mudslinger
Dec 2, 2011, 10:32 PM
Hi everyone, this is my first time on the site. I will start with a question, but hopefully I will also be able to help someone else.
I'm a bricklayer by trade but over the last ten years have done numerous renovations, and most recently moved a house onto a new basement. I've done most everything myself, foundation to finishing. Perhaps I should have hired more of the jobs out but contractors in the little town we moved to seem so expensive. Of course at this point with the learning curve I've had, maybe they aren't that expensive after all.
The problem: (there might be more than one) The hot side of the moen positemp (1222 valve style) in the bath/shower does not get as hot as the rest of the fixtures (faucets). The hot temp varies a bit, there are moments (seconds) when the temp is as hot as the other fixtures but then cools off. Sometimes the shower head seems to be hotter than when the water comes out the tub filler.
Solution: (I have tried more than one) First I removed the temperature limiter in case it was contributing. No change. Then I replaced the cartridge in case the pressure balancing mechanism or some other valve component was malfunctioning. Still no noticeable change.
One test I performed several times was to run full hot through other fixtures to test the temp and then run the tub/shower fully hot to compare.
While the valve body was clear of the cartridge I flushed the lines. Unfortunately no revelations there. The hot supply seemed lower pressure than the cold. This was also the case when the cartridge was installed. Upon examining the cartridge I observed the slot at the back of the cartridge (hot) is larger than the slot at the front of the cartridge (cold). Perhaps this is a design feature that increases cold pressure, or decreases hot pressure?
The other component I imagined could be a factor is the thermostatic mixing valve that was built into the system between the IWH (instant water heater) and the manifold of the "home run" system. I replaced it with a straight piece of copper. Now I figured this was almost the last resort, for sure even if this isn't contributing to the problem in the shower/tub, at least it would allow the temperature to all the fixtures to increase. However, to my surprise and disappointment... so far... still no change.
A little FYI, the domestic hot water is supplied by a Rinnai 94LSi instant water heater. I have some prior concerns about it, and wonder if it has issues that are contributing as well. For instance the temperature setting is 130 F, but I can't get more than 120 F at the fixture(even after removing the TMV as I just described) I'm planning on contacting them to see if they have any insight, or warranty solutions.
After removing and re-installing the cartridge several times (including a new cartridge), running the system with and without the cartridge, and removing the TMV... I'm coming to the conclusion that either the replacement cartridge is also faulty and allowing cold to mix with the hot, or there is a problem between the manifold and the fixture. But since it is a home run system that seems hard to imagine what problem that could be that would effect the temperature. I guess I'm no pro, but I would assume some kind of blockage in the line would really only reduce the pressure not the temperature. Am I wrong? Could a blockage, or reduced pressure also reduce the temperature?
Another condition that I wondered about, but I'm skeptical it would have a lasting effect, is the fresh air duct to the furnace is near by the water lines to the bathroom. Some of the lines may even be touching the cold air return ducting. Like I said, I'm skeptical that condition would cool off the lines for so long (I ran the hot water for close to 10 minutes during one test described earlier) and the lavatory fixture should be effected also since the lines are practically bundled together.
Well... I didn't intend to write a novel, so I apologize if I'm breaking some kind of chat room rules. This is literally the first time for me.
Anyway, thanks for any suggestions or other diagnostic tips. I will try a little longer to sleuth out the problem before I start cutting out the finished ceiling in the basement to run a new line to the mechanical room.
I'm a bricklayer by trade but over the last ten years have done numerous renovations, and most recently moved a house onto a new basement. I've done most everything myself, foundation to finishing. Perhaps I should have hired more of the jobs out but contractors in the little town we moved to seem so expensive. Of course at this point with the learning curve I've had, maybe they aren't that expensive after all.
The problem: (there might be more than one) The hot side of the moen positemp (1222 valve style) in the bath/shower does not get as hot as the rest of the fixtures (faucets). The hot temp varies a bit, there are moments (seconds) when the temp is as hot as the other fixtures but then cools off. Sometimes the shower head seems to be hotter than when the water comes out the tub filler.
Solution: (I have tried more than one) First I removed the temperature limiter in case it was contributing. No change. Then I replaced the cartridge in case the pressure balancing mechanism or some other valve component was malfunctioning. Still no noticeable change.
One test I performed several times was to run full hot through other fixtures to test the temp and then run the tub/shower fully hot to compare.
While the valve body was clear of the cartridge I flushed the lines. Unfortunately no revelations there. The hot supply seemed lower pressure than the cold. This was also the case when the cartridge was installed. Upon examining the cartridge I observed the slot at the back of the cartridge (hot) is larger than the slot at the front of the cartridge (cold). Perhaps this is a design feature that increases cold pressure, or decreases hot pressure?
The other component I imagined could be a factor is the thermostatic mixing valve that was built into the system between the IWH (instant water heater) and the manifold of the "home run" system. I replaced it with a straight piece of copper. Now I figured this was almost the last resort, for sure even if this isn't contributing to the problem in the shower/tub, at least it would allow the temperature to all the fixtures to increase. However, to my surprise and disappointment... so far... still no change.
A little FYI, the domestic hot water is supplied by a Rinnai 94LSi instant water heater. I have some prior concerns about it, and wonder if it has issues that are contributing as well. For instance the temperature setting is 130 F, but I can't get more than 120 F at the fixture(even after removing the TMV as I just described) I'm planning on contacting them to see if they have any insight, or warranty solutions.
After removing and re-installing the cartridge several times (including a new cartridge), running the system with and without the cartridge, and removing the TMV... I'm coming to the conclusion that either the replacement cartridge is also faulty and allowing cold to mix with the hot, or there is a problem between the manifold and the fixture. But since it is a home run system that seems hard to imagine what problem that could be that would effect the temperature. I guess I'm no pro, but I would assume some kind of blockage in the line would really only reduce the pressure not the temperature. Am I wrong? Could a blockage, or reduced pressure also reduce the temperature?
Another condition that I wondered about, but I'm skeptical it would have a lasting effect, is the fresh air duct to the furnace is near by the water lines to the bathroom. Some of the lines may even be touching the cold air return ducting. Like I said, I'm skeptical that condition would cool off the lines for so long (I ran the hot water for close to 10 minutes during one test described earlier) and the lavatory fixture should be effected also since the lines are practically bundled together.
Well... I didn't intend to write a novel, so I apologize if I'm breaking some kind of chat room rules. This is literally the first time for me.
Anyway, thanks for any suggestions or other diagnostic tips. I will try a little longer to sleuth out the problem before I start cutting out the finished ceiling in the basement to run a new line to the mechanical room.