My 50-year old wall furnace keeps cycling on and off as it gets near the set temperature. Can I fix this by changing to a new thermostat? It's a 2-conductor cable (no blower).

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    Could we get a Manufacturer and model number. – Paul Logan Dec 19 '17 at 23:03
  • It's one of these classics: williamscomfortprod.com/product/monterey-home-furnaces We have the double model (both sides of the wall) with no blower. The thermostat is one of those old coiled spring contraptions. – Network Effects Dec 20 '17 at 0:52
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    I know I get kicked in the teeth about some of my comments about this, but have you ever thought about replacing a fifty year old furnace? I mean really what is the lifespan of a wall heater. – Retired Master Electrician Dec 20 '17 at 13:30
  • Hey RME, don't confuse us with the facts. However, they still needs to deal with the rapid cycling. – Paul Logan Dec 20 '17 at 15:28

First purchase a new electronic thermostat, $20--$30 Install that in place of the existing stat. Tell us if things change.

  • Yeah, I was kind of thinking along those lines. – Network Effects Dec 20 '17 at 3:58
  • This solved it for a remarkably simple and low-tech reason. The Honeywell digital thermostat I purchased works on 1 degree increments (the old one worked on a windey bimetalic strip). The 1 degree increment forces the furnace to stay on for a long enough period of time that it escapes the unstable equilibrium of the windey bimetalic strip and that translates to at least 1 hour intervals even on cold days. Problem solved. – Network Effects Jan 12 '18 at 21:18
  • @NetworkEffects If you'll take the tour, you'll see that the proper way to let the world know that a particular answer solved your problem is to click the check-mark next to the answer. You can click the up vote button next to it, too, as a way of adding an additional "thanks". – FreeMan Apr 20 at 13:20

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