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Fixed High Limit ECO

Alan (California Radiant) Forbes
Alan (California Radiant) Forbes Member Posts: 3,979
edited June 2021 in THE MAIN WALL
One of my customers has an older A.O. Smith Burkay water heater heating a DHW storage tank. It's been acting up; flame and pilot light are extinguished at random times and the fixed high limit ECO is the suspect. White-Rogers no longer sells this part and there is no replacement. A.O. Smith says to replace the water heater.

I'm tempted to replace the ECO with a simple Honeywell aquastat, but getting so close to retirement, I'm worried about liability, specifically the act of replacing an OEM part with something that I come up with. What would you do?

The water heater is 27 years old, but these Burkay's last forever.


8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455
    They still make Burkay's. What are they using for a control now?

    I would replace it with something. Is this the operating control or high limit? Could you put a strap on control on a pipe to operate and a manual reset high limit in the tank? Then you could sleep good at night
  • Yes, Burkay's are still around, but not allowed in the Bay Area - only high efficiency equipment.

    This is the high limit. Sleep doesn't come easy.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455
    @Alan (California Radiant) Forbes

    If it has an operating control then I would replace the high limit with a manual reset high limit aquastat. Honeywell # L4006E I think.

    Maybe you can find what the old WR would cross to. I wouldn't hesitate to do it
  • mattmia2
    mattmia2 Member Posts: 9,576
    It seems possible but very unlikely that a control that never operates is the cause of the problem.
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 3,979
    edited June 2021
    It seems possible but very unlikely that a control that never operates is the cause of the problem.
    You're right, but I haven't been to the job yet. A plumber friend sussed it out and concluded it was the high limit. I'm going by next week to see for myself. If it's new enough to have an ignition control module, I'd suspect that before the ECO.

    The problem is intermittent and the heater has been working fine these last few days.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • I visited the job this morning. Large house with 12 bathrooms; tony neighborhood; just two people. Who knows why people need that much room. Guests, maybe.

    The boiler hasn't acted up again, so they are going to leave it alone. Considering their moderate hot water demands, I suggested a normal 75 gallon atmospheric replacement if and when they want to switch.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • tim smith
    tim smith Member Posts: 2,752
    One of the main reasons we see this problem is they need water side post purge. We use AO Smith thermal balancer for pump circuit to post purge for appx 2 min after call for hot water has been met. The flywheel effect of coil and heat exchanger in boiler is enough to raise the temp of water 20+ degrees if no post purge.
    Good Luck
    Tim
    mattmia2Alan (California Radiant) Forbes