Hotpoint Stove is Overheating

[kelly0721]

My early to mid-sixties Hotpoint stove, catalog number 108RB 3320, serial number WW 0030349, is overheating. I realized there was a problem after I roasted a chicken, which finished cooking in three hours, 2+ hours faster than called for cook time. Fortunately, I had inserted a meat thermometer, which prevented it from burning.

I then tested the stove temperature with an oven thermometer. It was difficult to get a stable temperature reading at any temp setting, but I would guess it is approximately 50 degrees hotter than the temperature set on the oven knob.

Does anyone know what part I need to purchase for this issue? And, is this an easy fix that I could do myself, or do I need to call a repair person? I have included a photo of the serial number plate on the stove. Any help would be greatly appreciated! Thanks!

 

[ea56]

Try taking the oven control knob off by pulling it straight off the switch stem. Now look on the back of the control knob and see if there is a small screw and a half circle over the screw with a plus (+) sign on one end of the half circle and a minus (-) sign on the other end.

If there is a screw with these markings, loosen the screw and turn the back of the control towards the minus sign a couple of clicks. Now tighten the screw back down, put the control back onto the switch stem and set the oven control to 350 F and place an oven thermometer in the center of the oven, wait until the oven heating light goes out and check to see what the temperature is, preferably with the oven door closed if you can see the thermometer thru the oven window.

If the temperature is at 350 F you’re good to go. If not repeat the process of loosening the screw and rotating the back of the knob to either the plus of minus side depending upon whether the oven was hotter than 350 F or cooler, making the adjustments one click at a time. Repeat this process until you get the oven thermometer to read 350 F after the preheating cycle.

If this doesn’t work you probably need a new oven thermostat control.

Others on this site may have another suggestion, but this simple control knob adjustment has worked for me in the past.

Good luck, and BTW thats a very nice vintage Hotpoint electric stove!

Eddie

 

[kelly0721]

Knob

Hi Eddie, Thanks for replying to my post! I pulled off the knob, but I don't see a screw. See photo. I tried to gently adjust what I have on the reverse of my knob with a screwdriver, but it will not move. I didn't want to force it, so may try to soak the mechanism in vinegar to remove the rust.

 

[ea56]

Kelly,
Try some WD-40 instead if the vinegar to loosen the adjustment plate. Better yet, do a Google search for the owners manual and I’m pretty sure it will have the instructions for making the adjustment. I’ve never personally seen a oven control switch like this one. It appears that maybe you need to use pliers to grip the center piece to make the adjustment, but I wouldn’t want you to break the control knob.

For the time being you could test the current temp setting using the method described above and see how much hotter your oven is when preheated to 350 F. So if after its preheated at 350 F on the control as its currently adjusted and your oven thermometer reads say 400 F then you know that to get 350 F you need to set you control to 300 F because its running 50 degrees to hot. You’ll at least be able to use your oven this way until you can make a proper adjustment. Hope this helps.

Eddie

 

[kelly0721]

Hi Eddie,

I have some WD-40 and will try it instead of the vinegar.

I have not had any luck finding an owner's manual for my stove. I have had the toughest time finding any information on my particular model. I have found a few close matches, but not my model number. The closest I have found to my model number is an RB330-D, but the photo shows push buttons and knobs and looks to be a fancier model. I am still looking, so I will see what I can find. Thanks again for your assistance!

 

[ea56]

Hi Kelly,
If you can access the manual that you just referred to in the above post you will probably find what your looking for because the oven control knob looks to be similar to yours and the stove is of the same vintage. I’ll bet the rent that you’ll find instructions you need on how to adjust your oven control knob there. Good luck!

Eddie

 

[wiskybill]

Oven knob

I think this particular knob is a "friction" adjustment, no set screw.

Hold on to the knob on front and gently rotate the outer ring to adjust.

Just my guess...Bill

 

[rp2813]

It appears that the maximum adjustment from the current setting on the knob is 40 degrees in either direction.  If the temperature is off by 50 degrees, then this seems to me more like a thermostat/sensing unit issue.

 

[kelly0721]

Eddie, I am scouring the internet right now to find a manual. Wish me luck! Thank you for your help!

Bill, You were right! I easily was able to adjust the knob with your directions. Thank you!

RP2813, Because I was not able to get an exact number on how much hotter the oven was than what the knob indicated, I purchased a better oven thermometer that will be delivered today. I am going to double-check my results from the first test. Now that I am aware of the need to adjust the back of the knob, I can perform a more thorough test to see if I need a new thermostat/sensing unit or not. I appreciate your insight. Thank you!

I will keep you all posted.

 

[ea56]

Kelly I’m so glad that you were able to adjust the control know with Whiskybill’s instructions. Duh, I should have been able to figure out that this was a friction held control knob. That’s why it’s so great to have the many members here on AW.org to provide their knowledge and skills to help each other out.

I sure hope that when you finally get a chance to check out your oven temp accurately that it won’t be off more that 50 degrees. Then it should be an easy fix for you to make.

Good Luck!

Eddie

 

[goatfarmer]

Is there a hole in the shaft that the knob was on? Sometimes there is a screw in the center of that shaft, to adjust temperature.

 

[fisherpaykel]

Testing temp after preheated

Hi Kelly for the most accurate oven temperature reading it would probably be best to wait close to half an hour for all parts of oven to reach a stable temperature, such that the the oven control has cycled on and off a few times and be aware that all ovens heat to a little over the set temp. and wait to a little under set temp before turning the heat back on, + and - 10 degrees would be great and a range of 20 degrees + and - would still be acceptable.

 

[Unimatic1140]

Hi Kelly, so your range is very similar to the Hotpoint RB-335, which is a 1964 & 1965 model. I suspect your model may be a year newer or a year older.

I have the service manual to the RB-335 available in the Ephemera Library here:
You may want to download this as it may have other information you might need at some point:

1965 Hotpoint Range Service Manual

In this manual it shows this:

 

[sudsmaster]

Also, the best oven thermometer, in my experience, would be one with a horizontal glass tube filled with mercury. The ones with little wound springs of bimetal can and will go off. The glass/mercury type is far less prone to maladjustment. Unless, of course, they break. There is that.