Gas Appliance gurus, I need your help!

[NM_Shooter]

OK... my oven arrived today, and I dug my RV furnace out of the shed.  Here's the oven I found on ebay.  ~$180 shipped.



And here is my furnace that I got at a RV dealer going out of biz sale:



Both of these appliances have a similar connector :



(BTW... that's the finger I shot the nail through.  Healing up nicely, huh?  )

In addition to these two items, I have an RV water heater that I eventually need to hook up too.  So there will be three gas appliances.  I'm planning on a dual 30# tank setup with an RV auto-switch valve & Regulator combo.

Here's some questions...

1)  What do I need to hook all this up?  I'm going to have the appliances within 6' of the bottles.  I'd like to keep it all copper if possible.
2)  Where can I get the fittings?  Will I need a special tool to do the flares, or do the connectors take care of swaging for you?  (sort of like 1/4" water lines?  What are those fittings on the back of the appliances named?
3)  If I need special tools, where can they be found that will sell to ignorant civilian types?
4)  Would it be easier to just stick to tubing that is already flared with fittings in place and use T's?
5)  Anybody familiar with RV heaters?  Can they mount in any orientation, or do they require being flat?
6)  What is the best way to leak test this once it is together?

I'm still trying to figure out where the air inlet is for the cold air return on that heater.  I'm hoping to figure out a way to build a chase / filter in my cabinets.  I'm thinking of installing all of this stuff (heater and water heater) under the stove to keep all gas stuff close together and save cabinet space.

Out to the garage to take a hard look at the heater!  Thanks for any direction.

-f-

[ScottA]

You'll need a flaring tool for the copper. The fittings might be harder to find since they are being phased out. Try a plumbing supply store. The cold air return on the heater will be a large opening on either the top or bottom of the heater depending if it is upflow or downflow. From your pic it looks like the bottom. You'll need to build a plenum box for it to sit on. To leak test the gas spray the joints with a soap and water mixture and watch for bubbles for a few minutes. Take some pics of the heater at other angles so I can help you better figure it out.

[NM_Shooter]

Thanks Scott... here are a couple of other angles...





You're right... looks like it sucks in air from the back of the unit on the top or the very back.  Maybe it was designed to have a piece of sheet metal across the back though.  I think it wants to be sitting flat like that... it appears that the vent in the back is oriented correctly when it is laying flat. 

I plugged a couple of the outlet openings with cardbord and hooked it up to a battery.  Sure moves a lot of air.  It had better, as it draws 6.8A!!!

I can hear the gas solenoid turning on, but can't tell if the sparker is working.  It does not shut off if the flame does not come on though.  I think I saw on here that there is a replacement electrical board that I can get that will shutoff if no flame after 3 tries.

Are there hoses with fittings already attached that I can use to cobble this together?  Or am I stuck with flaring my own?

Also.. I just measured, and the stupid thing is 17.5" wide.  Wont fit between my 16" O.C. studs...    Maybe I'll find a way to put it under a window where I don't need a header for the wall.  Dang!  Looks like this is going under the sink.

[MountainDon]

I have a Ridgid brand flare tool, tubing cutter and reamer. Guess where they are?  


Yep in the tool shed up at the cabin. I can have them back here next Monday afternoon, if that's of any help. The Ridgid tool is much heavier duty than the run of the mill flare tools.

[rick91351]

Wow love that stove!!!

First dumb question I'm going to ask is that a propane stove or natural gas?  if it is regulated for natural gas you will have to change out a regulator so I have been told.  

Of course you will need some copper tubing, and some copper fittings and a couple tees.  Flaring tool, tube cutter can be had at any most any tool store or big box building supply or some auto supply houses.  You might have to wonder over to the plumbing department at the big box and no you don't have to have a license.

As far as your RV furnace I think it has to go the way it is currently sitting minus the ice chest of course.  The easiest way to check for leaks in lines is liquid detergent and some water.  Brush it on and watch for bubbles.

As far as a cold air return I doubt you are going to find one.  I think most that size will just pull air directly through the fan force it through the heat exchanger and out the duct work.  When it goes into its start cycle you will notice that the unit will blow cold air for thirty seconds to a minute that seems like a half hour.  Don't freak it is just purging the furnace of any trapped gas. Then it will do an ignition cycle.  When it lights off you should feel warm air almost instantly.

They make some twist fittings for the two large round holes on the side that you can connect a RV flex duct to.  They are available at Camping World or try your local RV repair shop.

Now on to the RV water heater.   How are you going to pressurize your water supply?  How big is your water supply?  I have had a could have been a bad experience with one that fired off when it was dry.  

[MountainDon]

I also have some bubble leak detector fluid that is non corrosive to copper. Some soaps are.


HD and Lowe's here both carry the flare nut fittings last time I looked. So did the RR True Value hardware store a year or so ago when I needed some fittings. I also have some flare nuts, maybe only one, up in the tool shed. My RV propane equipment all uses 3/8" copper tubing and flare fittings.


Depending on your bbq grill the regulator and hose may connect. If it doesn't you may be able to find an adapter.

[MountainDon]

There is no actual cold air return in the RV furnace as you would find in a home furnace.

The exhaust port will the upper one, the lower the fresh air intake or the burner. The furnace must be installed in that orientation. Be sure to screen the ducts on the outside. Mice and mud dawbers like to get inside them.

The blower motor has to run fast enough to make the "sail switch" inside the air path close. If the battery voltage is not high enough that prevents the gas valve from opening and the igniter from operating. That's where the built in 'glitch' comes into play as the blower continues to run the battery down. The motor has a double ended shaft with the blower for room air on the one end and the blower for the combustion air on the other end.

My RV has the furnace under a cabinet. There is a door with a grill in it that allows air into the furnace chamber. You could put a filter on the inside of the door if you wanted to.

I you have trouble finding the air duct connectors locally pplmotorhomes.com have them. I bought one from them a year or two back. They are unique to RV furnaces as far as I can tell.



Looks like a nice range too.

[lonelytree]

I need that oven..... perfect!!!!

Maybe even a hot water heater from an RV.

I take that all are jetted for propane too?!??!!! I believe that you can change that elbow fitting if you need to. Notice the sealant.

Great SCORE!!!

Mike

[NM_Shooter]

Does anyone make 4" insulated flex tubing? 

I went to HD this a.m. and bought a bunch of 3/8 tubing, flare fittings and a flare tool.  Heading to camping world at lunch to see if I can find adapters for the heater. 

I suspect that in the near term I will just set the heater on the floor and use that to heat the cabin for this hunt season.  I'd like to get the outlets to discharge away from the intake a little though.  I might just use 4" dryer vent for that.  I thought about just using the dryer vent and wrapping it with some insulation as well, but I want to be cautious about fire hazard near the outlets of the heater units.  Any thoughts on this?

Yes... the stove was a great score.  I looked it over hard last night and I think that it was rejected due to shipping damage at some point.  The right side of the cabinet flashing is a bit bent up.  Nothing structural, just cosmetic.  And the piezo igniter is broken, but I figured out a way to fix it so that it will work just fine.  A little bailing wire and stainless band clamps go a long way! 

I've basically stolen all my appliances.  Got two RV heaters (one 25k and one 15k) plus a RV water heater for less than $50.  Dunno if the water heater works or not, but now I have the gas plumbing to check it all out. 

I'll be firing up the heater tonight on a checkout run.  Yeeha.  If I can just keep the chill out of the cabin and keep it a little above 50 degrees it will be pure luxury!

[cordwood]

 The aluminum type of dryer vent tube should work for the fire resistant part.
As for the leak check bubble stuff, Don't use dish soap! If you read the label on most dish soap it says not to mix it with chlorine bleach! Why? Because it contains AMMONIA! Anhydrous Ammonia is used by farmers in tanks that LOOK like propane tanks but there is a difference. Ammonia is corrosive to Brass and Copper. Ammonia tanks use stainless steel fittings so the don't get eaten up. HD sells the right stuff and it will be worth it if you need to take anything apart down the road because even if the soap you use don't eat the pipe & fittings completely the surface corrosion can seize the fittings together and make them brittle and hard to reuse.
And remember to size your regulator bigger than you need. Too big not a problem, Too small and it can freeze up when you need it most!

[MountainDon]

Altitude!  I don't know why it took me this long to realize there may be altitude issues.  

Any propane appliance will be derated for altitude. For internal combustion engines a rough rule of thumb is 3% loss in engine power per 1000 feet of altitude (lower air pressure and less oxygen = less power unless it is supercharged). I assume the same rule would apply to burning any fuel, including propane appliances. I know from experience cooking takes longer and that if one forgets the high altitude adjustments for baking, the results are somewhat different than expected.    If you like really gooey brownies don't bother with the high altitude recipe changes.


I replaced the orifice in the Servel propane refrigerator with one for high altitude, 8500 feet and above.
The Norcold in the RV seems to work okay but the burner does soot up.

The cabin range (Hotpoint) had an adjustment nut for high altitude and I had to fiddle with the air adjustment in the oven. The range in the RV works okay but the oven burner needed the air low adjusted as well.

Our propane wall heater needed a high altitude orifice. When I spoke with the manufacturers service department they sent me one for free.  

The RV water heater manual makes mention of the unit being derated for high altitudes, but does not make any suggestions for specific adjustments. They say see your dealer. I have not done so yet. The water heater in the RV seems to work okay as does the one in the cabin. However, both seem to be more difficult to light than I recall at lower altitudes (with the RV.) They seem to blow their own pilot out. But, if it stays burning till I get the access door shut they'll continue to burn as long as there is propane.   This thought prompted me to contact the manufacturer by email. I'll post any response.


The RV furnace has not had a change made, and it seems to work okay.    I wonder if the forced air induction helps it?

Our Weber propane grill works okay, but it too seems to be more difficult to light. I takes longer to burn cook meat at 8800 feet though. The flame also has a little more yellow tipping than down lower.



I would think that without an orifice change, or adjustment of some kind, a propane appliance may be more likely to produce CO at higher elevations.



A regulator that has the capacity to run the appliances in a large RV will have enough capacity for the units in the cabin. A two stage is best and an auto changeover is very handy.



Note: Our Yamaha generator runs fine at 8800 feet without and sooty exhaust being noted, but I can tell it's power output is reduced. It has more trouble starting the RV A/C unit for example. For that it is best to run it with the power/fuel saver mode turned off and let it run at full speed rather than throttle up and down as the load changes.

[NM_Shooter]

Crap.  Altitude. I forgot about that too.  Good catch. 

I think the furnace will be okay as you noted.  I'll be bringing a CO monitor with me to install in the cabin this weekend.

I'll see if I can get the high altitude jets for the Amana range.

I think the water heater may be a crapshoot.  I have not had problems with my RV water heater at 10k feet, but this other unit is smaller and uses a pilot light.  We'll probably only light the pilot when we need hot water and not try to leave it burning.

Got a dual stage two bottle regulator with auto crossover.  Picked up a crapload of fittings, flaring tool and tubing. 

I think I am going to try and build the furnace and oven into a frame that will place the oven directly over the furnace.  Since the range is not deep (front to back) I think I will have room to run the ducts behind the oven and up the wall and either into the attic, or build them into the top of the cabinets for distribution out. 

Now..... where did I put that thermostat

Should be a fun night in the garage! 

[MountainDon]

We'll probably only light the pilot when we need hot water and not try to leave it burning.
 

We've hardly ever let the water heater run on the internal thermostat. That is, I leave it on pilot only all the time we are up there. You might be surprised how warm/hot the water will be on just the pilot if you are not using large volumes at a single time. If I've turned the pilot and all off when we left the cabin for a while, I may turn the burner on in the low setting just to be able to have warm/hot water within a short time rather than having to wait 12+ hours.

In the RV, the water would usually be running at or above the medium thermostat setting. The heater in the cabin, with it's extra 2 to 4 inches of pink foam insulation runs too hot to use without mixing with cold water.

We ration our shower time and water use so the two of us can even have showers one after the other and not have it go completely cold. That's without Karen washing her hair; that does use up more of the hot water.

If the pilot does go out the thermocouple shuts the gas flow down. But as I said once I get it going the pilot will stay lit with the door closed.


I think the furnace range idea is a good one. You could build that down here and haul the works up to the ranch.

[NM_Shooter]

Fire in the hole!

It all works.  Pshew.  But I need a better plan for the furnace.  I have to push more air than 2 4" holes, or the cutoff switch on the heat exchanger gets too hot.  How I am going to do this is a mystery to me.  My cabin is too small to accommodate much in the way of routing.  I am now considering stashing this thing in the "attic" and framing a cold air box down into the ceiling.  I am going to try and run it tonight with 4 4" holes and see how the overheating works out.  The real problem is that 25kbtu is also too big for a 280' cabin!

I can vent the thing out a gable wall above the ceiling, which will be good for keeping snow off the vent, but bad for access.

Thanks for all the advice!!!!

[rick91351]

I was a little concerned about amount of heat....  Like I wrote before, you can usually order the RV ducting from CampingWorld.com including the twist fittings for ducting to the furnace or your local RV repairman.  Another reason I like your set up is if it fails, it could be build in so it is not going to be all that hard to grab it, and take it out when you go and have it gone through.  You might want to keep a fitting or two up there where you can cap off a line if you need to.  Another thing with that stove and the oven turned on and the oven door opened slightly would certainly produce enough heat to warm the cabin and keep you from freezing.  Just not real efficient.

How about cutting a header in under an eave say in the middle of the cabin and duct both directions rather than a gable end? 



 

[MountainDon]

Suburban answered my inquiry on the water heater at high altitude.

"For High altitude operation (over 7500 ft) have burner part number 010844 installed."
That's for a 6 gallon model SW6P, recent model.

I suspect it's an orifice but now have to find out and get one.


 I should have asked them about the furnace!!!  


EDIT: yes it is an orifice.

[MountainDon]

...I have to push more air than 2 4" holes, or the cutoff switch on the heat exchanger gets too hot.  How I am going to do this is a mystery to me.  My cabin is too small to accommodate much in the way of routing.  I am now considering stashing this thing in the "attic" and framing a cold air box down into the ceiling.  I am going to try and run it tonight with 4 4" holes and see how the overheating works out.  The real problem is that 25kbtu is also too big for a 280' cabin!.

Your cabin is not necessarily smaller than the RV that the furnace may have been designed for. Also where it will finally reside is more than likely to be cooler to begin with than your test chamber, the garage. 

If the overtemp switch is working the way it is supposed to it will cut the flow of propane and the blower will still run. When it cools down sufficiently the propane should be turned back on and the igniter should go into action and relight the burner. If the wall thermostat now calls for no heat the propane will not be turned on and relit, but the fan should continue to blow until the furnace is at a "safe" temperature. Our RV furnace uses three of it's four outlets and goes through a few cycles at times. The blower even restarts at times just to cool down some more after the heat soaks out of the iron heat exchanger.

If the furnace ends up being too large for the space you'll have to increase the amount of space.   

[NM_Shooter]

Okay... 4 pcs of the 4" cutouts out of the box and the overheat cutoff does not trip.  Sure brings my garage temperature up in a hurry.  Outlet temp is 150 degF.  I can't imagine this furnace ever needing to be on for more than 60 seconds in that cabin.  I may need to build my own thermostat in order to get a bit wider dead zone on the thing.   It would be nice to have it kick on at 55 and off at 65.  Although I think that the size of the burner is going to cause it to overshoot a bit.  Probably take a while to fine tune the thing.

I'm wondering about the penetration to the outside for the burner vent.  I think I'll try and relieve a hole about 1" around the vent pipes, and then build some sort of bezel sort of thing out of some sheet metal.  Having hardi plank on the outside is probably decent insurance.