We've been in our house 6 months, a new build, and haven't used jacuzzi tub. Just discovered yesterday that cold water has plenty of pressure. Hot water has maybe half that of cold for about 20 seconds then goes down to about a tenth of the volume of the cold water. WTH is going on here, something in line that is getting pushed up to the valve?

Edit for update. I turned water off to unscrew the hot water valve, one on right in picture. Only the handle screws off. When I turned water back on, the hot barely comes out at all now. Has to be an obstruction, right? The water lines are flexible tubing.


I can't get pic smaller from phone.

[This message has been edited by Potcake (edited 3/23/2013 10:37a).]

Check the easy stuff first.

Do you have an access panel to get to the water supply under the tub? Check and make sure that the supply valves are turned all the way on.

With the diminishing pressure I doubt that's your problem but it won't hurt to try.

After that you'll probably need to take the cartridge out of the hot water valve. It varies by manufacturer but once you take the handle off you should be able to figure out how to remove it.
Check to see if there is crud in it or if the o-ring is buggered up.

If there isn't anything obvious see if you can swap out the hot and cold cartridges and see if the problem follows the cartridge and then you know it's bad. Take it to the parts house and get a replacement.

ddp

[This message has been edited by 87IE (edited 3/23/2013 10:59a).]

Use your warranty. Curious, did you get an inspection done?

Thanks 87.
TXAGFAN, yea we had two inspections as well as the City of Austin inspections. The builder told us to call his plumber, I just thought I would try and avoid the hassles of scheduling and waiting.

Changing a cartridge is not hard. Probably easier than the schedule hassle. Pull the old one and go to hd or Lowes with it. New one should be pretty cheap. Swtching is a good test too. If that doesn't fix it, put the old one back in, call the plumber and do the say you tried to fox it.

Could be the pressure regulator? I had a cartridge issue a couple months back and was a HUGE pain in the ass. No one carried it and then after I replaced it found out I had a pressure regulator/dealie-whopp that needed to be replaced. This was an old fixture and it was a huge pain.

Another thought.... Hot line in tubs in newer houses often has an anti scald mixer valve somewhere. This valve mixes in cold to regulate the hot temp. I suppose it could clog or contribute to the problem possibly.