Good day gents.. Searched a lot of posts on here and elsewhere to no avail so hoping you could shed some light on a problem that recently developed with my upstairs 'master' shower. This is an addition built in1982 to the rear of the original house that was built in 1949 on concrete slab. I wasn't here when the addition was done. 1/2" copper piping is used though out and the 'new' water lines were run in the ceiling thru the old house to the addition which is now the floor of the master bedroom and ensuite. The shower hadn't been used/idle for about a month (being ill and then away then using the downstairs tub instead) and recently when getting back into the shower I noticed a considerable drop in the cold water. The hot is ok. It an older Delta (Deltique) Series 800 shower faucet and I've thoroughly cleaned the shower head. In my readings I thought it might be the cartridge, so I sourced out a new one and finally got to replace it today. When I removed the original one I was hoping to find maybe a deteriorated rubber seat or gunk in the assembly but it was in good shape, no gunk and the seats were intact..just a little flattened but otherwise ok. I put in the new cartridge and seats anyway but no luck on the pressure issue. I fiddled with the cold water pressure balance screw on the right of the cartridge but that is open completely and the volume stem below the cartridge functions normally but doesn't improve Cold water flow. So now I'm stumped and figure there must be some blockage in the cold water line that feeds the faucet somewhere. There's a bidet next to the shower, and a soaker tub next to that with a double sink on the opposite wall. Both hot and cold are fine in these fixtures.
Any ideas on what could be the problem.. or will I have start opening up floors and walls...?? Ugh...
Thanks for your assistance.....

 

Before cutting open the walls I would turn off water to the house. Then shut off the water to the water heater so the house can only get cold water. Remove the faucet cartridge and turn on the water to the house for 20 seconds. Hopefully this unrestricted flow will flush out anything clogging the line. If the flow is reduced, while the water is running open and close the service screwdriver shutoff's on the faucet body several times. The opening and closing may crush the obstruction and let it pass through.

 

Thanks Pilot Dane.(tak for det).. Working on the issue and did as you suggested below..and it didn't work unfortunately...however I think what that did do was confirm (I believe) that there is no obstruction/blockage in the pipes. With the HW off at the tank and the cold water on at the main, I shut off /tightened down the cold water (right) service screwdriver shutoff on the faucet body..(I know the HW is ok..) and removed this larger flat screw to reveal this 'thing'. I backed off the screwdriver shutoff and water came charging out thru the CW screw shutoff and the hole from the 'thing/regulator'...I'll call it. I removed the inner portion of the regulator, replaced it, backed off the screw shutoff and water came flowing out of both the HW and CW holes in the faucet... So that how I figured that the water flow to the faucet is good but something is out of wack with this 'regular'. When I put its insert back in and reinstalled the regular.. I'm back to the original problem..being hardly any CW pressure. So the problem must lie there...somehow. It seems clean, no crud or buildup but I have it sitting in some vinegar right now as I'm writing this update. Maybe this 'regulator' is supposed to 'float' and move back and forth to regulate the hot and cold water and is not sliding anymore......!?! I don't know...but at least I know that the pipes are not the issue.....Ugh..
Thanks again for your assistance....
PS. I have the Installation Guide for this faucet..Delta 824,828 and that 'thing/regulator' is the Balance Spool Assembly (part #574)... the search continues. It's in vinegar right now..but I don't see anything wrong with it...?? ...
regards




ds

 

..A further update....
After cleaning the spool assembly I put a film of plumber grease on the piston (inner piece), installed the whole assembly. That didn't do anything. Removed it, cleaned of all the grease etc and re installed it. That too, didn't do anything. No improvement to the water pressure. I removed the whole thing, removed the piston and re installed only the assembly/cylinder. Pressure is good, but no hot/cold...just warm. Not able to increase the Hot or Cold.. Soooo, what now...UGH...!!

 

Todays update to say that I finally got the fix. Apparently it was the Balance Spool Assembly. I shut down the water and removed the sleeve/cylinder, placed the piston in the cylinder with the holes kind of lining up tho they weren't really even with each other, applied a little grease to the O rings and reinstalled it. I left a CW sink tap opened a bit and turned on the main. Went upstairs and turned on the shower and low and behold...Voila.. Cold water..with pressure..and HW with pressure and able to mix the 2. I'm so excited it works. After process of elimination it had to be the Balance Spool.. Why it didn't work the 1st time I cleaned it....who knows...!?!
Thank you PD for your suggestions in helping narrow things down...