There is no hot water in my master tub. The cold works fine but when I turn it to hot, the water remains cold. My house was brand new when we bought 2 years ago, but we never used the tub before. What is wrong?

So this is the very first time you have drawn hotwater from this tub, right? Normally we look for clogs of debris in the mixing valve but being brand new complicates it a bit. Behind the tub, possibly in the next room or in a clost, is there an inspection hatch on the wall? A picture of the mixing valve would be good but brand and model even better, any chance of either?

Also, since it is not used (? You never used the master tub in two years of living there? )

But OK, first is it even turned on ? But it is possible it is merely clogged

Hi Rebecca...

I hope you at least used the cold water in the tub over the last two years... ;) If you've never used water in the tub then the PTRAP that keeps sewer gasses from entering your home definitely dried out... not a great thing! You want to get in the habit of using this tub valve at least once a month... wets the trap (keeps sewer gassses out) and keeps the valve parts from seizing up... that kind of stuff.

With all that being said, you definitely need to determine if hot water is even flowing to the valve.

Here, I would start by looking for a shutoff behind an access panel as Ballenger indicated. If no shutoff there, next I would have you remove the valve handle and trim around the valve and check to see if there are "integral shutoffs" (slotted screw heads) behind the trim plate... if so, open them full open counterclockwise.

If that dosen't work then most likely you will need to disassemble the valve and inspect/replace the valve cartridge as needed.

Back to you here...

Mark

Just to clarify, is this a single handle or two handle faucet? You say when you turn it to hot, it just stays cold, so I assume you mean there is water coming out of the hot, just cold water out of the hot? If it is indeed a single handle fuacet, you may merely need to adjust the anti-scald device(usually located directly behind the handle). This will allow the handle to turn further into the hot position, allowing more hot water. Let us know how you make out.