Furnace in our Heartland sounds like a foghorn when lighting

[Mr__Black]

Since new our fifth wheel has been very obnoxious when the furnace lights off. It makes this unusual tuba sound when it first lights. It often wont light off on the first try so you get to hear the tuba sound two or three times. Once lit fully the sound goes away and it sounds like a normal furnace.

This sound is loud enough that I have actually had other people comment on it and has me wondering if we are inadvertently waking neighbors up in the middle of the night.

Trailer is a 2011 Heartland Sundance. Furnace I believe is a Suburban SF-30. I've had this furnace before in other trailers and it never made this noise.

The trailer is at the dealer right now for this and other warranty issues. I am going to pick it up today and I just have a hunch that it's still going to make this noise.

To add insult to injury, my folks also have a 2011 Heartland Big Country and their furnace makes this same god awful noise. Commonality? maybe something in the propane regulator they're using?

Anyone else run into this?

[sljkansas]

X2 on the mud daubers, cost me around $500 for repairs on the water heater due to them. I had screens on all the lovers but one, it was the smaller louver on the left side of the access panel. New circuit board, gas relay, wiring and labor. I had the local mobile RV service do the work, and was very pleased with them. (Cost wasn't very nice but all is working)

I went to my local RV parts store looking for a screen to cover that one louver and low and behold, there it was the correct screen to cover it. You have to drill a 1/16th hole in one of the louvers to fasten the spring. when I took it to the counter to pay for it, the lady said they just got them in, and they were the first ones they had seen for that louver. I'll have to find the package info to remember you makes it.

[eHoefler]

Check for a blockage in the heat exchanger, like a mud dauber nest

[RoyB]

If mine doesn't fire off on the first try then it shoots out a very large flame from the side of the trailer when it does finally fire-up... Kinda scary when you see it for the first time... This gives off a loud WHOOOMP sound...

Roy Ken