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HW R4795A Flame Safeguard Primary Control--2K relay chatter??

JUGHNE Member Posts: 10,905
Have that older control (25 years or so). On first light off for the season, I noticed the 2K relay clicking on and off. This is the main burner relay that was clicking before there was even pilot established. (BTY, this is a good reason to valve off the MGV during check out/start up.) SOP.

When 2K pulls in for main burner it interrupts the ignition circuit, so no steady spark during this event.
Has anyone had this happen? I got the air pressure switch to get a better connection by exercising it, that might have been intermittent in continuity. However without FS proving 2K should not be close to closing.

Eventually it did as designed and fired fine, but I did not leave the boiler room as it was on, but can't stay all winter.

I know this model is obsolete, no longer available. One supplier said that the green DC amplifier is no longer available. Purge time boards may be found somewhere.

The up grade (RM series) is about 1/2 the price of the entire burner.
Presently is an Adams Speed flame HP800, 300,000 to 800,000 input.
Wonder about a Carlin 301 for replacement......how involved it would be?


    EBEBRATT-Ed Member Posts: 14,534
    Haven't worked on one of those in a long time!!

    I believe 2k is the flame proven relay so it shouldn't pull in unless you have a flame. If no flame I would suspect a defective control, or amplifier. Since it is a green amplifier is rectification I am guessing it's a flame rod. Can you check the flame signal?? I don't think a defective or shorted flame rod can cause an intermittent problem.

    Not sure what you could use for a reasonable price replacement. You would probably have to scrap the original flame rod and put one in compatable with the new control.

    I suspect it's new burner time.

    I never did a Carlin 301 but have installed several 201 gas burners. No problem they ran great.

    How much input do you actually need?? If you can get away with 499,000 which the 201 will do it's a lt cheaper as over 500,000 the gas train changes completely from a residential type to a commercial type.. more $$$$$$$$
    JUGHNE Member Posts: 10,905
    Ed, thanks for the reply. The 2k relay pulls in the main burner. It should not even get close to engaging without a pilot flame.
    I explained to the owner what happened, we agreed to go with new primary control. The HW RM 7800 series was located at a reasonable price, so that is the plan to upgrade.

    I guess one can fix old stuff for only so long. I don't like to toss this old control, but considering the liability that is the path to go.

    To satisfy the "fix/repair" craving I an currently replacing the seal in a condensate pump (only 5 years old) and will pass up the opportunity to replace the complete unit. Told owners I could probably fix the old for 1/10 the cost of a new one. Maybe.....but certainly less liability....and in the end could look like a good guy. o:)
    EBEBRATT-Ed Member Posts: 14,534
    always difficult to choose between fix and replace....it's a judgement call...sometimes you win sometimes you don't
    JUGHNE Member Posts: 10,905
    I'll know about the cond pump repair tomorrow.
    But the flame guard primary controls I won't let go with "it might be OK" .
    All of these boilers are in schools, churches and hospital.
    EBEBRATT-Ed Member Posts: 14,534
    yeah, too much liability can't take a chance. it's old, done it's job.....sounds like I am talking about myself!!!