Honeywell pressure switch
Has anyone noticed a lot of these Honeywell pressure switches failing on Luxaire/York furnaces? Its the one that measures pressure difference between the exaust and intake on direct vent systems.
The switch I'm looking at is a model 9371-DO-HS-0010 and it has failed already in less than a year after replacing the first time. Now, giving it a bump will get it working again for a while until it sticks again (sounds real safe, right?).
Is it...
A positive or negative pressure switch? (monitors inducer or HX)
I've found on reoccurring issues the number of elbows or length or vent was right at max.
Working on steam and hot-water systems isn't rocket science....it's actually much harder.
negative
It says -1.00WC on it so I'm assuming thats a negative pressure switch.
I know the exhaust and intake lines are almost identical, one has an extra 45 to offset it some. Also the lines are 1 elbow short of the recommended maximum except the intake has that extra 45 which moves it even closer to the max I guess.
Would modifying the lines and removing any elbows possible give the switch less of a chance of failing?
This post was edited by an admin on December 9, 2012 11:00 PM.
Yes
I would say not being 1 45* elow from max would surely help. Fieldpiece makes a sweet new pressure switch testing instrument but I don't have one yet because a failed pressure switch is uncommon. It's more likely your altitude or fittings/pipe size being near max. You can increase pipe size if fewer fittings is not possible. Use your analyzer to test negative pressure at the inducer.
Working on steam and hot-water systems isn't rocket science....it's actually much harder.
altitude
Altitude is around 2000 feet.
After looking at it we decided we can eliminate 4 90 deg ells and replace them with 3 45s.
Thanks for your help, I appreciate it.
This post was edited by an admin on December 10, 2012 9:56 AM.
