Ask Experts Questions for FREE Help !
Ask
    askme233's Avatar
    askme233 Posts: 14, Reputation: 2
    New Member
    		  
    #1

    Jan 5, 2008, 02:02 PM
    Honeywell st9120c Fan Timer
    After numerous tests, it would appear that my Fan Timer module (Honeywell st9120c 2010) is bad. In particular, I can see the lead to relay K1 is burned and I get no power on either output side of it (one is supposed to be for constant fan and the other for auto - so they should be energized alternately).

    So, I have a new timer module ordered, but it is cold in these climes, so...

    I have alternately hooked the main blower through the Humidifier jack which is is energized as soon as the inducer motor fired up. As far as I can tell from both the wiring schematic (Product) and actual tests, this seems identical to having it wired for Constant Fan.

    While not planned to for longer than a couple of days, is this stupid for an reason?

    I was worried that having the circulation fan blowing would prevent ignition, but this does not seem to be a problem.

    Thanks for any insights.
    tsa7man's Avatar
    tsa7man Posts: 154, Reputation: 9
    Junior Member
    		  
    #2

    Jan 5, 2008, 08:31 PM
    You can put your motor lead on the constant on pin and it will not bother the ignition sequence of the furnace, as you stated, the fan will just run all the time...
    askme233's Avatar
    askme233 Posts: 14, Reputation: 2
    New Member
    		  
    #3

    Jan 6, 2008, 10:59 AM
    Thanks. The constant pin is the "open" side of the burned relay and doesn't get power either. As far as I can tell the Himidifier pin is also always onas well.
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Replace old Honeywell timer thermostat [ 19 Answers ]

I have 2 old Honeywell timer thermostats - on 2 floors - wired to my boiler (we have radiant water heating). Both function poorly and I would like to replace with standard round manual thermostats. Problem - I took one of the timer thermostats off the wall - it has 3 wires coming in - 2 black and...

Timer Client/Caf [ 4 Answers ]

Greetings fine folk, 1) First time posting so if I mess up or this is the wrong forum please have mercy :) 2) I work for a medium public library and we are looking for a timer client/café timer for the 12 PCs we have available for library patron use. These 12 PCs are connected to the Internet...

Where can I buy a Honneywell circuit board ST9120C [ 1 Answers ]

Where can I buy a Honneywell circuit board ST9120C

Replacing Honeywell T8411R with Honeywell RTH7500 - wiring problems [ 1 Answers ]

I need help getting my new, programmable thermostat to work. I currently have a dual-stage Heat Pump and A/C unit that works fine. The current thermostat is the Honeywell T8411R. I don't know the number for the subbase, but it's the one that came with the thermostat. The current (operational)...

Auto Timer for Heater Honeywell RH230B [ 2 Answers ]

Please help. I lost my directions and don't know how to tell the timer the day of the week today is. Everything else is programed for days of the week and weekend but how do I tell it what day we're actually on? Would it be possible to get a new set of directions? Thank you.

View more questions Search