Help with shower shut offs/poor hot water pressure

[GLMhelpfix]

Hello all,

Just finished a new water heater install for my girlfriend's folks, and the already poor hot water pressure in one of their tub/showers dipped even more to make it near unusable. Rest of the hot water throughout the house is fine, this bathroom is midway through the line, sink in the same bathroom is great.

I opened up the mixer valve, checked the cartridge which is fine, and ran the water without the cartridge in to verify the pressure was bad at the supply, which it was (less than half of the cold, and it's about equal in the rest of the house).

There are what look like flathead shut off valves on either supply, but I can't get either of them to move even a little bit (photo below):



The shut off's had these fittings threaded in with washers behind them:


And behind those was some kind of black compound set in:


Which I carved out on the hotline to see if that freed up the valve at all, which it didn't:


I can't tell if the valve stem is supposed to rotate inside that fitting, or if it's supposed to rotate in the threads? I can't get even a slight budge out of it, and don't want to reef on it any harder until I have another rough valve body ready in case things go awry and I'm not leaving the whole house without water. I've already tried cranking on it pretty good with a pair of channel locks. The whole setup of it has me stumped, but my suspicion is that the hot valve isn't opened all the way or that's were the obstruction is lodged.

Would really appreciate any advice/points in the right direction, thanks much!

 

[Jadnashua]

You could get some PBlaster, spray some on and leave it maybe overnight. GIve it another shot and see if that helps break things free. Don't know for sure, but if there's any rubber component in there, heating it would destroy that. It might allow it to free up, and then you could replace those bits.

THose things come in two flavors, 1/4-turn where the slot indicates whether they are open or not, and a valve and seat that may have multiple turns where the slot has no meaning. It probably is a multi-turn valve.

The valve body looks like bronze which is good. But, if they used any galvanized piping to supply it, that could be full of rust, blocking off significant amount of flow because of the diminished diameter.

 

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[GLMhelpfix]

Thanks, I'll definitely give the PB a shot. all the hot supply line seems to be done in copper which is nice, but the old water heater was quite past its expiry so there could be rust from there, also they're off of a well that's pretty heavy in sulphur so that creates some mineral buildup as well, so who knows what I set loose when I redid the system.

 

[LLigetfa]

You might try an air compressor with a blow nozzle to try to blow the crud back toward the water heater and then hopefully wash it out through another fixture between the water heater and the shower.

 

[GLMhelpfix]

Well, no luck trying to backflush it with air, and penetrant and a heat gun did nothing for loosening the shut off. Is there any chance those arn't shut off valves and are just sealed up ports for a two handled system?

Realizing now that it being worse since the heater swap is probably from the new heater being set to a lower temp, meaning they've been turning it farther to hot and getting less flow from less cold mix, but still doesn't explain why it's so bad in the first place.

 

[James Henry]

Get the exact size screw driver that will fit those slots, even if it means you have to go buy one.
Put a small pipe wrench, ( 6") on the shaft of the screw driver and try to turn the stem.
" WARNING" IF YOUR AFRAID TO BREAK THE SLOT ON THE STEM. DON'T DO IT !!!!!

 

[Sylvan]

You might try an air compressor with a blow nozzle to try to blow the crud back toward the water heater and then hopefully wash it out through another fixture between the water heater and the shower.

Wow AIR testing back to pressure vessel .

I wonder what formal education you have to suggest such a terrible anti ASME testing procedure

This kind of advice is why people are maimed or killed

Just in case you need a crash course in why AIR is not a great idea think of the following

Take two balloons and fill one with air and the other with water.

Now pop each balloon and try to imagine which one has a violent reaction and which one plops open harmlessly

 

[LLigetfa]

Wow AIR testing back to pressure vessel ...

First off it would not be an air test as I am sure he would not be able to form a seal between the end of a blow gun and the valve body and even if he did, he could not hold it there at high pressure. I think you're being a drama queen.

 

[Themp]

Any chance you can figure out the make(brand) of the valve? Does the cover plate for the tile opening have any markings. From the cartridge can you identify the maker? How does the valve work for diverting the water to the shower head or tub? Maybe post a picture of the valve with it all back in place.

 

[Sylvan]

First off it would not be an air test as I am sure he would not be able to form a seal between the end of a blow gun and the valve body and even if he did, he could not hold it there at high pressure. I think you're being a drama queen.

I guess you can easily explain why 15+ PSI of steam is consider HIGH PRESSURE and why 160 PSI or 250 DEG hydronic boilers are considered low pressure

I guess then you can also explain why when air testing a natural gas line in a 47 story building the test pressure shall not exceed 3 PSI?


As a DIY I know your educational background is beyond approach and the higher the pressure the more the likely the lines will be cleared huh?