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Tripping honeywell Controller

I've used this site befor with great sucsess but have'nt been for awhile hope I'am at the right place with the right person. I have 2 Kewanee # M-95-K6,950MBH, 28.4 HP, Firing Range 725-1188MBH,WP 15 PSIG, HS 118 Sq Ft, Valve Cap 944 lb per hr.
A Honeywell R4795 with a Q270A base runs them, but lately they have been tripping off after they seem to try and fire after they are comming off our E.M.S. set back. I and a service tech baffold to what is the cause? Maybe heat? He says his readings are good with millivots and current readings. I'drivin a G-rod and wired the controller to that for stray volts. Any insite is greatly appreciated

Thank You
Jim Shea
District Elec.


  • carol_3
    carol_3 Member Posts: 397

    I'm going to have to ask for some help on this one. Flame Safeguard isn't my strong suit. I'll be back to you.
    EBEBRATT-Ed Member Posts: 15,613

    I have a lot of experence with commercial power gas burners although I am not famalier with the Kewanee burner.

    Since it fails coming out of night setback I would say that you have one of two problems. 1. The pilot is not lighting. or 2. The flame signal is erratic or boderline.

    One way to eliminate problems that you can't find easily is to eleminate something until the problem shows up. Some suggestions.

    1. If it fails on a cold start coming out of night setback don't let it setback for a week and see if the problem goes away.

    2. Check all wiring connections to the ignition transformer, gas solenoid valve and flame safeguard

    3. Check the voltage to the ignition system. An ignition transformer rater 120 primary and 6000 secondary will only give you 6000 if you put 120 into it. If you give it low voltage input the output will drop proportially.

    4. Check the flame detector wiring against the manufacturers requirements and make sure it is clean and tight. If the flame signal is low work to improve it. You want the HIGHEST STEADY reading you can get. Low voltage will also hurt the flame signal.

    5. Sometimes changing the ignition transformer to a higher output (swap a 120/8000 for the 120/6000) will help.

    6. make sure the ignitor is set correctly.

    Hope this helps! Burner lockouts are very frustrating and take a lot of patience.

  • carol_3
    carol_3 Member Posts: 397

    The Honeywell expert says that the only thing that locks-up a R4795 is not receiving an adequate 1.5- 2.0 micro-amp signal in 15 secs.

    Lots of things can cause this. You can look at the the tech literature by going to customer.honeywell.com (no www), and entering R4795 in the box at the very bottom right corner. Then click on the arrow beside the box. You'll get a list of the literature about this control.
  • Ron Johnson
    Ron Johnson Member Posts: 4

    Can I get a Thermostat that does not have a anticipator. I get about 2 degree over run. I end up heating heat. If I s
    et the thermostat at 71 I'll get 75-76 in my apartment.
  • carol_3
    carol_3 Member Posts: 397

    The anticipator is what tells the thermostat how often to cycle, so you don't really want a thrmostat without one. You probably need to correctly set your anticipator. Chances are it somehow got pushed out of adjustment to the far end of the scale, and that's why your heat over-runs. So here are the guidlines--If you have forced air or fin tube hydronic, you're looking for about 6 cycles per hour. To get that, you set your anticipator to match the amp draw of the heating load (the gas valve or oil primary if it's forced air; the zone valve or zone pump if it's hot water heat). If you're at a loss as to what the amp draw is, and don't have a meter, try setting the anticipator for about .3. If you have cast iron radiators, you should have about 3 cycles per hour, which would be 1.2 x the amp draw of the load.
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