View Full Version : Hot Water Issues

Keith Starosta
03-09-2005, 7:02 AM
Being that I am even more of a novice at plumbing than woodworking (which is saying something!! :eek: ), I have no idea how to solve my most recent plumbing mystery, so I will turn to the collective knowledge here. The problem is in the 2nd floor hallway bathroom, specifically the hot water in the shower. Normally when we turn on the HOT, it takes a minute or two for it to really get steaming hot. For the last week or so, it will barely get luke-warm, after letting it run for up to 15 minutes! I don't think that it is an issue with HOT getting to the second floor, as the master bath is just fine, as is the HOT in the sink in the hallway bathroom. Any idea what might be the issue, or something I may want to check?

TIA, folks!!


Jeff Sudmeier
03-09-2005, 8:05 AM

If you have hot water in the sink, but not the shower, in the same bathroom. The problem is between the sink and the shower. Some of the newer shower heads have safeties in them so that you can't scald yourself. It may be possible that this failed and replacing the head would solve your problem?

However, if it is really a bath tub and the water out of the faucet is cold as well, then I don't know. Must be in the supply from the sink to the Shower.

David Wilson
03-09-2005, 8:38 AM
How old is your house? If it is more than 20 years old you might have calcium build up on the inside of galvanised pipes. I had this problem and solved it by replacing pipes with copper.

Karl Laustrup
03-09-2005, 8:42 AM
You don't say whether you have individual hot/cold handles or a single blending type. If it is the single type that blends the hot/cold, I'd be thinking that it's the culprit, based on the other info you've given.

Bob Hovde
03-09-2005, 8:45 AM
If it's just a shower (no tub), there could be an anti-scald provision in the handle mechanism, rather than the shower head. The insides of the handle mechanism can be replaced.


Mike Cutler
03-09-2005, 12:04 PM
One more thing to check; In addition to overtemperature and anti-scald features, you may have a pressure equalization/compensation valve. My Grohe Thermomix does exactly what yours does when the internal filters get clogged and the pressure differential between the cold and hot inlets gets too high. There is also a bimetallic strip temperature control mechanism that could be causing problems. I guess that was two things

Chris Padilla
03-09-2005, 4:49 PM
We have the same issue...it is the mixer in the shower that was our problem. A real pain to replace but it solved the problem.

Keith Starosta
03-10-2005, 8:29 AM
Thanks for all of the replies, guys. I took the shower head off and there was a bunch of gunk all built up in the head. My wife has been wanting to replace the thing anyway, so I'm going to take a good detailed look at what is happening.

I know you'll all be waiting with anticipation for my results!! :p

Thanks again!


Ray Bersch
03-12-2005, 9:45 PM
Well, its Saturday night and perhaps you have already started to tackle the problem - however, you won't fix it by changing the shower head - the water is already mixed by the time it hits the shower head and shower heads are designed only to limit the amount of water flow, not the temperature of the water. The gunk in the head may be the major clue, however, because that is probably what is blocking the mixing valve so that is the most likely culpret. Changing a mixing valve may not be to your liking. Many have no easy access. Often some tile has to be removed from the shower or perhaps the sheetrock cut out from an adjoining room wall - and then you need to be good at using a torch and solder - first you have to get the sucker out then sweat in the new one. If you do try to tackle this and you need to remove some tile in the shower, look for a new valve that comes with what may be called a "remodel" face plate or cover (actually an "escutcheon"), that is the chrome or plastic finishing piece made to cover installation holes - those made specifically for remodel work are larger than those made for new construction work.

Some mixing valves can be disassembled in place for cleaning. Before you start that try to get make and model numbers and go to a plumbing supply house with that info and ask for either a rebuild kit or a washer kit. Once a valve it taken apart it may leak if you neglect to install new washers (acutally "O" rings). This link to the DIY Network site has some good info on this topic: www.diynet.com/diy/hi_plumbing/article/0,2037,DIY_13929_3369183,00.html (http://www.diynet.com/diy/hi_plumbing/article/0,2037,DIY_13929_3369183,00.html)
Have fun.