suburban furnace repair. (B1700)

[Herb P]

When I bought the trailer, the PO said "oh, we never used the furnace", which everyone knows is "weasel speak" for "the furnace is broken but I don't want to tell you that". There was clear evidence that the furnace had been used since the brass handle on the shutoff valve was not as tarnished as the rest of the valve, and the pilot 'reset' button was nice and shiny where one would put their finger... I persisted and managed to get the pilot lit pre-sale. But it took darn near 30 minutes to do. The pilot just wasn't catching or when it did, was a tiny limp flame.

Our first camping trip, the furnace performed admirably after spending 30+ minutes trying to get the pilot to light and stay lit. Good thing too, because it snowed that night.

Second camping trip I got the pilot to light after much persistance but unbeknownst to me, it went out early in the night and we had a chilly (but not uncomfortable sleep)...

Last camping trip, I could not get it to light _at_all_... No way, no how...

We're going next week, it's starting to get cooler at night in the mountains, so I wanted to make sure we had the option of heat, if we need it.

So I removed the furnace from the trailer, stuck it up on my workbench, pulled it out of its sheet metal shroud, and started analysing... I confirmed the thermocouple was good because I could heat it up with my lighter and hear clicking both on the heat-up and cool-down... I grabbed my old and spare Boler propane regulator and along with some other fittings, hooked a 20lb propane tank up to the furnace on my workbench. I removed the pilot 'tube' from the "controller" at the back of the furnace, pushed the pilot reset button, and heard the comfortable hiss of propane... So I worked forward toward the pilot orifice. There was no cloggage in the tube as it entered the pilot orifice so I concluded the pilot orifice was clogged. I removed it and looked, and could see where there should be a teeny tiny hole, but the hole seemed plugged... I couldn't find a pin or anything small enough to fit in the hole, so figured I'd have to buy a new orifice. On a lark, I threw it in my ultrasonic washer with some brakleen (dry cleaning fluid) for 15 minutes... After I took it out and dried it off, I was able to look through the orifice and a few photons got through the hole to my retina...

Reassembled the furnace and voila! The pilot lights instantly!

This was surprisingly little effort overall. I don't know if these orifices (orifii?) are common off the shelf items or not.

[Dan M.]

I've used a single strand of fine stranded copper wire to clean an orfice. The copper is also soft and won't damage the orfice.

[BobB]

Congratulations, Herb! You seem to have a lot of patience.

[KevinDR]

Impressive. And who said you didn't have talent?




I will mark this one down when my old furnace starts to give out. Do you make service calls?

[Benny K]

I hadn`t used my furnace in a couple years and it worked fine when I last used it but yesterday I tried it and the pilot wouldn't lite, so when I get a chance, I`ll have a starting point...thanks..... Benny

[Gerry]

Great job Herb but don't be discouraged if in a few months somethinge else will go wrong.
Like Benny, after buying all new parts from regulator to pilot and thermo-couplin, even blowing out lines, last May, and having an A1 job done
Getting ready for a late Sept week in the northern woods of Maine better try it out and Nope no combustion.
After an hour of adjusting it was to the RV shop...First time I let someone else work on it since I got it.
I think that was a mistake because yesterday after it was 2 days in the shop I went down and talked to machanic and he told me he had it out of the trailer twice and it worked fine on bench but inside trailer it wouldn't light.
After he told me the furnace grounds were not good,(Fan and ground of fuse) or I should say sometimes working and sometimes not I was alittle upset.
Upset because they always worked when I turned it on before I brought it down there.
I imagine the labor cost will be astronomical to have this little job done.
I feel a shop expert should have known and fixed this problem just from the way it ran or didn't run, and not have to pay for his lesson of working on an older duo-therm.
Gerry the canoebuilder

[Herb P]

That does sound annoying... Looking in the Suburban model, it looks like the upper models have all sorts of interlocks and safeties, etc... Even the basic model in my boler has a few.. So if you have anything newer, it probably has lots of auto-ignition, don't turn on the gas until the fan is up to speed, don't turn anything off till it cools down, blah blah blah interlocks ... At which point, I might also run out of patience... My wife's truck won't let you shift out of park if one of the brake light bulbs is blown... I agree, that sort of knowledge is what you're paying shop rates for ...

I'm considering getting a small ceramic space heater for this trip, just in case my furnace repair doesn't stick... Anyone have any experience with quiet but effective space heaters? We're going to have electricity where we're going next week.

[Brian B-P]

... Anyone have any experience with quiet but effective space heaters?

Given what is in an electric space heater, it's hard to go wrong.

We have one which has a variable-speed fan, which is nice because it is only as loud as it needs to be. I have no idea of the brand, and it probably doesn't matter anymore as it is about 15 to 20 years old. We found it heated the B1700 quite adequately in approximately freezing (zero Celsius) overnight temperatures, although of course it was somewhat uneven with the heat source at one spot on the floor.

[Herb P]

Given what is in an electric space heater, it's hard to go wrong.

We have one which has a variable-speed fan, which is nice because it is only as loud as it needs to be. I have no idea of the brand, and it probably doesn't matter anymore as it is about 15 to 20 years old. We found it heated the B1700 quite adequately in approximately freezing (zero Celsius) overnight temperatures, although of course it was somewhat uneven with the heat source at one spot on the floor.

Guess I'll make use of that Canadian Tire coupon tomorrow...

[Pete Dumbleton]

That does sound annoying... Looking in the Suburban model, it looks like the upper models have all sorts of interlocks and safeties, etc... Even the basic model in my boler has a few.. So if you have anything newer, it probably has lots of auto-ignition, don't turn on the gas until the fan is up to speed, don't turn anything off till it cools down, blah blah blah interlocks ... At which point, I might also run out of patience... My wife's truck won't let you shift out of park if one of the brake light bulbs is blown...

I'm normally kind of a safety guy, but the number of safety systems in the typical modern RV furnace means they are not likely to work when you need one. I prefer one of the unvented heaters like an Olympian if you want permanent mount or a Mr Heater or Coleman Cat if you like portable (take it along to the outhouse...). They add some condensation to the air, but we have to deal with condensation anyway.

AFAIK, the best heat is electric when you have the hookup. I carry an electric heater in addition to my unvented heater.

Hmm, so if some attacker wants to stop your wife from driving off after she locks herself in the truck, all he has to do is kick a tail light fixture before she can get it started and shifted? Sounds like an "improvement" that needs further improvement...

[Herb P]

Hmm, so if some attacker wants to stop your wife from driving off after she locks herself in the truck, all he has to do is kick a tail light fixture before she can get it started and shifted? Sounds like an "improvement" that needs further improvement...

Not quite as nefarious but that's close to what happened... My wife called me at work to tell me she was at <some girly shopping place> and couldn't get the truck out of park... I, being at my place of gainful employ, wasn't quite sure what exactly I could offer except my heart-felt condolences (a sentiment for which I later paid dearly) when it occurred to me that I could invoke the mighty powers of the knower-of-all-things: Google... Alas, there is, on the shifter, a small portal into the deeply guarded nether regions of the vehicle into which a hapless housewife could thrust a mighty ballpoint spear while simultaneously pulling back on the shifter in order to free herself from the confines of the soul-sucking mall.

[Pete Dumbleton]

Har!! I suggest something suitable for the purpose (that won't disappear like a pen might) be hung by a small chain from the dash or column for the express purpose of hitting the "reset" button