Honeywell Motorized Flue Damper Bearing Lubrication

StanKatz

I have been lubricating the bearings in my D91 motorized Honeywell flue damper with heat valve lubricant with graphite originally meant for automotive use for 1970s era cars. Someone has warned me that the bearing are not metal and the solvent in the heat valve lube could ruin the bearings. I've been using this lube for over 5 years. The damper has started squeaking this heating season. Can anyone suggest the proper lube?

109A_5

Not finding anything on a D91, the M91 manual does not mention any periodic lubrication. You may have to inspect the unit to see what is actually squeaking, the damage may have already been done.

Wow I forgot all about heat riser valves.

Jamie Hall

As a general sort of thing, if the bushings/sleeve bearings are "plastic" (usually nylon or Delrin or something of the sort) they shouldn't be lubricated at all — nor should they need lubrication. Sometimes the shaft may become corroded or gunky and must be cleaned, but that takes disassembly — which may or may not be feasible.

Nor, for that matter, should oilite bearings (sintered bronze) need relubrication, at least for a very long time — and if they do seem to, it's usually a sign that they are tired.

On the other hand, metal on metal bearings — usually a slightly softer material for the bushing or shell and a harder shaft — must be kept lubricated or greased, depending on the design.

Larry Weingarten

I'm wondering if a dry graphite powder could be used here? It used to be available for locks. 🤔 Probably not a great idea to breathe it ☠️

Yours, Larry

EdTheHeaterMan

ask any Cub Scout who has participated in the pinewood derby. He will know where the graphite is in the garage.

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1843361#Comment_1843361

The 3 in 1 people and a firm trading as "Lock Ease" both make graphite lubricant products in a spray. The carrier liquid evaporates completely, leaving only the graphite. Great stuff.