2006 Furnace fan bearing noise (Hydroflame?)

[Lotus54]

I’m just starting to research this- (couldn’t find a previous post).
The fan bearing is squealing after it runs a bit. Has anyone gotten into one of those for replacement? Thought I’d ask before I spent a load of time.
I believe it is a Hyrdroflame (I’m not home at the moment)

Thanks for any ideas
Mark

[InterBlog]

The issue as described is unfamiliar to me, and I do not recall anyone else posting about it over the past 3 years.

If the heater proves to require replacement, I'd be interested in knowing what the options are. I'd pay good money not to have to hear that little frigger of a fan cranking up in the middle of the night, time after time.

Although, from what I've read, the diesel heaters can be worse where noise is concerned. I was all hot to trot for one of those newer higher-tech diesel heaters until I read the reports. The phrase "jet engine" has been used, although I can neither confirm nor deny whether the issue has been exaggerated.

[Protagonist]

Originally Posted by InterBlog

I'd pay good money not to have to hear that little frigger of a fan cranking up in the middle of the night, time after time.

If only there was a way to have the furnace fan run all the time, whether the heat is on or not, same way the a/c fan can be set to run all the time whether the a/c is cooling or not. Because the noise level difference between furnace fan and fan+heat would be a lot less disruptive than between nothing and fan+heat.

[Titus]

Hydroflame installation manual says that debris in the fan could cause it to be noisy. It also says to clean the blower annually. But no description on how to do that. Per picture it looks like the blower is towards the back, and thus you might have to pull the furnace. The exhaust pipe screwed to the side of the van is a slip fit into (or over) a larger (or smaller) pipe sticking out the back of the furnace. So I could imagine pulling the furnace out while leaving the exhaust pipe in place. But it might be tricky to get the two pipes to line up when re-installing. It says nothing about oiling the fan motor.

Regarding the noise, we don't leave the furnace on at night. In the morning the inside temperature is about 10 deg F above outside temperature - easily manageable with a sleep bag on top of our normal bedding. I turn on the furnace when we are ready to get up, and stay under the covers until the inside temperature reaches 60. (Inside propane switch and furnace thermostat are within reach by sitting up in bed.) Then I get up to make coffee while the furnace blows hot air on my feet. Then I put my shirt and pants in front of the blower to warm them up before putting them on. Ahhh. And best of all my wife thinks I am a hero for getting up first.

[cwf]

Our 1999 motor got LOUD on our first cool outing use.

I searched till I found a replacement motor. Around $35. Two hours later (first time take apart furnace) she is quiet and warm....

[InterBlog]

Sometimes I do the same, but when the temp falls as low as into the 30's, it's a pain not to have heat at night. Even with lots of bedding, I'm still sucking 40-ish degree air into my lungs, so I tend to get cold no matter what. Chilled from the inside out, instead of the outside in.

[A W Warn]

Originally Posted by Lotus54

I’m just starting to research this- (couldn’t find a previous post).
The fan bearing is squealing after it runs a bit. Has anyone gotten into one of those for replacement? Thought I’d ask before I spent a load of time.
I believe it is a Hyrdroflame (I’m not home at the moment)

Thanks for any ideas
Mark

It could be the fan is rubbing something, not a bearing at all. (hopefully)
I've taken my furnace apart to clean it. It's intimidating the first time, but pretty simple after getting into it.
The fan can get full of dust buildup and become out of balance causing it to rub the fan housing (making an intermittent squealing noise). The sail switch can get blocked with this dust and stop ignition. This video might give you an idea of what's involved.

https://www.youtube.com/watch?v=evjy3cYeAXg

[mandolindave]

Might not be very different. They don't have ball bearing type bearings.

I just took it apart and cleaned all the goop off of the shaft and " bearing ". then oiled it. ( hint...luckily I remembered how it went back together…should have taken pictures with my phone ) It was so gooped up that the motor wouldn't even spin.

But the squealing could be worn shaft ( which means a new motor is needed )

Anyway….If that doesn't work, try to replace the motor. You don't want to have to change the furnace obviously. ( My furnace was discontinued and had to do some modifications to fit the new one (yeah….EEWWW )

Waver…I could be wrong. I'm not an actor but I play one on TV.

[GM Airstream]

Having just done mine... (motor replacement) I found that they do have ball bearings on the motor shaft... but, lack a port to add some lube to keep things 'well lubed' ... What I think the guy is pointing to for noise is the motor brushes... they squeek till you get them broke in... although the air noise from the blower and all also can be heard... due to no damp'n of the air in the ducts...

As to dirt in the blowers... I found that the mud dobbers added a lot of mud to the inside of the blower assembly... and now am run'n the screens on the outside of the heater vents... to keep the little bug'rs out...

Thank goodness to the utube people who... posted a good how to take it apart and back again... along with how to rebuild the blower motor... to save the cost... most of the motors are up around 100 bux... new...

here is a pix of how the mud bugs got into mine... and made lots of noise... with the blower rubb'n...

[Titus]

I think these last few posts are furnaces in trailers with easier access than we are dealing with in the Interstate.

[GM Airstream]

Yep... but they should be the same brand and similar make... one would think...

[Protagonist]

Originally Posted by Titus

I think these last few posts are furnaces in trailers with easier access than we are dealing with in the Interstate.

Originally Posted by GM Airstream

Yep... but they should be the same brand and similar make... one would think...

When the only access to the furnace is from an aisle that is only about 20" wide as in the Interstate, even an otherwise simple task becomes problematical.

[GETRIDAONE]

All the bees in the furnace got me looking at screens. The main one seems to be a Camco that attaches with a spring and doesn't stay long before the spring breaks. I found these drain strainers at Wal-Mart and decided to try it. I would have liked stainless but the aluminum should be OK. I had to drill a hole in the center of the bottom intake, the top exhaust already had a hole punched. I used SS screws to attach them. For an investment of $3.00 I may avoid a potential problem later. It doesn't seem to restrict the exhaust coming out.

[dznf0g]

Originally Posted by GETRIDAONE

All the bees in the furnace got me looking at screens. The main one seems to be a Camco that attaches with a spring and doesn't stay long before the spring breaks. I found these drain strainers at Wal-Mart and decided to try it. I would have liked stainless but the aluminum should be OK. I had to drill a hole in the center of the bottom intake, the top exhaust already had a hole punched. I used SS screws to attach them. For an investment of $3.00 I may avoid a potential problem later. It doesn't seem to restrict the exhaust coming out.

Be VERY careful. At first glance, it appears to me that there is a substantial flow restriction with those "strainers". You must have no less than the opening pipe area available for unrestricted exhaust and intake. You may be overheating your heat exchanger...or not allowing the sail switch to ignite at all. I would remove those now.

[GETRIDAONE]

The larger dome shaped perforated screen actually has 20% more free area than the exhaust hole its self. If it were flat and the same diameter it would restrict the flow by 65 %

[dznf0g]

Originally Posted by GETRIDAONE

The larger dome shaped perforated screen actually has 20% more free area than the exhaust hole its self. If it were flat and the same diameter it would restrict the flow by 65 %

As long as you did the math! But, the metal area between the holes still creates turbulence and offers resistance to flow...I am not sure how to do the math on that issue. I just went through this exercise with my stick house high efficiency furnace intake/vent pipes.

[Titus]

Be careful with an analysis of the hole area. There is far less flow through many small holes of the same area as one large hole, due to the 'wall effect'.
Bare with me on the technical details: The velocity of the air through the hole is zero at the edge of the hole and increases to a maximum as you get to the middle of the hole. The many small holes have a lot of 'edges' with zero flow and not as much center area with high flow. I would guess that even though your strainers have 20% more free area, they have much less total flow.

A couple of ways you could test this:
1) Measure pressure inside the exhaust pipe with and without the strainer in place. Not sure if there is an easy way to get a water manometer probe inside the exhaust pipe. Higher pressure with the strainer in place means less flow.

2) Measure temperature coming out. Higher temperature is probably an indication of less flow.

If you are worried about bugs getting in, you could cover the exhaust port while the AI is not in use. The vast majority of the time the AI is not being used, and this is most likely when the insects are building their nests.

[dznf0g]

Originally Posted by Titus

Be careful with an analysis of the hole area. There is far less flow through many small holes of the same area as one large hole, due to the 'wall effect'.
Bare with me on the technical details: The velocity of the air through the hole is zero at the edge of the hole and increases to a maximum as you get to the middle of the hole. The many small holes have a lot of 'edges' with zero flow and not as much center area with high flow. I would guess that even though your strainers have 20% more free area, they have much less total flow.

A couple of ways you could test this:
1) Measure pressure inside the exhaust pipe with and without the strainer in place. Not sure if there is an easy way to get a water manometer probe inside the exhaust pipe. Higher pressure with the strainer in place means less flow.

2) Measure temperature coming out. Higher temperature is probably an indication of less flow.

If you are worried about bugs getting in, you could cover the exhaust port while the AI is not in use. The vast majority of the time the AI is not being used, and this is most likely when the insects are building their nests.

Yeah, that's a much better explanation of what I was trying to say. If you are stuck on using these covers (and they do look nice) you might drill out each hole. It seems there is a lot of meat to work with....but I wouldn't ignore Titus' points and methodology.

[Landozoor]

Originally Posted by GM Airstream

......
here is a pix of how the mud bugs got into mine... and made lots of noise... with the blower rubb'n...

I had to dismantle my heater too.
I discovered that kind of thing.
This is made in USA ! !

I found a nest of wasp.
Much more common for me.

I'm thinking to temporarily obstruct when not used.
I do not know yet how. But I think it's obligatory.

[GETRIDAONE]

OK temperature testing is complete.

Screens in place outside at center of screw holding screen 180
No Screens outside at center of cross support 191

Inside grille measured at center of supply 235 > 250
Inside was about the same (screen on or off )

I think the aluminum screen acted as a heat sink on the 11 degree difference of outside temperature.
The velocity of the exhaust is hindered by the screen and kind of rolled up the side instead of being blown out and away.

Conclusion: l will leave the exhaust screen off, keep the intake and not stand to close to the very hot supply grille.