WHITE-RODGERS 113322 MERCURY FREE MECHANICAL THERMOSTAT MERCURY FREE MECHANICAL THERMOSTAT|

product fit good and customer was happy. I had to match an old school thermostat in an older house and this one worked like a charm. Shipping was good and fast, easy to use and brought the heat level up to where it needed to be.

This mechanical thermostat is ideal for replacing an old-style model with a mercury-in-glass switch. (Drop old Hg switch at HazMat roundup!) Base dimensions are 2.75" W x 4.5" H, with 2 mounting screws 3.25" apart on the vertical centerline. This model includes a "heat anticipator" which is simply a resistor that gently warms the sensor while heat is on (about 0.1 Watt) to tune overshoot and cycle times. Different furnaces draw differing current to operate, so you must adjust this resistance (about 0 to 2 ohms) to work with your furnace and produce the correct amount of sensor heat within the thermostat. The anticipator is calibrated in Amps, for the current your furnace relay draws when the heat is on. If your old T-stat has an anticipator, copy this setting. My gas furnace was a thermopile-powered "millivolt" system, so I adjusted the anticipator to 0 ohms (the 1.2A setting). The documentation is not entirely clear that the anticipator pointer onto the calibrated scale is opposite the wiper that actually touches the resistance wire. One other adjustment I made was to calibrate the temperature indicator by turning the screw on the back side of the cover; it read about 5 deg F high when received. Trouble free after that.

Easy to install. But not sure on the back mounting plate... couldn't get it off. Working fine on our minivolt system.

It's only 2 wires Only 2 wires that need to cross. And this plastic trash can't even do that.pathetic. they take an old simple concept and completely screw it up with crap parts and everything plastic. It's only 2 frickin wires. I'm searching for a unit made in the 1950s in a garage sale to replace this crap. The Original one will still work perfect. Why do we destroy quality for plastic crap just to make more money

This t stat works as described. I have a gas furnace from the 1930's with a standing pilot, mili volt system. Looks great, works, is designed to screw into an existing electrical box.

Classic appearance, no batteries to worry about, easy install.

I do like the classic and simple design of these and install quite a few for boiler Heat-Only jobs. The catch is every other one I install requires manual fine calibration. Adjusting the thermometer dial is fairly easy. Just pop off the clear faceplate and rotate the dial. Micro-adjustments to the temp lever though is a bit more involved, doable but tedious. Still, unlike the common round T87's (newer models do have electronics) these truly are purely mechanical. For forced air you'll want a different model. But once calibrated, on a basic 2 wire system I find these ideal. **UPDATE** Do NOT recommend these in hydronic boiler systems with zone valves. Every one I've installed the anticipator wire burns out. The nichrome resistance wire can't support the current draw. Specifically with TACO ZV heads. Rather than replace them all, each one was modified by soldering on a 0.5Ω 5W ceramic resistor. Anticipator will no longer be adjustable. But this is approximately equal to std calibration value used by most systems.

Perfect replacement for old thermostat. Easy install and works great.

remplacement du thermostat pour foyer au gaz. Tout est parfait et la livraison fût rapide.

parfait pour remplacer mon ancien Thermostat au mercure de mon foyer au gaz naturel!

I needed a new basic thermostat for my gas fireplace to replace an older one that the plastic had yellowed over the years. Unfortunately a basic on off thermostat like this costs a lot more than many electronic digital thermostats which I wanted to avoid. Easy to install and mercury free.

Foyer propane

This should have been a straight forward installation, two wires connecting to a .750 V system. Didn’t work right off the bat. My neighbour is an electrical engineer and he checked it out with his meter. There was no continuity between the terminals, but if the bare wires were touched to other random contact points, it would connect on some of them.