A plumber just replaced the cartridge on a 15 year old Delta Multi-Choice 13/14 because the rental was just vacated and the tub and shower flows were lower than any other fixture in the house. Tub spout and Shower pipe flows were at 1.5 gpm and 0.75 gpm respectively. I tested it again with the new cartridge and the flows were the same --- very slow. Water pressure at the main water valve is 50 psi and flow at adjoining hose spigot is 8 gpm. There is only one bath in the house and the bathroom sink flows at 3gpm (both hot and cold separately) without the aerator. Utility sink next to the washer flows at 6 gpm (both hot and cold separately) without the aerator. I expect there to be some general flow reduction to corrosion of old 3/4 and 1/2 inch galvanized pipe, but all fixtures, except the bathtub, function adequately. The bathroom is plumbed with 1/2 PEX to both tub and sink, and by process of elimination it seems that the significant bathtub reduction is due to the Delta cartridge. Are the cartridges' designed to function as low flow governors? If so what is the minimum incoming flow to ensure quick filling of the tub and adequate shower head flow? Can a different cartridge be used in the RP46074 valve that allows a higher flow?
Low Flow in Delta RP46074
- Thread starter paulkirk
- Start date
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Flow is definitely impaired. You have blockage somewhere. Presume you are testing shower arm flow, not clogged shower head.
The first thing I would want to check is flow through the valve body itself.
Easy if the body has integral stops and two person job if no integral stops.
Unless you have wye strainers protecting the pex lines, you can easily have rust particles anywhere.
We always use wye strainers if customer can't repipe the entire system. Here is Delta flow rate chart.
https://www.deltafaucet.com/sites/delta/files/2019-11/Delta Flow Chart 2018-06-27.pdf
The first thing I would want to check is flow through the valve body itself.
Easy if the body has integral stops and two person job if no integral stops.
Unless you have wye strainers protecting the pex lines, you can easily have rust particles anywhere.
We always use wye strainers if customer can't repipe the entire system. Here is Delta flow rate chart.
https://www.deltafaucet.com/sites/delta/files/2019-11/Delta Flow Chart 2018-06-27.pdf
