Chosen Solution

This twenty-two year old, 8 Cup SuperFast Percolator FCP280-A, coffee maker is heating the water but no longer perking correctly. The heating process is quitting to soon. It finishes to quickly with extremely weak brew but hot water. A visual examination reveals no burned internal parts. Continuity check shows good. My question is which part to replace, the main element, the fuse link or the thermostat? I found parts for it here: http://www.thepartsbiz.com/Farberware_by…

I believe that it is the thermostat that tells it to turn off when it reaches the right temp. So in the case of your coffee percolator I believe that it doesn’t reach the right temp to brew the coffee. Check it with a cooking thermometer(digital works best)and run the pot through a cycle but don’t add any coffee. Once done, stir the water in the pot just enough to get an accurate temp reading. The temperature of the water should be at least 185 degrees. Hope this help with the java….;-)

Two things with incomplete perks - Actually, the perking stops before the temperature reaches at least 185 degrees F. This is normally caused by the thermostat:

  1. Thermostat is defective (must be replace) or

  2. Thermostat (flat disk portion) is not contacting the metal pot properly: a) Should be fairly high pressure “pressing down” on the disk to make good contact with the coffeepot metal floor (senses the temperature of the metal floor). Note: different coffeepot designs use different methods of applying good/high pressure on the disk portion of the thermostat (Examples: piece of silicon rubber, spring metal, etc.) Note that you must not electrically short out the disk - must be electrically isolated and current can only flow through the thermostat through the proper electrical contacts (blades, brass leads/screws, etc.). b) Use a little bit of thermal paste (same stuff as for computer chips) on the bottom of the disk where it would contact the coffeepot metal floor. c) Lightly sand the bottom of the disk to remove oxides and also to make sure that the bottom of the disk is flat and thereby makes maximum surface and thermal contact with the coffeepot metal floor. Do these three things (a, b, & c) with the existing/“Defective” thermostat and run a brewing cycle before you replace (throw away) the existing/“Defective” thermostat (Most of the time, the thermostat is probably OK - I have “salvaged” most thermostats this way). Bottom Line: Thermostat disk must make good thermal/physical contact with the floor of the coffeepot. Period. With poor contact (pressure too light, inadequate surface area, oxides on surface, etc.), thermostat will be “tricked” into thinking that the proper brewing temperature has been reached and will stop the current flow through the thermostat (thermostat contacts will open at the proper brewing temperature, which is at least 185 degrees F). After perking stops, the water/coffee should be measured to confirm proper temperature. Once the thermostat contacts open, then the “Warming Circuit” will keep the coffee at a slightly lower temperature (maybe 10 degrees cooler) forever, until the coffeepot is unplugged. Note that a thermostat is “Normally Closed” at room temperature (very low resistance - virtually a dead short) and does not open up until a certain temperature is reached - at least 185 degrees F, but could be as high as 205 degrees F - this is a function built into the thermostat and some Thermostats will have the Temperature Stamped on the disk/thermostat. Zenon

  3. Sanding the “thermo” is not enough - lightly sanding the mating surface (usually steel) is necessary.

  4. Thermostat is NC (Normally Closed), NOT Normally Open (NO). It opens (and thereby cuts off the current to the heating element) when the thermostat temperature (~194 degrees F) is reached (the thermostat should be reading the temperature of the steel floor that it is contacting, which should be the same temperature as the water in the percolator, since both water and steel are both better thermal conductors than air). If the thermostat is not intimately contacting the mating surface, it will not be reading the temperature of the mating surface and, instead, will be reading the temperature of the “air” in the enclosed bottom section of the percolator, which has been heated by the heating element. The air in the bottom (enclosed) area of the percolator gets hot very quickly. The water and the steel floor take much longer to heat up, so if the thermostat is not in intimate contact with the steel floor of the pot, it will read the air temperature instead of the steel temperature and will shut down (Open up) before the water reaches 194 degrees.

  5. Most thermostats have some type of device to press the thermostat against the steel floor for tight, intimate contact. Could be a spring or piece of silicon rubber, etc., but it is critical that the pressure device be aligned to hold the thermostat flush and tight against the steel floor (need intimate thermal conductivity between the thermostat and the metal floor).

  6. The spring and the tube are important for several reasons: a) the spring holds the bottom of the tube in intimate contact (tight) with the “well” in the bottom of the pot, so that the water that is heated in the “well” (superheated water) all goes up the tube (does not escape out the sides of the bottom of the tube to the bottom of the pot) and percolates through the coffee, heating the water from the top down, b) the tube must be free of obstructions or restrictions, so that all of the superheated water in the well can freely go up the tube, continuously, removing some heat from the bottom of the pot and transferring it to the top of the pot. Over time, the temperature of the water at the top of the pot will closely match the temperature at the bottom of the pot. c) the water going up the tube heats the pot of water (percolates) “from the top down”, instead of just heating the water from the bottom up, the hot water going up the tube slows down the heating up of the water near the bottom of the pot, extends the percolating process, and extends the time before the thermostat actually “senses” the floor/thermostat to be at 194 degrees. d) If you removed the tube and just plugged in the pot of cold water, even with a good thermostat in intimate contact with the floor, you would have a situation where the floor of the pot was very hot, but the water was not, and the thermostat would trip (turn off) before the entire pot of water got to 194 degrees, because the metal floor could get to 194 degrees before the whole pot of water got to 194 degrees (steel is a much better thermal conductor than water). I would not be surprised if the pot of water was only at 150 degrees when the thermostat tripped at 194 degrees. The principle is simple and effective. There are a few things that can go wrong, and the thermostat is one of the most important things, but not the only thing that can contribute to poor percolating. Easy Maintenance Items, to be regularly addressed: A) The inside of the well must be very clean, so that the maximum amount of heat can be transferred to the inside of the well, to “superheat” the water in the well, allowing it to go up the tube. B) The Tube must be clear of obstructions, and C) The spring on the tube must be strong enough to apply good pressure on the tube against the well. D) The bottom of the tube should not be damaged and must fit tightly against the well. More Difficult Maintenance Items, but should only need to be addressed occasionally, if done properly: E) The thermostat must be in intimate contact with the metal floor, perfectly flat (flush), with some pressure against the floor, and with surface contaminants (oxides) cleaned off the surface of the floor and off the surface of the thermostat that contacts the floor. Last piece of information: Once the thermostat trips Open (shuts off the main current to the heating element), there is normally some type of “warming” circuit that kicks in, maintaining the coffee/water temperature, usually at a temperature lower than the “trip” temperature of 194 degrees….but this is not always the case. I have tested coffee pots where the “warming” circuit keeps the coffee/water at higher than the thermostat temperature (above 194 degrees), in the 200+ degree range…and the thermostat does not care, because it has already tripped OFF. Remember that the percolator does NOT have a timing circuit to turn off the percolator after a fixed amount of time, as many of the new Drip Coffeemakers do, which is typically two hours. You need to unplug the percolator to turn it off.

We’ve had a 12-cup Hamilton Beach for quite a few years and it quit perking at the desired length of time a while back. I’ve been pouring hot water through the basket to make coffee for a while, what a pain. Taking a cue from Zenon I got my Dremel out and using a small wire brush and various other grinding implements I cleaned/shined the heating element in the bottom of the pot including the large thimble shaped opening in the bottom. I filled with water and plugged it in with the basket and tube in place and it perked for 12 minutes and the water temp was measured at 185 deg. Thanks for pointing out a simplified way of “fixing” the thermostat.

Vicky, do some basic checks first, before you even think about starting to replace items. Do some basic maintenance FIRST:

  1. Clean out the “well” in the bottom of the coffeemaker,
  2. Make sure that the spreader is positioned on the tube and spring so that the spring is pushing the tube down with good pressure.
  3. Make sure that the tube is not clogged or plugged.
  4. Run a cleaning cycle using at least 6 tablespoons of Cascade dishwasher powder (my preferred cleaner) in place of the coffee, depending on how much COLD water you put in the coffeemaker. But the water should NEVER be warmer than around 55 degrees Fahrenheit - if warmer, coffee will NOT PERK PROPERLY.]
  5. Record the time to perk and the temperature of the water after the coffeemaker stops “perking” (listen for the “click” of the thermostat when the perking stops).
  6. Now come back and tell us what you found out, such as: Time to Perk, Water Temperature, Spring was weak, Tube was plugged, Well was filthy, etc. Zenon

Have any of you had any luck repositioning the thermostat? I’m curious to know whether this might allow the water to reach a higher temperature before the thermostat shuts down the brewing process.

Mine did the same thing, replaced the thermostat and in 15 minutes I had a great pot of coffee.

Some more rules/guidelines for percolating coffee:

  1. The “thimble’’ or well in the bottom of the percolator must be absolutely clean, not blackened with coffee residue (looks like tar) - use steel wool and elbow grease to clean the inside of the well.
  2. The tube must be free of blockage
  3. The spring on the tube applies downward pressure on the tube, keeping it tight in the well. Here are the principles for percolating the water in the well: The heating element encircles the well, heating up the small amount of water in the well to “boiling”, which forces the water up the tube, to the top, where it sprays out, over, and through the coffee grounds (this is the repetitive process of percolating) and also slightly heats up the water in the pot. If the inside of the well is coated with insulating material (tar/residue), the water in the well will not heat up properly and will not be brought up to percolating temperature. The water that sprays out of the tube also gradually heats up the rest of the water in the pot. The water traveling up the tube also heats up the water in the coffeepot, so in one “refinement/improvement” for percolators, you may have a tube that has a ceramic or insulating material over most of the length of the tube, to keep the water traveling up the tube as hot as possible before it sprays over the coffee grounds. However, the heating element is also heating up the floor of the coffeepot, where the thermostat is in intimate contact with the floor. The cold water in the metal pot is also keeping the floor of the pot from reaching or “matching” the temperature of the thermostat, until the repetitive percolating process heats up the water to match the temperature of the floor. The thermostat is supposed to be in intimate contact with the bottom of the floor of the coffeepot, so that when the floor of the coffeepot reaches the thermostat fixed temperature (should be around 194 degrees F), the thermostat “opens” and stops the percolating process (you can hear the “click” when the thermostat opens). If the thermostat is not in good contact with the floor of the pot, it may get hot enough (just from the surrounding air only) to be tricked into thinking that the floor temperature of 194 has been reached and it will shut down the percolating process. If the thermostat is not defective and is in good contact with the metal floor of the pot, it will accurately read or measure only the floor temperature and will not shut down until the floor temperature matches the thermostat fixed temperature setting of 194F. With a sufficiently effective percolating process, the metal floor temperature should also match the coffee/water temperature. The bottom (interior) of the coffee pot, where the electricals, heating element, thermostat, etc., are housed (trapped), gets very hot - that is why the bottom (black) area of the coffeepot housing is made of a black thermoset material, which will not melt or soften with high temperatures, but can get brittle and crack with prolonged heat and ageing. Note the extensive use of protective silicone material sleeving, high-temperature wire, high temperature terminals, etc., inside the housing - there is a solid reason for that - the heating element is housed in there, and the air inside the housing gets very hot, in the area of 200 degrees F or more, which is enough to trick a thermostat into thinking that the percolating process is completed. Air is a very poor thermal conductor, but if that is all that a thermostat “sees”, then that is what it will measure. Zenon

The thermostat is often not the issue; its contact with the curved bottom is the issue. Air gets between and the switch measures base air temp rather than water temp, which cuts out earlier. I resolved by sanding surface of both the thermostatic snap switch and the bottom of the pot with 600 grit, to remove oxide/dirt then applying some leftover thermal paste from the last time I changed out a CPU chip. viola hot perfect brew! They should really come from the factory attached with thermal paste: https://www.amazon.com/dp/B01MU2FLVJ Otherwise these Faberware percs are great pots; the only pots that come with standard computer cord connection in the back and the only pots that are all stainless inside; the competing Presto is aluminium down by the heating element

Farberware FCP280 in steady use for about a year, and a number of years owned previously. Brewed great coffee until several weeks ago. Water in pot after percolating not so hot you couldn’t touch it briefly just after brewing. Weak taste–no wonderful aroma of coffee in the morning! Followed the suggestions from Zenon: Buff thermostat and contact area, and used light scouring (non-metal) of percolator well. Also put dishwashing liquid in boiling water in pot to clean interior (approx 1 ounce). Perked just after thermostat and well cleaned, and immediate change in water temp in pot after perk complete. (I used Ifixit to replace an iPhone 4 battery, and found this site to be a great resource!) Thank you!

I have a few 100 cup Westbend and Farberware percolators, and I find the same thing. heats water, and makes the “perking” sound, but just doesnt have enough “umph” to push water through the tube.

I have the problem of a “short perk” , gets hot and perks (and maintains a standing hot temperature after the perk completes) , but doesn’t perk long enough (only for a minute or two) and coffee is too weak . I tried sanding thermo , didn’t help . Actually , I dont understand why a “better contact” would help , if the thermo is “normally open " and closes on reaching it’s high temp , it seems that if it is closing too soon it must be making good contact? , the contact transfers the heat so a “short perk” suggests that either full temp has been reached or that the thermo is defective . If contact was poor wouldn’t the thermo just keep perking forever as full temp would never be reached to close it’s circuit and shut it off? I replaced the thermo with a new 194 F Uxcell , tested the water temp and it was still only in the 150’s F just after perking and shutting off , I hear it “click” when the brewing stops , so is the new thermo defective or is there some other problem? How is the spring a factor? , is that the spring on the coffee pot rod or a thermo holding spring? , because the spring on the coffeeepot rod is set at a fixed position so cant be adjusted .

Pot re perks after 15 minutes from first perk ?

My Faberware percolator coffee pot model 142B heats water to 185 deg F, perking 10 mins only. Should I clean the thermostat? Before I cleaned the well, only heated water to 150 deg., perking 7 mins only. Is 194 deg necessary, and must it perk min of 12 minutes for best results.

Anyone know how the warming circuit works? As best as I can tell there is a 290 ohm resistor in series with the main element. That will feed a reduced voltage, and thereby reducing the output wattage of the main element for warming indefinitely, with no reference to the coffee temp. I also saw a “rope warming element” for sale for these pots, which has me confused. If anyone has cracked the code, I would love to learn. Thanks.

Even if I follow the advice set forth in this thread and do NOT get a noticeable improvement, I still have enjoyed learning the pieces of technical knowledge given by you guys. But seriously, I DO want piping hot strong coffee. Time to get to work.