In our downstairs bathroom we have no hot water coming out of the bath tub. The sink works fine but it never gets hot at all in the tub. In fact when you turn it all the way to hot it ends up turning way down & almost no water comes out.

Any ideas on where to start?
Thanks for any advice.
Melissa

I suspect you have a mixing valve blockage at the cartridge. Describ your tub faucet in detail, brand and model if you have that info.

It is a single handle- Moen faucet- not sure of the model #. It is fairly new 1 1/2 years & to be honest we haven't used the bath tub because we have 2 others in the house so we never used it to check the hot water. I had just checked it because our water pressure upstairs gets fairly low when you turn it all the way to hot. But they still work upstairs not sure why this one won't run hot at all. Does this help or do you need more info?

You should read this site and try some of their tutorials. I think you are in the market for a 1225 cartridge. Installation Help / Animated Tutorial - Installing the Moen 1225 / 1200 Cartridge (http://www.moen.com/consumersupport/installation/moen0133/moen0133.cfm)
Don't forget to shut off the main. Once you pull the cartrdige you may be able to clear the hot line on the left soide of the cartridge, if not Moen gives a Lifetime warranty of their stuff, call customer support for your feebie.

our water pressure upstairs gets fairly low when you turn it all the way to hot.

Suggest that you flush water heater. Then remove cartridge in all valves and flush hot line.

It certainly is possible to have a blockage in the hot water lines, given the pressure has dropped in the other faucets. It may be necessary to remove each valve and flush the hot water line individually. Start with the tub giving you the problem though.

I agree. I just gave you the cure for your current issue but flushinh the heater may give you more time before crud cloggs your valves. Flush the tank by leaving the main on full pressure and open the drain spigot at the bottom of the tank. Most folks should attach a garden hose and run the water outside or to a floor darin, be careful its likely 12o degrees.