applied. I applied a second coat of cement and that seemed to seal it up. I also noticed that the pilot burns slightly different once you have it in the flame box with the door shut, so that’s maybe why it’s burning different for you when you took out the assembly and lit it on the bench.

I do not get any pilot flame adjustment when I turn the pilot adjustment screw so I think my pilot orifice is clogged. I never removed it and cleaned it because I was nervous to break one of the parts. And because (as of now) cannot find a new thermopile assembly, I’m hesitant to dissemble and clean. But it’s not working correct, so I think I’ll try and clean it out.

Different brand but same stuff cement. Directions say atleast 24hr to cure so I guess tomorrow afternoon I'll give it a go.
Yeah I was afraid to try and remove the orifice so I just blew thru the fitting etc with the line off and everything complete, it helped for sure.

[Kxracer704]

Originally Posted by TheHunter

Different brand but same stuff cement. Directions say atleast 24hr to cure so I guess tomorrow afternoon I'll give it a go.
Yeah I was afraid to try and remove the orifice so I just blew thru the fitting etc with the line off and everything complete, it helped for sure.

Ok. Did you squirt the alcohol and blow the air from the line end or the pilot flame end?

[TheHunter]

Originally Posted by Kxracer704

Ok. Did you squirt the alcohol and blow the air from the line end or the pilot flame end?

Actually both. I pulled the thermo pile out and that pilot hood top half of mine came off once I bent the 2 little tabs on the bottom a little. Mine was already loose so it wasn't a big deal, if yours is tight then I don't know if messing with it is a good ideal LoL

Where red is came apart

[Kxracer704]

Ok I removed the hard line that feeds the pilot gas from the gas valve. It was clear of debris. I then removed the jet orifice and rust crumbles and dust fell out when I removed it. I soaked it in denatured alcohol and squirted alcohol thru the orifice. It was a solid stream and cleared out. I reinstalled everything. I'm sure the rust was interfering with the orifice. The positive is now I can adjust the pilot screw and the flame does get smaller or bigger. The negative is I am still having problems with the late ignition of the main gas burner which causes a mini explosion in the flame box almost time the furnace kicks on. The odd thing is that the explosion is intermittent and sometimes kicks on smooth like it should.

Also now that I can adjust the pilot flame I was playing with the settings and I cannot get my pilot flame to be as blue or aggressive as yours in your photo. when I increase the flame size it turns yellow at the top like a bic lighter. I don't know if this matters, but what is the gas pressure you are feeding your heater?

[TheHunter]

Originally Posted by Kxracer704

Ok I removed the hard line that feeds the pilot gas from the gas valve. It was clear of debris. I then removed the jet orifice and rust crumbles and dust fell out when I removed it. I soaked it in denatured alcohol and squirted alcohol thru the orifice. It was a solid stream and cleared out. I reinstalled everything. I'm sure the rust was interfering with the orifice. The positive is now I can adjust the pilot screw and the flame does get smaller or bigger. The negative is I am still having problems with the late ignition of the main gas burner which causes a mini explosion in the flame box almost time the furnace kicks on. The odd thing is that the explosion is intermittent and sometimes kicks on smooth like it should.

Also now that I can adjust the pilot flame I was playing with the settings and I cannot get my pilot flame to be as blue or aggressive as yours in your photo. when I increase the flame size it turns yellow at the top like a bic lighter. I don't know if this matters, but what is the gas pressure you are feeding your heater?

I'll check my regulator later today for some pressure numbers but it looks like a standard gas grill type regulator.

Have you tried a different propane bottle, I've heard of dirty propane gas happening.

Also while I was cleaning out everything the first time thru I was lightly tapping on the main burner and blowing air thru and got quite Abit of dirt and crap out of it too. It sounds like yours is clogged which is causing the slow propane delivery and explosion, hopefully that's the issue and not something in the valve though I did see similar valves to ours and price wise wasn't to bad $60-70

[Kxracer704]

Originally Posted by TheHunter

I'll check my regulator later today for some pressure numbers but it looks like a standard gas grill type regulator.

Have you tried a different propane bottle, I've heard of dirty propane gas happening.

Also while I was cleaning out everything the first time thru I was lightly tapping on the main burner and blowing air thru and got quite Abit of dirt and crap out of it too. It sounds like yours is clogged which is causing the slow propane delivery and explosion, hopefully that's the issue and not something in the valve though I did see similar valves to ours and price wise wasn't to bad $60-70

Ok yeah I may have to disassemble again and check if the main burner is clogged. I definitely can hear the gas flowing, but it may still be clogged slightly. Let us know if you get that pilot light back assembled and functioning again!

Also I have tried different propane tanks, all had same symptom. And I have a new regulator that is supposed to be set at 11” W.C. pressure.

[JohnB]

Originally Posted by TheHunter

I'll check my regulator later today for some pressure numbers but it looks like a standard gas grill type regulator.

Hi,

Just a friendly heads up, LP gas appliances that are indoors are low pressure appliances which run on 11" WC (water column). 11" WC is around 0.5 psi. This is a LP safety thing, home furnaces, dryers, water heaters, ranges, and campers for indoor appliances etc.

Outdoors LP gas stoves, grills, etc. are often high pressure devices, which can be 7 to 10 psi depending on brand, make etc.

Your camper should have a low pressure regulator 11" WC. Some of the older camper regulators, "looked" like a standard grill type regulator but are not. The newer regulators are 2 stage, first stage takes main tank pressure which can be 150psi or higher pending temperatures down to a normal LP high pressure, 5 to 10 psi, then the 2nd stage takes it down to 11" WC for a more accurate control. If one accidently hooks up a 5 to 10 psi gas supply to appliances rated at 11" WC, the diaphragms in the gas valves, gas hoses etc. can rupture from overpressures. Plus the unit can overheat fast as too much gas comes through due the high pressure.

Just passing the learning along so you do not make a mistake unintentionally.

Hope this helps,

John

[JohnB]

Hi,

I have never worked on one of the old furnaces in your post. I'm following along, learning with you.

One thing noticed, these old hydroflame units were the onset of the basics in furnace control and really lack a lot of the newer safety features. The newer next generation furnaces have a heat exchanger and double blower for purging before ignition, overtemp sensor shut down, air vane sensor shut down if not enough air is blowing, a new flame sense system with electronic ignition, double solenoid gas valves to name a few.

Popups campers had a Hydroflame 7900/8012 series furnace with all the new safety feature upgrades and blower forced heat from a heat exchanger. I worked on some of them. They were small and had a front grill for the heat discharge into the camper. I tried looking for them to see if that could be an option for older truck campers. Well, Atwood was bought out by Dometic a few years back and it seems they Dometic discontinued the 7900/8012 series. Parts are still around, but not the furnace packaged like that. Dometic does make smaller furnaces, just they are packaged bigger and not sure they offer a ductless unit. See here , expand it to ALL models they make a 12K btu unit. https://www.dometic.com/en-us/us/pro...ns/rv-furnaces

The other good RV furnace is Suburban. They still have a comparable unit like the 7900 series, they call it the NT-SEQ model https://www.airxcel.com/rv/suburban/...ies-medium-rvs

They have 16 000 & 19,000 BTU ratings with ducted or non ducted.

Doing some quick searching, the NT-16SEQ is about $550 and sometimes free shipping and sometimes not.

Here is 2 hits on the web for them.
https://www.ebay.com/i/133540875126?...BoCafoQAvD_BwE

https://www.adventurerv.net/suburban..._source=google


Something to think though as you try and sort out what you have.


Hope this helps.

John

[TheHunter]

Ok so I got it all back together and other than it seems to take forever to get that thermopile warmed up the furnace seems to work great. Not near as aggressive pilot flame now that it's sealed up but it's still nice and blue.

The valve is a Marshall model#230 and from the 2 sites I looked at it's set at 11" wc

Obviously it gets hot but what is too hot? I was getting some nasty burn off smell, not wood thankfully even though I cleaned it out but that outer furnace wall was getting pretty dang hot. I've got a laser thermometer but not sure what I should base it off of

[Kxracer704]

Originally Posted by TheHunter

Ok so I got it all back together and other than it seems to take forever to get that thermopile warmed up the furnace seems to work great. Not near as aggressive pilot flame now that it's sealed up but it's still nice and blue.

The valve is a Marshall model#230 and from the 2 sites I looked at it's set at 11" wc

Obviously it gets hot but what is too hot? I was getting some nasty burn off smell, not wood thankfully even though I cleaned it out but that outer furnace wall was getting pretty dang hot. I've got a laser thermometer but not sure what I should base it off of

I’ll run my furnace once I clean the main burner out and see how hot the outside of the flame box gets and I’ll let you know. But from memory, it gets pretty hot. I remember 500F possibly. But don’t quote me on that

[TheHunter]

Originally Posted by Kxracer704

I’ll run my furnace once I clean the main burner out and see how hot the outside of the flame box gets and I’ll let you know. But from memory, it gets pretty hot. I remember 500F possibly. But don’t quote me on that

I didn't run it long but before I shut mine down and I was 400 + so I could see 500's pretty easily.

Any ideal what temp the thermo cell kicks in at? There's no numbers on it of course and Its hard to get a laser reading up in there but it was reading over 200 and the little fan never came on. If I hold a lighter flame directly to it it'll go but so far not enough furnace heat has sat it off

[Kxracer704]

Originally Posted by TheHunter

I didn't run it long but before I shut mine down and I was 400 + so I could see 500's pretty easily.

Any ideal what temp the thermo cell kicks in at? There's no numbers on it of course and Its hard to get a laser reading up in there but it was reading over 200 and the little fan never came on. If I hold a lighter flame directly to it it'll go but so far not enough furnace heat has sat it off

The outside of my fire box maxed out my temp gun 550F+ at its hottest area. For the temp sensor, I don't know exactly what temp it kicks the fan on at but my furnace has to run for about 2 min from a cold start for the blower fan to kick on.

Originally Posted by TheHunter

Also while I was cleaning out everything the first time thru I was lightly tapping on the main burner and blowing air thru and got quite Abit of dirt and crap out of it too. It sounds like yours is clogged which is causing the slow propane delivery and explosion, hopefully that's the issue and not something in the valve though I did see similar valves to ours and price wise wasn't to bad $60-70

I took my burner assembly apart again and took the main burner orifice out. At first it looked like the hole was pretty clean and not clogged. But after soaking it in denatured alcohol and squirting alcohol thru the orifice with some pressure from a squeeze bottle it cleared out some dirt. The orifice size was probably double in size after cleaning.

I took some photos for reference with my homemade gaskets and cement patch job.

I reassembled the furnace and tested it. You were right! The main burner sounds quieter now and has a more consistent flame. And the best part is that the explosion from ignition problem is solved. Thanks again for the tips!