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  1. #1
    Join Date
    Mar 2008
    Location
    Jackson, NJ
    Posts
    176

    Question Cycle Time Adjustment ?

    Hey Gang,

    Can the cycle time be adjusted at the blower/heatpump/furnace and not just at the stat?

    My HVAC guy came by and spent awhile downstairs. He said he increased the cycle time but didn't go into detail as to how (and I couldn't ask as my boss was sitting across from me when he called in to say he left the house). I asked if he changed the CPM at the stat and he said 'No, I took care of the timing at the unit'.

    Any idea what he could've done? He was already by once to slow the fan speed (didnt work). Maybe he could've lowered it some more? I don't know. It hasn't been that hot here so I can't see if anything is better /worse yet.

  2. #2
    Join Date
    Mar 2007
    Location
    A Lan Far, Far Away in Podunk, Georgia
    Posts
    234
    This is an outrageous answer but.... when I want my heat pump to run longer, I simply lower or raise the thermostat setting a few degrees past where I actually want it. It just sets there and runs until that'ol thermostat is satisfied.
    That seems to magically make it do what I want.

    Sorry if I didn't understand your question.

  3. #3
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,748
    only thing that can be adjusted at the furnace may be the fan off delay or the blower speed. cycle rate is the job of the thermostat.

  4. #4
    Join Date
    Mar 2008
    Location
    Jackson, NJ
    Posts
    176
    Well, whatever he did now its really screwed up. The stat calls for cool and the compressor doesn't kick on for over 10 minutes.

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,168
    Maybe he installed a delay relay, to hold off the compressor only.
    So that you think the A/C is running longer.
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  6. #6
    Join Date
    Mar 2008
    Location
    Jackson, NJ
    Posts
    176
    Quote Originally Posted by beenthere View Post
    Maybe he installed a delay relay, to hold off the compressor only.
    So that you think the A/C is running longer.
    That's what I was thinking, though I didn't know the technical particulars. But now the system calls for Cold, waits anywhere from 10-40 minutes, then fires off the compressor. Its all botched up now. My HVAC guy thinks something happened to the board outside on the Heat Pump, but wants to come back to diagnose.

    What a pain this is becoming.

    He DID tell me that it is normal for the system to call for cold, and have the fan run for 5 minutes or so before the compressor fires up. He said there is a delay from when the system 'energizes' to when the compressor will actually turn on. I've never experienced a system like that before, but he is fairly adamament that this is normal behavior for this Ruud.

  7. #7
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,168
    The stat and defrost board both have 5 minute anti short cycle timers bult into them.
    But they only prevent you from restarting your system quicker then 5 minutes.
    If your system has been off for 10 minutes and you adjust your stat to call, they should come on right away.

    After all, a 40 minute delay,would allow the temp to rise fairly high when the OD temp was near design.
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  8. #8
    Join Date
    Mar 2008
    Location
    Jackson, NJ
    Posts
    176
    Quote Originally Posted by beenthere View Post
    The stat and defrost board both have 5 minute anti short cycle timers bult into them.
    But they only prevent you from restarting your system quicker then 5 minutes.
    If your system has been off for 10 minutes and you adjust your stat to call, they should come on right away.

    After all, a 40 minute delay,would allow the temp to rise fairly high when the OD temp was near design.
    That's what I thought too. And that's the way the system was behaving before whatever went south. Hopefully its as simple as replacing the outside board.

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