Anyone know what this control is?

KCA_2

It's working on an 80 or so year old hot water boiler..........

24V ..... likely a relay but?????? Lol

It actually has tubes, like the old TV's. Did..... comes with a cover for the tubes, likely so they don't get hit......

I've looked on line and find that it's called an outdoor reset control, but no pictures and the ones that do post a picture, are wrong...... not the same control..... non-the-less, it could be a 1954 outdoor reset..... one of the first... lol

:-)) KCA

Docfletcher

From what I've found out it is a low voltage 3 wire thermostat controller from around 1960. Should have a round thermostat to go with it.

ChrisJ

24 volt?
I find that a bit hard to believe with tubes. Typically tubes need a DC plate voltage of anywhere from 100V and up, I've worked on amplifiers running on 650VDC.

I can see the heaters are good on the tube on the right, but can't tell about the one on the left. Is it working?

Perhaps @Steamhead has seen something like this?

ChrisJ

Actually,
Found this pretty quick.

https://heatinghelp.com/assets/documents/138.pdf

Docfletcher

Here It Is In Life Magizine...

https://books.google.com/books?id=VVIEAAAAMBAJ&pg=PA73&lpg=PA73&dq=Honeywell+Electronic+Moduflow+control+system&source=bl&ots=1gUCOHNDDE&sig=EzPVrEKohalLxapCQ-rjza8j8nk&hl=en&sa=X&ved=0ahUKEwiCsv-70qjLAhVjmYMKHWAWA4cQ6AEIQjAH#v=onepage&q=Honeywell Electronic Moduflow control system&f=false

KCA_2

That's a pretty good likeness..... yeah.... that could be it!

Docfletcher

Yeah the 24v thermostat controller info I posted came from justanswer.com . Seems a fellow had one and was asking a tech about it.

Docfletcher

Here is an old partial listing from Ebay. Also a link to thermostat.

You are bidding on a vintage, Honeywell electronic "Moduflow" temperature control system with the "Golden Circle" day/night wall thermostat. There are supposed to be 3 parts to this system: the wall clock, the wall thermostat and the exterior thermometer. (the outside thermometer that is on the outside of the house has been painted over so it is NOT included in this bid.) Your bid will come with the 2 pieces I have.)

http://screencast.com/t/f6vMyyuE4h

Docfletcher

Here is the inside of the Thermostat And larger photo with cover. Notice there is only 2 wires.

http://screencast.com/t/pKPb346WZ6TF

http://screencast.com/t/2FNg186t7

bob_46

vacuum tubes were common in MH and Fire-eye burner controls thru the 60's.

lchmb

That stuff is awsome...Everyone laugh's over the old stuff I collect in my garage but it show's how things developed over time...