How to Replace Your Old NuTone or M&S Intercom System

Home Intercoms


Do you have an old NuTone IM or IMA series intercom system in your home that has stopped functioning properly? Has one of your room stations on your M&S System intercom gone bad or has the master station begun to malfunction? Are you looking to expand and upgrade? Home Controls can help!

First, we need to share some bad news

Old NuTone and M&S intercom systems can almost never be replaced piece by piece. These manufacturers do not manufacturer replacement parts for their older models, and the newer systems are not backwards compatible. That means buying a new station to replace just one old or broken station is not an option.

Unfortunately, you need to buy an entirely new setup and replace all of your equipment, including the master intercom station, room intercom stations, patio intercom stations, door intercoms, wall and speaker controls, and even the rough-in box or housing that your master station is mounted in.

It’s not all bad news though. Here’s the good news

There are several new intercom systems that offer retrofit options, meaning you can still use the wiring you already have in your walls, no matter if your previous intercom was installed using 3, 4, 6, or even 8 wires. Also, although the new systems are smaller than the old, you will not have to cut any more holes in the drywall. The newer systems provide retrofit moldings that fit the new components’ holes where your old system is installed.

How To Determine How Many Wires Are In Your Old NuTone System: Before you can order an intercom replacement, you need to determine how many wires are used in your existing intercom system. Carefully remove a room station from your wall and count how many individual wires are connected to the back of the station. It’s that simple! If you need more detailed instructions, then read our blog entitled How Many Wires Are In Your Old NuTone or M&S Intercom System?

There are a several choices that work well as replacements – or what we call retrofit – for old NuTone intercom systems. First, there is the new and current NuTone intercom system, which offers plenty of options to replace and upgrade older systems. Also, there is M&S Systems, which is a popular alternative to NuTone. Third, the newest intercom brand at Home Controls is Intrasonic Technology – or IST – and it offers a newer intercom system with more features than what has been seen in other retrofit choices, including iPod connections and Bluetooth capabilities.

Retrofit Intercoms by NuTone

The NuTone NM100-series retrofit intercom system replaces any old intercom system that has 3 or 4 wires. This retrofit system can accommodate up to 15 room stations and three door stations. The system has two inputs for audio devices and a built-in AM/FM radio.

Remember, just replacing your current master station with this one will not work; you need to replace the master station plus install all new room stations, door stations, rough in box (located behind master station), and plastic fittings for each of the new parts.

Even if you have 6 wires, you can use the NM100, the 3/4-wire retrofit. You would just use either 3 or 4 of the 6 wires depending on what speakers you use (3-wire or 4-wire). For that matter, you can use the NM200 and use all 6 wires. The NM200 uses either 6 wires or Cat5e.

While the NM100 master station can work with both 3 and 4 wire systems, there is one room, door and patio station built specifically for a 3-wire system and a different room, door and patio station built specifically for a 4-wire system. Keep this in mind when ordering.

If you have an existing 6 or 8 wire system, then you should order the NM200-series intercom system, which has identical features as the NM100. (NOTE: The NM200 is also used for new construction installations.)

Home Controls offers convenient NuTone kits for the NM 100 and NM 200 systems, with the master station, four room stations, a door station, a 3-note doorbell chime, and an outdoor station – or you can create your own kit to match your specific needs. Plastic fittings for all the equipment, a rough-in box, and a gap frame for the master station are sold separately.

Retrofit Intercoms by M&S Systems

Another intercom retrofit option is the M&S DMC3/4. This intercom system is similar to NuTone in that it works as a replacement for current home intercom systems. The DMC3/4 is used when you have a 3 or 4 wire intercom configuration. It can support up to 15 room stations and 3 door stations, and offers 8 AM and 8 FM radio preset.

If you have a 6 or 8 wire configuration, then you will use the upgraded M&S system called the DMC1.

Home Controls offers an M&S package deal that comes with a DMC3/4 or DMC1 master station, four room intercoms, one outdoor speaker, a doorbell chime, and a doorbell intercom station. These kits’s are similarly priced as the NuTone kits, and the rough-in box for the master station, or any plastic fittings for the room stations or door stations are sold separately.

Retrofit Intercoms by IST

Although NuTone and M&S systems perform very well and are great intercom solutions, the system with the most features is the Intrasonic Technology intercom system. The IST intercom system supports 17 room stations and two door stations, and supports wires already in place from previous intercom systems, no matter whether there are 3, 4, 6 or 8 wires. The IST system also supports 10 preset AM and FM radio stations.

In addition, the master station has a USB port to charge smart devices and play music. IST also carries a Bluetooth adapter that lets you play your music through a wireless connection using a Bluetooth compatible device.

Home Controls carries an IST kit that includes a master station, a master station adapter cover plate, four room intercom stations, four room adapter cover plates, a door station, and mounting screws. Another difference between this system and the others is that the IST room stations fit into a standard two-gang box, whereas the NuTone and M&S intercom systems are irregularly sized. All of these extra features come at a reasonable price on the Home Controls website.

Another Replacement Option

Another option for replacing your older NuTone or M&S intercom system is to rip all of the wires out of the wall and start over with a new system that uses Cat5 wires, which are Ethernet wires. Systems that run on Cat5 have the advantage of connecting to the Internet, and therefore offer a few more features and perks. The On-Q/Legrand Selective Call Intercom system, for example, has a video door station that can be viewed from a special intercom station inside the house, or from anywhere using an Internet enabling module.

Of course, the process of removing all of the existing wiring and replacing it with new Cat5 wiring is far more labor intensive then merely retrofitting and older system, so you need to balance the cost with the features before you start tearing into your walls.

About Home Controls (410 Articles)
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82 Comments on How to Replace Your Old NuTone or M&S Intercom System

  1. Karen Campbell // June 11, 2015 at 9:46 am // Reply

    The timer light is illuminated and the system was installed in 2006…Not sure what is going on with this, but I can say I have no intercom, radio or C/D access. The entire system shut down and have not seen that light on before. Not sure if it was a power surge or what happened. HELP….if you can. Thanks

    • Karen, this sounds like a job for our technical support team. Please give us a call at 800-266-8765 and we can troubleshoot why your system is not working. Thanks!

    • Can somebody PLEASE make some that look pretty and up to date? All of the ones I can find look so cheap and worse than my old ones.

  2. Ronald Stephens // August 18, 2015 at 3:22 pm // Reply

    I have a Nutone model ST 1000 which doen not work. This is not an intercom but radio and cassett player used for one room only. I would like to replace this with a radio/disc player. Can you help me with this and what would the unit cost.

    • Ronald, feel free to contact our customer service department at 800-266-8765 or They can answers all your questions!

      • Micheale Dewey // August 22, 2016 at 8:21 am //

        Did you call customer service? What did they recommend if I may ask? I would just like to replace my old Nutone model ST 1000. I don’t really want to cut new holes in the sheetrock. I would just like to get one to fit in the hole that is already there.

  3. Andrew Cooper // August 25, 2015 at 3:28 am // Reply

    This post is very helpful and informative as well. Planning to buy a new intercom needs to determine the functionality and the maintenance also just in case you need to replace parts for it.

  4. Ours works pretty well but it only has radio. I got one of those Headphone to FM Tuner devices to hook into my iPhone. Then I tune it, and the Nutone to an available FM station and that’s how I stream my iPhone to the system.

  5. My home was built in the 60″s I have a Nutone system through out the house my model number is 2067-68, I would like an extimated price on an upgrade. Thanks

  6. I have an old broan kn600 with a cd player attached ,i cant find the manual .We are selling the house and I need to fix or replace it ,Can you suggest a replacement please ..

    Thankyou Gerry

  7. I have a NuTone IMA-4006 series intercom which has stopped working, l live in Darien,Il. Please advise me what to do as I can not hear door bell and being handicap get frustrated.

    • We are sorry to hear that your system is not operating properly. I am not sure if we can provide the hands-on assistance you need. As a retail store, Home Controls can provide you with a new intercom system; however, we do not provide installation or repair services.

      We have found many different types of businesses that will offer this service from low-voltage integraters to locksmiths, audio video technicians to gate and garage door installers. The best way we have found is to search “Residential Intercom Installer” plus your city or zip code into an internet search and you should be able to find someone in your area.

  8. We have an old M&S system throughout house that I’d like to totally update. Who do I get to do it for me. Any electrician?? Are there specialists for this? I want to have someone do it all from A to Z. We live in Jupiter, FL.

    • We have found many different types of businesses that will offer this service from low-voltage integraters to locksmiths, audio video technicians to gate and garage door installers. The best way we have found is to search “Residential Intercom Installer” plus your city or zip code into an internet search and you should be able to find someone in your area.

      Make sure you let them know about Home Controls, and we can offer them a great installer’s price on your new intercom system!

  9. Is it possible to add wireless stations to an existing Nutone system?

  10. I have what I belive to be a 20 year old Broan Stereo Intercom system (house was built in 1996) that appears to have 7 connecting wires. It has 12 room stations, 2 door stations, AM/FM radio, CD and Cassette. Do I have the same options listed above to replace the components without having to upgrade the wiring? I’m not really concerned about the tape deck. Thanks

    • Chris, for this one, we would recommend the IST RETRO System. It’s a three-wire system (which means you will only use the first three wires from your existing system) that gives you all the same features and benefits as the other systems.

  11. John Cardamone // April 10, 2016 at 11:03 am // Reply

    I have a Broan K1301 intercom system (installed 1990/1991, what do I exactly need to replace /retrofit? TY

  12. Sylvia Garcia // May 26, 2016 at 12:07 pm // Reply

    Hello, I purchased my home in 2009 (I live in Lake Elsinore, California) and my home had the intercom system already on it. Unfortunately its not working at all anymore :/ and I would like to update the entire system but I too need to know who does this kind of work and how to go about it since I know nothing about this matter.. My home was built in 2004 but the system looks pretty old :/ so I would like to get an updated version. Can you please guide me? Thanks for everything.

  13. Danny Neal // July 10, 2016 at 5:46 pm // Reply

    I have a Nutone/Scovill whole house intercom system with am/fm radio that has stopped working. There is static but nothing else. I am considering replacement but wondering what would be best and most economical route. I have a six wire system. I would like to have the Intercom as well as cd player. I have base unit and seven stations and two door stations which are speakers only. Please give me some info on what would be best system for me.

    • Thank you for your comment. I’ve forwarded it to our technical support department so they can offer you a detailed response.

    • Tech support has offered a response:

      The IST (Intrasonic Technology) system would be an option for you. CD players are no longer being manufactured for retrofit intercom and music systems, however, IST has a Bluetooth receiver as an optional piece. As an example, please take a look at our 4-room system kit here:

      To complete your system using this kit, you would simply need to add one more door station and 3 room stations, along with adapter plates (vertical or horizontal).

      Please give us a call at 1-800-266-8765 and we’ll be glad to check that you have all the pieces you’ll need for a complete system.

      • Naresh Datt // July 13, 2016 at 6:38 am //

        I have a NuTone IMA 4006 intercom and chime module has gone bad. I want to buy chime module only. Please give names where I can buy. I have the part no. Thanks

        Sent from my iPad


    • Naresh, unfortunately Nutone no longer manufactures parts for the IMA 4006, and the newer chime modules that Nutone does make are not compatible with older systems. You might luck out if you are able to find a company that still has the old chime module available, but we have only the newer parts. If you’d like assistance with upgrading your entire system, please give us a call for a quote at 1-800-266-8765. Thank you.

  14. Mary Dwyer // August 8, 2016 at 5:51 pm // Reply

    I have a system that is working fine but the radio stations are not tuned in enough – they sound a bit fuzzy. Is there an antenna that I can add to get a clearer station?

  15. John in atlanta // September 15, 2016 at 6:04 am // Reply

    I have 300 series intercom that was installed in October 2000.
    Resent the radio section will not turn on,but will come on by itself,clock works but nothing else. How do I get the system to dismount from wall? Please help

    • Hi John! If you’re trying to replace the old system with a new one, our tech support team can help you figure out how to do that. You can give them a call at 1-800-266-8765 or email We’re unable to provide repair/installation services, but we can help answer questions about replacement.

  16. If I am replacing the whole system base unit and all speakers then what difference does it make how many wires my old system has?

    • If you want to replace the old system without having to run new wires, you have to make sure the new system is configured to work with the number of wires you have. Not all of the old systems used the same number of wires going to each room station. It could be 3, 4, 6 or 8.

      Some retrofit intercom systems, such as the IST RETRO system, support any number of wires (3, 4, 6, or 8), so if you choose to go with IST, it actually doesn’t make a difference how many wires your old system has. Furthermore, the M&S DMC3/4 retrofit system is designed to support 3- or 4-wire configurations. The new construction M&S system, DMC1, differs in that it uses Cat5 wiring, so it only supports new installations with Cat5 wiring or existing 6- or 8-wire configurations.

  17. So if I have a 6 wire Nutone system I couldn’t use just 3 or 4 of the wires that are run through the house with a retro fit Nutone? If everything is being replaced except the wiring I would think you could use only the number of wires that are needed for the retro system.

    • Richard, I’ve forwarded your question to our tech support department and will follow up with you soon.

      • Richard Blood // October 11, 2016 at 2:54 pm //

        Thank you Kayla. I will wait to hear from you.


      • Tech support replied with this clarification:

        Even if you have 6 wires, you can use the NM100, the 3/4-wire retrofit. You would just use either 3 or 4 of the 6 wires depending on what speakers you use (3-wire or 4-wire). For that matter, you can use the NM200 and use all 6 wires. The NM200 uses either 6 wires or Cat5e.

        Based on this information, it seems we need to update our blog to be more accurate. I’m going to update my original comment as well.

      • Here is some further clarification (again from Bob Grier in tech support):

        The DMC3/4 works the same way. I usually don’t recommend using a DMC1 (or NM200) as a replacement even if you have 6 wires because if one of the 6 wires has a problem you’re stuck. It’s better to use an NM100 or DMC34 because you have unused wires in case you end up with a bad wire.

        The difference between the systems is:
        With the DMC34 you don’t have the Privacy feature
        With the DMC34 in a 3 wire setup you also don’t have the Monitor feature

  18. Vernon fisher // October 26, 2016 at 4:39 am // Reply

    I have a ms intercom system which was installed when I built my home in 2009. Recently there is a constant buzzing (similar to activated smoke detector). I do not know what caused this but the only way to stop the noise is to cut the power to the area at the electricity power box. Is there any other way to solve this problem

    • Response from Bob in tech support:

      The first thing I would suggest is to see if you can power off the main intercom and room stations individually. If that doesn’t work you will need to disconnect power from the master station which will require pulling the unit from the wall and disconnecting the AC power.

      You can look for a local M&S Intercom Dealer at the Nortek website:

      If you are interested in looking into a replacement intercom, feel free to call us.

  19. Shing Kee Lau // November 1, 2016 at 9:43 pm // Reply

    In 1997 I built my house in Sydney Australia. The builder installed a M & S System ( MC608) for me. Recently the system don’t work. I want to instal a new intercom system to replace the old one. Could you please tell me what is the name of the company which can instal M & S System intercom in Sydney.

    • Unfortunately we don’t have a list of installers to refer you to, but I suggest doing a Google search for a residential intercom installer in your area.

      • Naresh Datt // November 2, 2016 at 9:57 am //

        Do you know any one who can replace chime module On IMA-4006 NuTone intercom???

        Sent from my iPad


      • Naresh Datt // November 2, 2016 at 9:58 am //

        Sent from my iPad


      • Naresh, we can’t help you replace an old part, but we can help you replace your system or troubleshoot problems. If you need either of these services, please feel free to reach out to our tech support department.

  20. I’m looking to replace my old nutone with a system that is compatible with the Ring Pro Doorbell. Any ideas?

  21. What we have been recommending is replacing your existing intercom with an IST Retro Intercom then adding the Ring Stick Up Cam to the front door. By adding the Stick Up Cam you wil be notified when someone is at the from door by the motion alert. And you will be able to talk to them using your smartphone if you are away from home.

  22. Seems to me that the ultimate solution to renovating an intercom system these days is a wireless radio system–it may use the same wall niches but it would connect the stations around the house over the air. What is available to bring the intercom into the 21st century?

  23. Richard Blood // January 8, 2017 at 3:13 pm // Reply

    How many wires are used with the IST retrofit system?

    • The IST Retro uses only 3 wires so it can replace existing 3, 4, or 6 wire intercoms. As long as there is 3 wires home run from each room, patio or door station to the master station, the IST Retro will work. Some of the older Nutone systems were wired in what is know as Daisy Chained in which the wire bundles are looped from each station to the next. If you have daisy chained wiring the IST won’t work.

      • Richard Blood // January 9, 2017 at 11:46 am //

        Thank you for your reply Bob G. I did run each set of 6 wires individually to each station so thank goodness for that.

  24. Joy triplett // February 3, 2017 at 5:19 am // Reply

    I have a nuton scovill someone messed with wiring .it just buzzes when turned on.its a tr 10could someone help.need a price quote.

  25. Diane Lyn Holowinski // July 5, 2017 at 1:31 pm // Reply

    I have a NuTone Scovill Model ST-1000, The Tune button is hard to turn and when I use the cassette player, the tapes get jammed. What can I do to fix these problems?

  26. Nutone no longer repairs these older systems as the parts need to repair them are no longer made. I would recommend you consider replacing the intercom with a newer intercom. You can see the different replacement intercom systems we carry by following this link:

  27. Hoping someone can help. My house was built in 2004 and I have a MS 602. Our system works fine, but a handyman lost one of the radio buttons replacing our backsplash, so I want to find a replacement button. I would had to have to replace the whole system over a cosmetic issue. thanks!

  28. Hello LMV, Sorry to say but replacement parts for your intercom are no longer available from the manufacturer Nortek Control. Your best bet would be to search eBay or other internet sites for used M&S intercom parts and see if you can find a replacement button there. Best of luck!

  29. Steve brodeur // February 22, 2018 at 12:57 pm // Reply

    We have a NU Tone audio and intercom system.Looking to replace audio system.

  30. We have a replacement intercom called the IST Retro that can easily replace your Nutone intercom. You can see the complete system on our website by clicking the link below:
    Feel free to contact me directly for additional questions or for a quote:, 800-266-8765 x 107.

  31. I have a 1m 4006 intercom system that needs a new patio speaker. Is that possible?

  32. The replacement parts for the Nutone IMA4006 are no longer available and the current version of the patio Nutone stations are not backward compatible. You may be able to find a used patio station online. We sell a replacement intercom system that uses the same wiring as your Nutone and can be installed without having to do any drywall repair. For more information look at the IST Retro Intercom:

  33. Pat Matevey // May 9, 2018 at 6:45 am // Reply

    After searching and searching For repair and installation in Miami Florida we used Master Electronic Specialilties-Nutone. They were excellent. 305 279-2215. Good luck.

  34. Patricia Byczynski // June 21, 2018 at 7:45 pm // Reply

    One of the wall units has started to hum (a couple different tones, loud then a lower tone.) I am fearful of going to bed for fear it might be electrical, however, I don’t think it is. It is like a vibration and when I touch one of the long bars on the side it seems to be more quiet. There is a wire which is loose and I don’t want to attach it to the screw on the panel for fear (again ) that it might be electrical. Can you help decide how to handle this. Thank you

  35. You didn’t state what brand your intercom is but in most cases the individual room stations can be turned off locally by turning the volume all the way down until the knob clicks off. Otherwise, you can disconnect the room station. These are low voltage system except where the Master Station in connected so electrical hazards at the room stations are unlikely. If possible you should have a local repair person come take a look at your system.

  36. Suzy katona // July 12, 2018 at 7:23 pm // Reply

    Your post is very helpful!

  37. Hi, I have old M&S system on my wall, which sized 8″X16″, how can I updated to the new machine with door bell and Bluetooth in same size? Thanks

  38. Must important to do now. Great article.

  39. I have an old M&S that partially works and am thinking about just using the locations to install a wireless video monitoring system. Remove the hardware leave the wiring and just use the existing wall opening to place modern wireless video & sound devices that I can swap out as technology changes. The options suggested above all sound like old technology slightly updated.

    • Zackary Forrester // February 17, 2020 at 11:15 am // Reply

      Hi Minghua

      Wireless is an option. In our experience, we have seen the wireless frequencies that current wireless intercom systems utilize are too close to other technologies within the user’s home and would suggest wired to limit interference and callbacks. If trying to upgrade to newer technology, there are limitations with the 3,4,5,6,7 or 8 conductor wiring and the step-down transformers that were utilized in the older intercom systems. Please note, if upgrading to a wireless system of your choice, disconnect the step-down transformer that feeds power to your master station.

  40. I have nutone system Im-3303. Problem when I push fm switch on face am shows instead of fm. Could you please help me with this problem. Thank You John

    • Zackary Forrester // February 17, 2020 at 10:57 am // Reply

      Hi John

      Unfortunately, NuTone has closed its line of intercom systems and support and troubleshooting literature is not available for that model. At this time, the recommendation would be to send our Tech Support team an email so they can help find you replacement options. They can be reached at

  41. Please help me if you can. Thank You John

  42. We have an old broan kn600 with a cd player attached ,i cant find the manual .We are selling the house and I need to fix or replace it ,Can you suggest a replacement please ..

    Thankyou Gerry

  43. joan stallings // April 2, 2020 at 8:54 am // Reply

    how large is the hole in the wall behind old old nutone intercom/radio?

    • Zackary Forrester // April 6, 2020 at 7:53 am // Reply

      Hi Joan

      The metal rough-in box is roughly 14-1/2 x 5-3/4 x 3-1/4 inches. The hole behind the intercom is normally 6″ deep. To ensure the sizing, you would need to have someone remove the master station and measure.

  44. Dick Culpepper // November 21, 2020 at 6:36 am // Reply

    I purchased my home in June, 2004. I have a Model Number MC111DM, The only thing I get is static. No Voice trasnsmition. What are my opinions? I have worked on electronic circuits before and was going to start changing out components. The first I would start with would be the capacitors because they are the usual components that go bad. Does a circuit diagram exists?

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