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Are You Living with a Discolored and Yellowed NuTone Master Station?

Has Your NuTone Radio Intercom Master Station Discolored and Turned Yellow?

A big problem with many models of NuTone Radio Intercom Master Stations are that over time the Master Stations discolor and turn from their original White or Bright White to a sickly yellow.

This happens due to a complex chemical reaction in the plastic after it has been exposed to Ultra-Violet light from the sun.

Many types of plastics used in consumer products are made from a formula that includes the chemical compound Bromide. Bromide is added to the plastic to help make it more fire-retardant.

When the plastic is exposed to UV light for a long period of time, the bromide (which is a naturally brownish color) reacts and slowly turns the plastic into a yellowish color. The yellowing effects only the surface of the plastic, keeps the original color just below the surface

This yellowing of plastics is very common, especially with consumer products made in the early 1980's through the mid 2000's.

Many of the NuTone Master Stations we receive in the shop for repair are severely discolored. Even after the electronics are repaired and the faceplates have been cleaned, the yellowed faceplate makes the Master Station look unsightly.

As it turns out, there is a process that can reverse the chemical reaction in the plastic and restore the face plate almost to it's original color.

By using a mixture of concentrated Hydrogen-Peroxide, Oxy-Clean, Water, Sun Light and Time, the yellowing process can be reversed.

I have started some trials on the face plate from a NuTone IMA3303WH, which originally was NuTone's “Bright White” finish. My test face plate had discolored to a sickly yellow that no one would want in their kitchen.

As a control for the test, I removed one of the lower doors from the IMA3303's face plate and put it aside. The face plate (with all of the electronics removed), the second door and the push button assembly were place is a transparent plastic tub and the de-yellowing solution was added. A tight fitting lid was placed on the tub and everything was placed outside in direct sunlight. The test began on Saturday, May 3rd at 6 PM.

Red Arrow is untreated door - Blue Arrow is treated door

The pictures which shows the outcome of the test were taken on Sunday, May 4th around 4 PM, which is slightly less than 24 hours of soak time in the solution.

Red Arrow untreated door - Blue Arrow treated door

You can clearly see a dramatic difference in the color between the treated door and the original door.

The pictures were taken under my normal work bench lights and there has been no Photo-Shopping of the images.

After I took the pictures, the door was placed back in the solution with the face place and button assembly. The test will continue until Saturday, May 10th giving the items a total of 168 hours of soak time.

For this to be a viable process, the exact formula of the solution will have to be standardized and a proper method of testing the solution to determine if it's been depleted must be made.

It will also be necessary to test the process on every model of NuTone Master Station that was available in White or Bright White, to make sure that the process will work on all of the different plastics used.

These Models include: IM3003WH, IM4006WH, IMA4006WH, IM5006, IM3303WH, IMA3303WH, IM3204, IMA3204, IM4406, IMA4406.

It may also be possible to use this process on discolored and yellowed remote speakers, but I will leave that until I have the Master Station testing completed.

I think that this process will allow more homeowners to keep their original NuTone Radio Intercom Systems and not have to live with an unsightly Master Station


I will post more pictures after the ongoing test is completed. The next Master Station that will be tested is a IM5006.





Reader Comments (4)

I have the Nutone Intercom master station IMA 4406. The remote station that works with the master station is the model ISA 445 WH. This is a 6 wire remote station. Recently several remote station speakers have gone bad and I have been unable to locate a place to purchase the speakers that would fit into the frame and replace the bad speakers. I know its the speaker because when I swap out the bad speakers with a speaker from a working remote station, it works fine. They are a 5 inch 25 ohm speaker. Any suggestions regarding where to buy just the speakers?

July 28, 2014 | Unregistered CommenterBill

Hi Bill,

We stock genuine NuTone replacement speaker cones. Please call our office to arrange to have some sent to you


July 28, 2014 | Registered CommenterCindy & Christopher

I have a nutone system (the most elaborate one shown, but I forget the number). It works very well, after only one repair in 30 years, to the master station. The cover though is yellowed and needs to be cleaned.
Can I just take the cover off myself ( and if so, how?) or is this a job for the technician who fixed the innards?
Once it's off, is there anything that needs to be protected while it's being cleaned?
Is there any solution I could wipe on the surface without taking the cover off that would work over time?

March 7, 2015 | Unregistered CommenterJudy

Hi Judy,

The process of whitening a Master Station face plate requires that all of the electronics be completely removed from the back of the face plate, otherwise they will be ruined. This is not something that most people can do themselves.

As for the preparation of the face plate, it varies from model to model. We are the only company that I know of that is doing whitening of face plates. Usually we offer the whitening as part of the rebuilding process when a customer sends in the Master Station for repair.

There isn't any wipe on solution that will whiten the face plate that I am aware of.

If you are interested in have your Master Station whitened, please fill out an Intercom Repair Request Form (located under the NAVIGATION HEADING) on every page of this site. After I receive the Repair Form, I will contact you about your unit.


March 9, 2015 | Registered CommenterCindy & Christopher

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