Plumbing in the Home/Delta 1300/1400 shower valve
Josh at Delta Customer Service wrote at 2009-08-08 23:06:54
I worked at Delta's consumer warranty/tech center for almost five years, and recently transferred to the corporate office. I hope you've already resolved this issue, but if not keep reading.
When you emptied the valve body and kicked the water pressure back on, did you visually witness a solid and forceful stream coming out of both the hot and cold ports? I've seen cases where a home owner will have hydrant-like pressure coming out of one port, which can visually obscure a lack of pressure coming from the other port.
If there was forceful flow from both the hot and cold ports, and with the cartridge cap installed w/o the pressure balance housing (the back end of the cartridge) you still have low flow from the tub spout, then you definitely have some sort of blockage in the drop distance from the valve body to the spout.
The valve body cannot fail, as it has no moving parts. It is simply hollowed brass.
I would suggest backflushing the valve body. Remove the showerhead and cap off the shower arm. Remove the cartridge from the valve body. Remove the tub spout. Then force pressured air or water (no more than 100 psi) through the pipe to which the spout was attached. This should force the offending debris out through the empty valve body.
Ted wrote at 2011-01-27 22:35:57
I to have the same problem as Kurt. I did the same as kurt did and I have to think that the center hloe is plugged some how. We had good flow and it slowly lost pressure. I am looking for a way to put something like hanger wire in to see if that will help. I am stumped too. Did all steps above and the problem has to be in the pipe.
Theodore wrote at 2011-02-02 00:04:00
I am sorry to hear that you are experiencing a problem with your shower unit. It sounds like you need to backflush your valve assembly. The valve assembly does not become defective over time, debris usually builds up over time causing a restriction in flow.
* Turn off your water supplies to the shower unit
* Remove the valve cartridge and any internal parts or pieces, leaving valve open and empty
* Remove your shower head and tub spout from their supply lines
* Cap the pipe connection going to the tub spout (if applicable)
* Attach a garden hose to the pipe going to the shower head
* Turn the water supply on to the garden hose and backflush the valve body
* After the valve has been backflushed, turn off the water supply to the garden hose and disconnect the hose from the shower head supply line
* Uncap the tub spout pipe connection (if applicable) and reattach the tub spout
* Flush water thru the main valve body prior to reinstalling the cartridge assembly and/or any internal parts
* Install internal parts and test water connections
* If the water supply is good thru the shower head, reattach the showerhead to the supply line
dandi wrote at 2013-06-26 03:14:34
My Delta single handle was the same way. I took cartridge out, capped shower head, removed tub spout and blew compressed air up the tub pipe and lots of rust particles came out open valve body and into tub. This fixed my problem, but I also think there is an easier way to do it now that I know what the problem is and how the valve functions. Once the cartridge is removed you will see the two water inlets at the back of the valve body and above them is another opening with a copper tube running up and down through it. I think with an extending magnet tool you could reach into the opening and try to pick up rust particles at the bottom of that opening and around the pipe. This would have been much quicker and easier.