Delta®

Stem Unit & Seats - 1600 Series

Model#: RP1991
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Delta®
Stem Unit & Seats - 1600 Series
Model#: RP1991
List Price: $69.85
Online Price: $55.88
Free Ground Shipping All Orders $49+
Add to Favorites
Find local Delta® installers.
PRODUCT FEATURES
Special Information
Warning Image
California Prop 65 WARNING
Special Information
Warning Image
California Prop 65 WARNING
Documents & Specs
Installation Information
Overall Height (in.) :
1-1/2
Valve Type:
NA
REVIEWS
Rated 5 out of 5 by from just as promised The parts came quickly and were just as promised. Installed quickly and did the trick.
Date published: 2010-11-22
Rated 4 out of 5 by from really reliable I am very pleased with the service. Could not find the right replacement. found your website, and it was a life saver. Otherwise, I would have had to replace the whole faucet... Thank You
Date published: 2010-06-05
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Q&A

Do you have an exploded view of all the parts for this faucet? I may need more parts.

Asked by: Anonymous
Hello, Thank you for your question about the Delta Faucet RP1991. An old catalog with parts diagrams of 1600 series faucets is available here: https://deltafaucet.my.salesforce.com/sfc/p/#A0000000KorJ/a/4Q000000St6n/GKQVHGOzfw6Awq5..5uossCuuuFJbQQJcqaipfXt_9s Please reach out with any additional questions! Best Regards, Bryan Digital Communications Specialist (800) 345-3358 customerservice@deltafaucet.com
Answered by: Digital Specialist
Date published: 2026-07-13

Is this the same as a 1691 cartridge?  

Asked by: Chris
Hello Chris, Thank you for contacting Delta Faucet Company! I am sorry this information was not readily available, and I am happy to help you! Our Delta Faucet Stem Unit & Seats - 1600 Series MODEL#: RP1991 is manufactured for our 1600 series, which has a single handle that rotates counterclockwise and has set screws at 5&7. Thank you for being a loyal Delta Faucet customer. We appreciate your business and look forward to continuing to serve you. Please contact us back with any further questions. Best Regards, Nicole
Answered by: Delta7
Date published: 2024-03-28

I have a Stem Unit & Seats - 1600 Series MODEL#: RP1991 for my shower. It does not have temperature control. Is their a replacement cartridge that will do this? Or, do I need to replace the whole valve to get this?

Asked by: Frank G

Is this for the old shower handle units

Asked by: harborman
Hi harborman, Thank you for your question! This cartridge was utilized on the 1600 series shower trim kits. Please contact us directly by phone at 1-800-345-3358 or email at customerservice@deltafaucet.com if further assistance is needed at this time. Please reach out with further questions! Best Regards, Tim Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-01-31

What is the part # for the check valves for the 1600 series. If i try to turn the hot side of water off its leaking. Without turning the water off, I cannot take out the RP1991 Cartridge ? And these are for commercial use, are they covered under warranty?

Asked by: Ilwingate
Hi IIwingate! Thank you for your question! The part number for the check valve stop assemblies for the 1600 series shower unit is RP16213. If used for commercial use they would only be covered by a five year warranty. Best Regards, Tim
Answered by: Delta
Date published: 2024-03-28

I also need the springs for the RP1991

Asked by: RRobin
Hi RRobin, Thank you for contacting Delta Faucet Company! Please accept our sincere apology for the inconvenience you are experiencing. Here is what we can do to resolve your issue for you. Our Delta Faucet Stem Unit & Seats - 1600 Series MODEL#: RP1991 would take the RP4993 seats and spring. Please see the link below. https://www.deltafaucet.com/parts/product/RP4993.html Thank you for being a loyal Delta Faucet customer. We appreciate your business and look forward to continuing to serve you. Please contact us back with any further questions. Best Regards, Nicole
Answered by: Customer Service
Date published: 2024-03-28

Hi, do you know which Delta handle fits the 1600 stem unit. My old handle has an insert witch has 2 set screws

Asked by: Druid
Hi Druid, Thank you for your question regarding our Delta Faucet RP1991. The replacement knob handle for this stem unit is part number H71. Please reach out with further questions! Best Regards, Themar Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-07-01

How to increase the hot water temp. In the middle, it's very cold. Have to turn pretty much almost all the to the left which then reduces the pressure. Watched a few videos. I Turned the adj screw counter clockwise. That didn't fix it

Asked by: Fran
Hello Fran, Thank you for your question. We are happy to help! Adjusting the set screw on the cartridge will adjust the handle limit stop. We recommend flushing the valve with the cartridge, seats, and springs removed. Turn on the water supply for a minute with the shower door or curtain closed. It will shoot water across the shower and clear any debris that can be causing the issue. If the issue remains, replace the RP1991 cartridge. Please reach out directly if you have any questions or need additional assistance. Best regards, Bryan
Answered by: Delta Faucet
Date published: 2024-03-28

Are the knobs available for this (both the shower only, and shower/tub in the 1600 series)?

Asked by: Greg
Hi Greg, Thank you for your question about the Delta Faucet RP1991. A 1600 series shower can use handles from a 1400 series. Other replacement parts will not work. A knob handle kit is H71. A lever handle kit is RP48717. Please reach out with any additional questions! Best Regards, Bryan Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-01-31

I believe I have the 1600 series cartridge installed in my shower and the handle broke off. I'm having a hard time finding a replacement handle. Is there another series that's compatible with this cartridge?

Asked by: Stasia
Hi Stasia, Thank you for your question! For a Delta Faucet 1600 series faucet, any 1400 or 14 Series Shower Handles will work - but not the rest of the trim. See one example here: https://www.deltafaucet.com/parts/product/RP48717.html Please contact us directly if you have any additional questions! Best Regards, Bryan Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-03-28

Without disassembly how can I tell if I need rp-19804 or rp 1991 replacement parts?  Also do you have instructions for rp 1991?

Asked by: Charlie
Hi Charlie, Thank you for your question about the Delta Faucet RP1991. A 1600 series faucet would be made before 1993, uses this unit, and has the escutcheon screws at the lower left and lower right. A 1300/1400 series faucet would be made after 1993, uses RP19804, and has the escutcheon screws at the lower left and upper right. Please reach out if you have any additional questions! Best Regards, Bryan Digital Communications Specialist
Answered by: Customer Service
Date published: 2023-03-01

Is this the same as Delta 36004 Scald Guard Single Lever Cartridge?  Part/model # 36004?

Asked by: Deltashowerrepair
Hi Deltashowerrepair~ Thank you for your question and we are happy to help. This is not the same as the 36004. With any further questions or concerns, please do not hesitate to reach out to us again. Best Regards, Carrie
Answered by: Customer Service
Date published: 2024-08-20

Is there a video on how to replace the 1991 series 1600 cartridge and trim

Asked by: Nick
Hi Valued Customer, Thank you for your question! I have attached the parts link for the 1600 series for reference. Unfortunately, we do not a replacement video. First, please make sure that the water supplies are turned off to the valve. Remove the handle by removing the Phillips head screw on the front. If you have a clear knob handle, pry the cap off to get to the screw. Unscrew the bonnet nut. You should then be able to pull out the stem unit. You can scoop out the seats and springs using a pencil or Allen wrench. Best regards, Themar Digital Communications Specialist (800) 345-3358 customerservice@deltafaucet.com https://photos-us.bazaarvoice.com/photo/2/cGhvdG86ZGVsdGFmYXVjZXQ/970434df-bbaa-5e8c-891b-0817b13ade18
Answered by: Themar
Date published: 2025-08-07

is this part for a 1/4 turn volume only faucet

Asked by: john
Hello john, Thank you for your question. We are happy to help! The RP1991 cartridge is for a 1600 series shower valve. The 1600 series was made before 1993. It has no integral volume control and the temperature is controlled by moving the handle counterclockwise. Please reach out directly if you have any questions or need additional assistance. Best regards, Bryan
Answered by: Delta Faucet
Date published: 2024-03-28

What faucet trims are available to fit this cartridge?

Asked by: Miranda
Hello Customer! Thank you for your question and we are happy to help. The RP1991 is used for 1600 series showers. We do not make new trim kits for this model. with any further questions or concerns, please do not hesitate to reach out to us again. Best Regards, Carrie
Answered by: Customer Service
Date published: 2024-05-20

I have two showers that were installed when I bought my current home. Both use Delta RP1991 cartridges. Both were replaced (with RP1991) back in 2020 by a local plumber. What Single Handle Tub and Shower replacement do I need, and where can I get it?

Asked by: Allyn
Hi Allyn, Thank you for contacting Delta Faucet Company! We apologize for the issues you are experiencing and we are happy to help! Our RP1991 cartridge is used with our 1600 series. Unfortunately, we no longer manufacture tub/shower trims for our 1600 series valves. If you are seeking to update your tub/shower trim, the rough-in valve will also need to be replaced. We appreciate your inquiry. Please reach out directly if you have further questions! Best Regards, Kyra Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-06-26

After replacing my RP 1991 cartridge, the handle is at the wrong angle. It is at 2:00 position in stead of 3:00. Can that be adjusted?

Asked by: Steve
Hi Steve, Thank you for your question about the Delta Faucet RP1991. Unfortunately, the position of the stem in the off position is not able to be adjusted. The cartridge should be installed so that the key tab that fits into the brass valve is at 9 o'clock and the stop that prevents the brass from turning is also on the left. Please reach out with any additional questions! Best Regards, Bryan Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-05-15

can you provide a part number for the housing assy on the delta 1600 series. It sits inside the pipe in the wall and the cartridge connects to it by the gasket/spring. its a small plastic piece for the shower handle feature.

Asked by: JanC
Hello JanC, Thank you for your question! We apologize that the information you are searching for was not readily available. We realize that can be very frustrating and I am happy to assist you! We thank you for being a loyal Delta Faucet customer. The Delta Faucet part RP1991 Stem Unit & Seats - 1600 Series does not have separately orderable parts aside from the Delta Faucet part RP4993 Seats & Springs (2 Ea). We apologize for any inconvenience this may cause. Please contact us back directly via email with any further questions. Best Regards, Skyler
Answered by: Delta7
Date published: 2024-03-28

Besides replacing the Cartridge of Part # RP1991, what other recommended things to do to enhance the seal or improve performance?

Asked by: LittleOscar
Hello LittleOscar, Thank you for contacting us, I would be happy to help you. The only other recommendation is to flush the whole system, anytime you replace internal parts we always advise on a flush. Please contact us back if you have any questions or need further assistance.  Best Regards,  Nicole
Answered by: Delta7
Date published: 2024-03-28

What is the little screw on the side for

Asked by: Fran
Hi Fran, Thank you for your question regarding Delta Faucet RP1991! We apologize for any inconvenience you are experiencing, and we will be happy to help! The set screw on Delta Faucet RP1991 is the Rotational Limit stop for a 1600 series shower valve. Thread the set screw in to receive cooler water, thread the set screw out a little to receive hotter water. We look forward to better serving you in the future. Please contact us directly with any further questions. Best regards, Kyra Digital Engagement Specialist
Answered by: Customer Service
Date published: 2024-03-28

Hello, I have a Delta Shower that was installed over 45 years ago. It has started to leak and I feel the cartridge needs to be replaced. Can you tell me which cartridge is compatible with a shower from 45 to 50 years ago. Also, are there any instructions 

Asked by: Joe Mancini
Hi Joe, Thank you for your question regarding our Delta Faucet RP1991. We have reached out to you directly. Thank you for being a loyal Delta Faucet customer. Best Regards, Themar Digital Communications Specialist (800) 345-3358 customerservice@deltafaucet.com
Answered by: Customer Service
Date published: 2024-04-05

i have a shower in my apartment bldg that has low water pressure and it uses the rp 1991 cartridge. This apt is at the lowest point of the bldg. I have replaced the rp 1991 cartridge and the seats and springs but still have low water pressure .

Asked by: brendan
Hi brendan, Thanks so much for contacting Delta Faucet Company about, RP1991! Low flow is caused by a blockage or debris, we would recommend flushing the shower unit. I have included a link below to our Help Center with step-by-step instructions. https://support.deltafaucet.com/s/article/Flushing-a-Tub-Shower-Valve Please contact us directly if you have any questions or need additional assistance. Best Regards, Nicole Digital Communications Specialist
Answered by: Customer Service
Date published: 2023-05-04

I have a RP1991. Will the H79 lever fit? If so, what other parts will I need? Escutcheon plate part number? Thank you! 

Asked by: CourtH
Hi CourtH, Thank you for your question! We apologize that the information you are searching for was not readily available. We realize that can be very frustrating and I am happy to assist you! We thank you for being a loyal Delta Faucet customer. The Delta Faucet part H79 Metal Lever Handle Kit - Tub & Shower In Chrome is not guaranteed to be compatible with the Delta Faucet part RP1991 Stem Unit & Seats - 1600 Series as it is intended to be installed with the Delta Faucet 1300/1400 series or 13/14/17/17T MultiChoice (MC) series shower trims. We recommend using the Delta Faucet 13/14 MC shower trim for the closest compatibility. Please contact us back directly via email with any further questions. Best Regards, Skyler
Answered by: Customer Service
Date published: 2024-03-28

How do I adjust to make the water hotter?

Asked by: Valued Customer
Hello Valued Customer, Thank you for contacting Delta Faucet Company! Adjusting the temperature limit stop on this cartridges is as simple as screwing the allen screw located in the base of the brass stem of the cartridge in or out. Turning it to the right will reduce or eliminate travel of control into the maximum hot zone. We appreciate your inquiry. Please reach out directly if you have further questions! Best Regards, Kyra Digital Communications Specialist
Answered by: Delta
Date published: 2024-12-10

I built my house in 1990 and the Delta Tub and Shower Faucet is now just starting to leak. It looks like I need to replace the cartridge. Can I determine what cartridge it takes without removing it first?

Asked by: Davre
Hello Valued Customer, Thank you for contacting Delta Faucet Company! Yes, and we apologize for the issues you are experiencing and we are happy to help! We have reached out to you directly to further assist you with this matter. We appreciate your inquiry. Please reach out directly if you have further questions! Best Regards, Kyra Digital Communications Specialist
Answered by: Delta
Date published: 2025-01-09

What is the part number of the adapter for the handle of shower faucet to be put onto the stem of RP1991?

Asked by: Hong
Hello Hong, Thank you for contacting us, I would be happy to help you. The 1600 series does not have a handle adapter for the installation of the RP1991. Please contact us back if you have any questions or need further assistance.  Best Regards,  Nicole
Answered by: Delta7
Date published: 2024-03-28

Can I replace my rp 1991 cartridge with a newer balanced pressure cartridge?

Asked by: Steve
Hi Steve, Thank you for your question! No, you will still utilize the RP1991 cartridge unless you install a newer R10000-UN rough-in valve which utilizes the newer RP46074 cartridge. Please reach out with further questions! Best Regards, Tim Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-03-14

Is there a 1991 cartridge that is not a scald guard type? After replacing the cartridge and seats the water is only warm. It was much hotter before replacement.

Asked by: TomD
Hello, Please accept our sincere apology for the inconvenience you are experiencing. Please contact us directly by phone at 1-800-345-3358 or email at customerservice@deltafaucet.com as we would like to resolve this matter for you at this time. Best Regards, Tim Digital Communications Specialist
Answered by: Digital Specialist
Date published: 2026-06-20

How do I adjust it for more hotwater

Asked by: Coop

Hello. I currently use 1600 series with cartridge number RP1991. It's been leaking so I already changed seats and springs. although still leaking. is it possible to replace Rp1991 with other delta cartridges without changing valve set?

Asked by: mosen
Hi mosen, Thank you for your question about the Delta Faucet RP1991. Unfortunately we don't carry other shower cartridges that can be used in place of this cartridge or stem. Please reach out with any additional questions! Best Regards, Bryan Digital Communications Specialist
Answered by: Customer Service
Date published: 2024-08-22
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