Delta shower cartridge -- no hot water

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Seattle

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I installed a new shower in the upstairs bathroom. The cartridge is a Delta RP46074 for a Delta MultiChoice valve. When I turned on both hot/cold supply lines, there was plenty of cold pressure at the shower head but only a trickle of hot water.

I then shut off the supply lines, removed the cartridge, turned on just the hot supply and there seemed to be plenty of hot water flowing through the body where the cartridge fits.

I thought it might be the anti-scald hot water rotational limit stop on the cartridge so moved that to the maximum hot setting. That resulted in no hot water flowing through the valve. I then moved it to the minimum hot water setting and still no hot water. I'm still only getting cold water at the shower head.

Thought it was a bad cartridge so bought a new one today and have the same problem----plenty of cold pressure but no hot pressure.

I have this exact same cartridge on the downstairs shower and the pressure on both hot/cold is fine.

Any ideas?
 
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hj

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No, because what you are describing is "illogical" and therefore something unique to your installation, meaning that we would have to be there to do our own testing and evaluation. However, because of the 'pressure balancing' unit in the cartridge, if there were no hot water TO the cartridge, it would also shut off the cold water.
 

Seattle

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I sawed off the anti-scald ring to eliminate that from the equation. Installed the cartridge again, turned on hot water supply. Again, no hot pressure at all. Turned on the cold and again, cold water pressure was fine. Turned the hot supply on again and suddenly, I have hot water pressure (with or without the cold supply on).

So, for those that stumble upon this posting with the same problem, I have no answer as to what the problem was or what fixed it. I doubt the anti-scald limit was the problem as removing it didn't resolve the issue immediately. Maybe it was a vacuum lock or something.
 

hj

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quote; Maybe it was a vacuum lock or something.

In that case you discovered a new law of physics, namely, how to create a "vacuum or something" in a pressurized system.
 

Jadnashua

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The pressure balance spool valve may have been lodged to one end and all of the bumping cutting, etc., dislodged it. On many designs, though, it shuts both supplies down, not just one. Could have been some crud that eventually got flushed out.
 

hj

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IT is a "good" theory, (a stuck spool WILL shut down or restrict one side or the other), but probably not valid since you said you replaced the cartridge, which contains the spool, and it would be stretch to believe that you could get TWO bad ones, much less both of them bad the same way.
 

ainnle

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I installed a new shower in the upstairs bathroom. The cartridge is a Delta RP46074 for a Delta MultiChoice valve. When I turned on both hot/cold supply lines, there was plenty of cold pressure at the shower head but only a trickle of hot water.

I then shut off the supply lines, removed the cartridge, turned on just the hot supply and there seemed to be plenty of hot water flowing through the body where the cartridge fits.

I thought it might be the anti-scald hot water rotational limit stop on the cartridge so moved that to the maximum hot setting. That resulted in no hot water flowing through the valve. I then moved it to the minimum hot water setting and still no hot water. I'm still only getting cold water at the shower head.

Thought it was a bad cartridge so bought a new one today and have the same problem----plenty of cold pressure but no hot pressure.

I have this exact same cartridge on the downstairs shower and the pressure on both hot/cold is fine.

Any ideas?
I have same problem new installed Delta shower no water from hot side. Called Delta sent me a new cartridge this time no water except a few drips. if I wait a minute it starts coming out faster and faster. After 10 minutes of letting it run it now works fine.
 

Homeowner Mark

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been having the EXACT same experience....plenty of cold but very little hot. plenty of water without cartridge in...but water won't allow more than warm water otherwise.
 

DIYer93

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Had this exact same problem with a Delta shower/tub faucet. Installed the cartridge and opened shutoffs. Cold water was full blast, but hot water was only a trickle. Reversed the cartridge and the hot water was full blast, but no cold water. Thought cartridge was defective so exchanged for a new one. Same thing. I agree that there's a very low probability that 2 new cartridges are defective so I removed the cartridge popped out the insert. I shook it several times and reinstalled it. I turned both hot and cold water back on and turned the lever. Voila, now I have both hot and cold water. Evidently the pressure balanced spool was the issue. Hope this helps.
 

tireflat

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This is the answer I found on the Home Depot forums and it worked for me:



Hey Laura, I just wanted to clarify, If you replaced the entire cartridge you should have the new model (RP46074) which (aside from the stem that comes out) is all plastic. If this is the case, you would turn the Rotational Limit Stop Counterclockwise. However, if you have an old cartrige (pre 2006) where there is a toothed brass ring with a plastic limit stop that fits on top of the toothed part you would need to turn the Rotational Limit Stop clockwise to adjust the temp up.




I hope this clears up any confusion. :smileysurprised:




-Blake


http://community.homedepot.com/howt...er-Repairpressuretemp-problem-9065000000007sy


This solved both of my problems. The handle fully turns and I get hot water. Since Delta discontinued the old cartridges, why couldn't they have told us of this, I can't fathom.
 

jkoch53102

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Just survived a deep freeze (7 degrees F) here in Austin. Wanted to add an observation I had regarding the trickle of hot water I was getting from the hot side of my shower faucet. During this freeze event the city lost water. In the start we could see the gradual loss in our water pressure as the city lost its main water plants due to multiple main bursts. This is when I found that the shower wasn't working. I could get some flow on the cold side but as soon as the valve crossed over onto the hot side the flow dropped to a trickle. So, the question I have is does the pressure remain high in the hot water tank after the pressure in the supply line from the city drops down? If so, this would cause the delta cartridge in my shower to lower the hot water flow rate to balance to the cold side? Note, shower works fine after the water supply from the the city was fixed.
 

Jesse Twichell

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I had the same problem and it took me a while to realize that the pressure balancing system automatically shuts off the hot water if the cold water is shut off. I was trying to test the pressure independently with each shut off valve turned off and the dang cartridge outsmarted me.
so the way to test it is to make sure both hot and cold are turned on and just run the water for a minute with the knob turned to cold and then to hot.
 

Tuttles Revenge

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So, the question I have is does the pressure remain high in the hot water tank after the pressure in the supply line from the city drops down? If so, this would cause the delta cartridge in my shower to lower the hot water flow rate to balance to the cold side? Note, shower works fine after the water supply from the the city was fixed.

Water pressure should be equal on both sides of the tank unless you have a hot water recirculating system with check valves that prevent the heated water from entering the cold system. A properly built recirc system would also have an hot water thermal expansion tank, which would likely account for the delayed decrease of water pressure on the hot side as the tank would hold some water and retain pressure for a minute or two.
 
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