Alde 3010 heating well but making an odd sound while in use

JP2558

Our 2018 320-CS has the Alde 3010 which is heating the cabin and water very well, but on our last two trips it began making an odd sound while in use. I'm not sure how to describe it but I'd say it's a mechanical 'clunk' that lasts about one second, and occurs I belive during the circulation process. The only thing I can come up with is that perhaps there is some sort of old style thermostat that expands or contracts due to the temperature of the transfer fluid? This past weekend we had it using both propane and electricity - perhaps it is related to only one source, but I guess the only way to test it would be to run it on propane and see if I can recreate the noise, and then repeat the process using electric only. Anyone have any ideas about what may be going on here?

pthomas745

There are just a couple of moving parts.  The circulation pump..which would seem to be to small to cause a "clunk".  The exhaust fan, when the unit starts up, it big enough to cause something, but the unit is very sensitive to the fan coming up to speed quickly, and would probably send out an error.  In the old "Alde freight train" days, the exhaust pipe going out the side of the trailer could vibrate enough to make noise all by itself. It would be easy to check to see if it has worked loose from however it is connected to the trailer.

You mention a "thermostat": there is the "automatic air bleed" device, that brass item connected to the side of the Alde.  I don't know exactly when it "kicks in", but there is a moving valve in that device that might make a noise.  There have been reports of them getting stuck...and needing an a "hit it with a screwdriver handle" to make it work properly.

JP2558

@pthomas745 Thank you for the input. The circulation is set to Therm and the pump is set to 2 and that has never been changed. The exhaust fitting is solid on the outside and does not appear to be loose on the inside. While in there I did tap on the brass bleeder several times. This weekend when it gets colder I am going to try heating first with propane only and see what happens. Then on the next night I will try it with electric only to see if there is any different behavior.

MuttonChops

A]  Are you sure you have the 3010 - - - Dec 2017 all builds got the 3020 model

B]  Are you using Propane or 120VAC as the heat source.

C]  What elevation (altitude) are you camping

My experience with the 3020 at elevation on propane is that the 'Freight Train' noises come and go, do not always sound the same, and do not happen at every camp site; but with a 3020 always go away if the 3020 is placed in Mountain or High(er) Altitude Mode.

Homebodyatheart

@MuttonChops I have a 2017 320S, built in late 2016 and have the Alde 3010. I haven’t ever heard a clunk. I also camped above 7000’ in Flagstaff this spring with no issues from the Alde. I never thought about high altitude issues until long after my trip. Maybe I was really lucky! 

JP2558

@MuttonChops - yes it is a 3010, and last weekend it was running on both propane and electric, and we are less than 1000 feet above sea level.

DaveAnna

Our 320 2021 made horrible noises while the heater fan was running. Turns out the exhaust pipe (corregated) is metal. Wrapped high temp electrical tape in a couple places. No more noise