Nordyne M1MB 070 pressure sensing problem

[mattmann]

Nordyne Model# M1MB 070A BW Series
M1M 990605682
I previously had a problem where my pressure switch wasn't sensing a draft. I removed the black part where the PS hoses connect to and found that the internal connector (lower) on the black part(draft inducer?) was broken. I rigged it with a new nipple and tube which allowed the internal tube to be over the draft. I had taken the part to the local HVAC supplier who told me that they don't carry Nordyne parts and that I would be lucky if the unit still worked after a few years.
I am again having some trouble with this part. The external putty I used to keep the nipple attached has hardened and probably allows air to enter/escape.The two hoses are also a little sloppy. My heat was not starting-draftfan running without sensing the draft-two red flashes. I turned the hoses around to make a better connection and was able to get heat again.
What are the part numbers for a new black box(draft inducer?) which the pressure switch hoses connect to? I also need new hose and I would think that a new pressure switch wouldnt hurt either.
Any thoughts or part numbers?
Thank You

[Robert]

Hi,

Is it just the flow probe that is broken ? If so, you can buy it only and not need the whole combustion motor assembly.



Thanks,
Robert

[mattmann]

Yes, I have a flow probe which is broken. Which part number is that? I also will need tubing and do you need to seal the black flow box when you reinstall it? Would you also recommend changing out the flow switch at the same time?

Thanks

Matt

[mattmann]

I purchased part numbers:B13-614 Silicone Tubing 12" and 669292R Flow Probe. Does the cumbustion motor assembly need to have gaskets or silicone or anything on the adjoining surfaces when it is reinstalled?

Do you recommend any other parts such as a pressure sensing switch, or do I leave well enough alone if the unit works after the above parts are installed?

Matt

[Robert]

Hi Matt,

Silicone around bottom, under the orifice seal ring at top, and where air pipe comes over top of orifice seal ring.

Pressure Switch # 632453 can be seen and ordered from right side here:

http://www.mobilehomerepair.com/NordyneGas.html


Read the info listed with the switch. because it is somewhat different, though correct, depending on how much tubing you ordered, may want to order some more to ensure you have enough.

Also, due to differences, I would use current pressure switch IF it proves ok as long as it lasts and keep new one for when it fails.

They do fail and usually at worst times, so I consider them a cheap insurance piece.


Thanks,
Robert


Thanks,
Robert