Re: Robertshaw mechanical thermostat

On 2025-06-25 8:45 a.m., Fred wrote:

micky says...
   > When I thought this was a mercury switch, before I  read
  > it a second time, I thought it likely a wire to the
  > swtich had broken where it flexed.  Even good wire could
  > break after 45 years.  But a reed switch changes the
  > odds towards a failed switch.
 Thanks very much for the reply.  Yes, my conclusion was that
while a mercury bulb could last forever, a reed switch is
going to wear out eventually.  From contact pitting I would
think, or perhaps an arm would break.
   > What happens if you use measure the voltage across the
  > reed swithc when the temp and setting calls for AC. It
  > should be zero or teeny-weeny if the switch is good.
 I haven't done that yet, but will give it a try if I can get
the front cover off - it's not clear how that's supposed to
happen.  Probably just a friction fit.
   > But I don't remember or never knew if AC starts promptly
  > when the thermostat tells it to.
 Yes, the blower motor starts immediately when the thermostat
switches.  I really don't think there's a problem with the
AC itself.
   >> Does anyone have a recommendation on a simple
  >> non-programmable Heat/Cool thermostat?  Or a brand to
  >> avoid?
   > FWIW https://www.ebay.com/itm/277091077135  $55 -S&H
  > after all t hese years
 Yeah, but if I'm going to replace it, I think I'll just get
a "modern" one at Home Depot for less money.  I don't need
it to be programmable, but I would like to be able to adjust
the hysteresis.
 

I have a variety of Reed Switches for sale for classic arcade games, but I expect it would cost less to just replace the thermostat than buying and shipping a NOS reed switch...
https://flippers.com/catalog_oc/index.php?route=product/search&search=reed%20switch
John :-#)#
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