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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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DynaChem has a 1967 Kewanee, 250 HP, gas-fired, fire-tube

Customer Question

DynaChem has a 1967 Kewanee, 250 HP, gas-fired, fire-tube boiler with an E-type burner.We need an electrical schematic for the gas fired system. Since the Kewanee is older than 1970,Are any manuals, drawings or schematics available for this unit. The boiler name plate is as follows:The serial number : NB-23335.The Order Number: 416840AManufacturing year: 1967
JA: Thanks. Can you give me any more details about your issue?
Customer: Jim Hartman, EngineerThe boiler will not go to automatic fire from low fire. When manually put into automatic fire, the boiler operates OK. There are some changes that need to be made . The boiler tuner recommended a new 135 ohm pot and a L91A controller. The wiring is in poor condition. That is why we need the wiring schematic.
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Submitted: 1 year ago.
Category: HVAC
Expert:  Phil replied 1 year ago.

Hello Jim, I do not have a wiring diagram for that boiler, it is almost 50 years old. However very few experienced large scale boiler contractors will have any trouble at all sorting out how it operates and and what is needed in the line of wiring etc.

98% of those used off the shelf fire eye ignition and aquastat controllers (by Honeywell mostly), so far it sounds like you may have found such an experienced man judging by his recommendations so far. These boilers can be a safety hazard, especially fire tube and steam applications over 15 psig, for that reason and to keep your building owners liability insurance properly in force whomever you hire should be a licensed boiler contractor, with full liability insurance. Such boilers when rated over 15 psig steam pressure need regular pressure vessel inspections. These generate hydrogen in the water which embrittles the tubes but more dangerously the pressurized components.

If you have the full model number of the boiler you might be able to find a diagram for it at this link

That is a bit of a long shot, but it is not likely you will find a wiring diagram elsewhere. However as I said, those were controls were straight forward, not electronic and are generally not difficult to sort out for an experienced tech on the job site.

We can go from there if you feel I can be of any further assistance.

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