No hot water from shower!!!!

Hello, I've got a problem with my shower water temp. When I turn my shower on and turn the knob to all the way hot it produces nice hot water for about 2 seconds then turns to luke warm. Sometimes it won't even go hot for the few seconds and just gets Luke warm immediately. All the other faucets in the house produce nice extremely hot water. I have a moen single handle moentrol faucet. The push/pull kind. I have take. Out the old cartridge and replaced it with a new one to no avail. Still Luke warm water at best. I've read about a scald guard and adjusting it but have no idea where to find the scald guard. Is that just another name for the cartridge that I replaced? If so, how do I adjust it. If not, where the heck is the scald guard?! Iv also tried rotating the cartridge 180 degrees and that just made it so cold is the the left and hot to the right when rotating the handle. If anyone knows what I'm talking about or has experienced the same problm and was able to fix it... Please help!!! Thanks ahead of time!

Mike

Sounds like it's the scald guard or you have the hot and cold reversed in the wall.

The scald guard on the newer Moen's is just a limiting screw inside the handle assembly. It's adjustable with an allen wrench.

It's definitely not a newer moen. The house is 40 years old. Not sure how old the actual shower and parts are. Where exactly is this Limiting screw? Is it in or around the cartridge? I don't see anything that takes an allen key or wrench. Ugh I really hope someone can help me out. I'm so sick of luke warm showers!!!

If the valve is 40 years old, it almost certainly doesn' have the scald gaurd feature. Maybe some of the more experienced service guys here might know of some valves from that time period that came with this, but it wasn't mandated until, I believe, 1994.

Did this just start happening, has it been a gradually worsening problem, or has it done this since you bought the place?

Do you have galvanized pipe?

If it's the pull on/push off type and you have replaced the cartridge, the next thing that comes to mind is debris in the line or valve itself.

The problem started about two months ago. Don't know if it's a coinsidence or not but it started when it got cold outisde (live in south Florida). Before this we never had a problem with the hot water in the shower. Yes the pipes are galvenized. I know the bathroom was added on to the house so I'm not sure that the valve and piping is that old. Why do you think it goes hot for a couple seconds then cools off? I don't get it! I'll take a picture of the valve assembly later today and post it so you guys can know exactly what I'm working with. Thanks again for your help!

Mike

If the valve is that old, I would recommend a full replacement. You may have some galvanized pipe corrosion impeding the flow of hot water, so flush the line before you add a new valve. It may cost a few extra bucks up front, but it will certainly solve your problem once and for all!

I would reccomend shutting down the water supply and draining it, then pull the cartridge. Shut the water heater supply valve off, then have someone turn the water on and then back off while you watch in the bathroom. Then turn the water heater back on, and have them turn the water on and then back off while you watch again. You should notice the there is considerably more flow with the water heater on, as both sides of the valve are getting fed at that point. If not, you have a restriction in the hot water feed to the valve. Maybe you will even get lucky and this will flush it out.

A word of caution, a tub valve can flow an impressive amount of water without a cartridge in, so make sure that whoever is turning the water on and off can do so quickly, and be prepared to clean up a bit of water on the bathroom floor.